THE UNIVERSITY OF MICHIGAN INDUSTRY PROGRAM OF THE COLLEGE OF ENGINEERING LANDFILL DISPOSAL OF SLUDGE DERIVED FROM THE LIME/SODA-ASH SOFTENING OF WATER Eugene A. Glysson A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Drexel s of T —t*:. r5 Environmental Engineering 1972 May, 1972 IP-844

ii ACKNOWLEDGMENT In order for this effort to become a reality many people gave much appreciated assistance and encouragement. The College of Engineering of the University of Michigan awarded me a sabbatical leave and the Institute for Science and Technology gave me financial support. The Krando Fellowship awarded me by Drexel University was also most helpful. Appreciation is expressed for the technical advice of Dr. Donald H. Gray, Dr. Frank E. Richart, Jr., and Dr. Walter J. Weber, Jr., who made many helpful suggestions. My thanks to the firm of Ulrich Stoll Associates for computer time, and to the Ann Arbor Water Department for their assistance, and to the University of Michigan, Industry Program for typing and manuscript preparation. The members of my committee, Dr. P.W. Purdom, Dr. A.A. Fungaroli, Dr. C. Silver, Dr. R.J. Schoenberger and Dr. H.C. Wohlers, were very helpful in shaping the final product and their assistance and support are most appreciated.

iii For assistance in technical editing and preparation of the graphics throughout the thesis thanks go to Mr. James Packard and Mr. Cyril Barnes. My special thanks go to Dr. Purdom who as chairman of my thesis committee gave me a great deal of help and encouragement and to my wife, Marie, and my family who gave me so much moral support.

iv TABLE OF CONTENTS Page LIST OF TABLES................................... vi LIST OF ILLUSTRATIONS............................ viii ABSTRACT......................................... xi CHAPTER 1: INTRODUCTION, REVIEW OF LITERATURE, AND OUTLINE OF RESEARCH PERFORMED.... 1 I Introduction......................*** *** * 1 A. Purpose............................... 3 B. Hypothesis............................ 4 C. Methodology........................... 4 D. Exclusions..................*****..* 5 E. Significance.................... 5 II Review of Literature..................... 6 III Outline of Research Performed............ 10 CHAPTER 2: THE CHEMICAL CHARACTERISTICS OF LIME SLUDGE AND THEIR EFFECTS ON ITS USE IN LANDFILL DISPOSAL................. 13 I Electron Microprobe...................... 13 II X-Ray Diffraction........................ 14 III Wet Chemical Analysis.................... 16 IV Test for pH vs Time...................... 20 V Basic Tests for Leachate-Sludge Contact.. 22 VI Tests for Equilibrium Conditions......... 28 VII Tests with Soxhlet Apparatus............. 32 VIII Tests with High-Iron-Content Solution.... 33 IX Tests to Determine Parameters Under Anaerobic Conditions.........*.....*..... 43 X Tests with High-Iron Solutions........... 44 XI Charge on Sludge Particles..49 XII Conclusions................. 51 CHAPTER 3: THE PHYSICAL CHARACTERISTICS OF LIME SLUDGE AND THEIR EFFECTS ON ITS USE IN LANDFILL DISPOSAL................. 53 I Sieve Analysis........................... 54 II Tests for Atterberg Limits............... 56 III Tests for Compaction..................... 56

v Page IV Permeameter Testing....................... 58 V Consolidation Testing..................... 62 VI Consolidation of Layered Systems by Numerical Method....................... 75 VII The Triaxial Test......................... 83 VIII Determination of Cohesion and Angle of Internal Friction................... 87 IX Embankment Calculations................... 91 X Analysis of the Sludge Fabric........... 100 XI Conclusion................................ 105 CHAPTER 4: SOME PRACTICAL APPLICATIONS FOR THE SLUDGE AND METHODS OF HANDLING IT AT A LANDFILL........................... 108 CHAPTER 5: COST ANALYSIS........................ 115 CHAPTER 6: SUMMARY AND CONCLUSIONS.............. 126 BIBLIOGRAPHY..................................... 135 APPENDIX A: ELEMENTAL ANALYSIS.................. 141 APPENDIX B: APPARATUS USED FOR EVALUATION OF CHEMICAL EFFECT..................... 143 APPENDIX C: PHYSICAL TESTING APPARATUS.......... 145 APPENDIX D: ATTERBERG LIMITS DATA............... 151 APPENDIX E: DATA FOR DRY DENSITY VS MOISTURE RELATIONSHIP........................ 152 APPENDIX F: TYPICAL CONSOLIDATION TEST DATA..... 153 APPENDIX G: COMPUTER PRINTOUT OF ANALYSIS OF CONSOLIDATION TEST DATA............. 160 APPENDIX H: CALCULATIONS FOR CONSOLIDATION OF LAYERED SYSTEMS BY NUMERICAL METHOD.............................. 176 APPENDIX I: SAMPLE DATA AND COMPUTATIONS FROM TRIAXIAL TEST....................... 187 VITA............................................. 190

vi LIST OF TABLES Table Page 1. Sludge Analysis by Electron Microprobe...... 15 2. Sludge Analysis by X-Ray Diffraction........ 17 3. Wet Chemical Analysis of Lime/Soda-Ash Sludge..... 19 4. Total Hardness (ppm as CaCO3) - Low Mineral Leachate....... 26 5. Total Hardness (ppm as CaCO3) - Demineralized Water.............. 26 6. Analysis of Variance - Total Hardness - Low Mineral Leachate......................... 27 7. Analysis of Variance - Total Hardness - Demineralized Water......................... 27 8. Finely Divided Sludge in Contact with Demineralized Water......................... 30 9. Results of Surface Contact in Soxhlet, Demineralized Water and Sludge.............. 30 10. Changes in pH and Iron Content Between a High-Iron Bearing Solution and Lime Sludge 35 11. High-Iron Solution in Contact with Sludge Under Anaerobic Conditions.................. 45 12. Increase in Dissolved Solids................ 49 13. Charge on Particle of Lime Sludge........... 50 14. Atterberg Limits of Lime Sludge.......... 56 15. Permeability by Direct Measurement with a Permeameter and Distilled Water............. 61

vii Page 16. Consolidation of Layered System.79 17. Bulk Density of Lime Sludge........ 99 18. Volatile Content of Lime Sludge........... 100 19. Moisture Content of Workable Lime Sludge.. 106 20. Time Study of 2 cu.yd. Dragline........... 117 21. Time Study of 2 cu.yd. Dragline Loading Trucks............................. 119 22. Consolidation by Layers........ 181

viii LIST OF ILLUSTRATIONS Figure Page 1. pH Change Over Time as a Result of Lime Sludge in Contact with Distilled Water..... 21 2. Changes in pH and Alkalinity with Flow of Low Mineral Synthetic Leachate Over Lime Sludge................................ 24 3. Changes in pH and Alkalinity with Flow of Demineralized Water Over Lime Sludge....... 25 4. Changes in pH and Hardness with Time as a Result of Contact Between Finely Divided Lime Sludge and Demineralized Water........ 31 5. Changes in pH and Hardness with Flow of Demineralized Water Over Lime Sludge....... 31 6. Changes in pH with Flow of High-Iron-Bearing Solution Over Lime Sludge.................. 37 7. Iron Retained Per Gram of Sludge with Flow of High-Iron-Bearing Solution Over Lime Sludge............................... 38 8. Iron Removal (milligrams) vs Amount of Lime Sludge (grams)................................ 46 9. Sludge-Particle Size Analysis.............. 55 10. Plasticity Chart........................... 57 11. Variable Head Permeameter...................... 59 12. Void Ratio vs Applied Pressure (100% SludgeFirst Series).............................. 65 13. Void Ratio vs Applied Pressure (20% Sand).. 66 14. Void Ratio vs Applied Pressure (40% Sand).. 67

ix Figure Page 15. Void Ratio vs Applied Pressure (100% SludgeSecond Series).............................. 68 16. Void Ratio vs Permeability (100% Sludge).... 69 17. Void Ratio vs Permeability (20% Sand) 70 18. Void Ratio vs Permeability (40% Sand) 71 19. Relationship Between Permeability Coefficient and Void Ratio of Lime Sludge (Sludge Only).. 73 20. Typical Void Ratio vs Pressure (100% Sludge). 81 21. Consolidation vs Time for 6 Feet of Sludge in One Foot Layers w/100 psf Surcharge...... 82 22. Dry Density of Sludge vs Moisture Content... 85 23. q vs p Diagram Showing Mohr's Envelope (21% Moisture).............................. 89 24. q vs p Diagram Showing Mohr's Envelope (31% Moisture)...... 90 25. Typical Water Content of Compacted Sludge vs Dry Density and Permeability............. 94 26. Stress Difference vs Strain................. 95 27. Typical Stress-Strain Relationship for Certain Materials........................... 96 28. Load vs Strain.............................. 97 29. Typical Failure Plane of Triaxial Specimen.. 98 30. Electron Micrographs of Lime-Soda Ash Sludge (100x, 500x)... 101 31. Electron Micrographs of Lime-Soda Ash Sludge (2000x, 5000x) (1i shown to scale).......... 102 32. Electron Micrographs of Lime-Soda Ash Sludge (10,000x) (lp shown to scale)................ 103 33. Two Typical Traces of Captured Photons from Electron Microprobe During Elemental Analysis of Sludge Samples........................... 141 34. Typical Diffraction Pattern of Sludge Sample by X-Ray Diffraction........................ 142

x Figure Page 35. Apparatus Used for Evaluating the Effect of Leachate Flowing Over the Surface of Sludge.................................. 143 36. Soxhlet Apparatus for Surface Contact of High Iron Containing Solution Showing One Unit Before Application of Solution and One After Several Liters Have Been Passed Over Sludge..................................... 144 37. Karol-Warner Constant Stress Consolidation Apparatus with Sludge Specimen in Place.... 145 38. Geonor-AS Triaxial Test Apparatus with Specimen in Place........................... 146 39. Triaxial Test Specimen at Failure Showing Method of Preparation and Type of Failure 147 40. Permeameters Used for Measuring Coefficient of Permeability (k)........................ 148 41. Permeameter with Sludge Sample Following Permeability Test. Note Consolidation Crack Near Base of Up-Flow Cylinder.149 42. Permeameter Disassembled (Porous Stones Used Top and Bottom Not Shown).... 150 43. Pore Pressure Profiles (1,2,3 - 1 Foot Layers of Sludge).......................... 182 44. Pore Pressure Profile (4 - 1 Foot Layers of Sludge)................................. 183 45. Pore Pressure Profile (5 - 1 Foot Layers of Sludge)................................. 184 46. Pore Pressure Profile (6 - 1 Foot Layers of Sludge)................................. 185 47. Pore Pressure Profile (100 psf Surcharge).. 186

xi ABSTRACT Landfill Disposal of Sludge Derived from the Lime/Soda-Ash Softening of Water Eugene Andrus Glysson Paul Walton Purdom, Sr. The use of landfilling as a means of disposition of the sludge derived from the lime/soda-ash softening of water is investigated. Those chemical and physical characteristics of the lime sludge, as removed from a storage lagoon, which affect its disposal into a landfill are determined. These include elemental analysis of the sludge and changes which occurred in selected non-organic solutions as a result of contact with the sludge under various conditions. The parameters of the sludge which affect its use as a fill material are investigated. These include the determination of the permeability of the sludge, its consolidation characteristics and its sheer strength. As a result of these determinations the possibility of use of the sludge in embankments is considered as well as the extent of its consolidation when used as a fill material.

xii The incorporation of the sludge into a landfill in various ways and the costs thereof is discussed. The recommended method is to use the dried sludge in shallow layers (6 inches to one foot) as a part of the daily cover applied to the landfill. The results of this study indicate that to the extent of this investigation the disposition of the lime sludge into landfill is economical and acceptable with no adverse environmental effects.

1 CHAPTER 1 INTRODUCTION, REVIEW OF LITERATURE, AND OUTLINE OF RESEARCH PERFORMED I. INTRODUCTION The lime/soda ash softening process is often used by municipalities for softening hard water. This process involves the formation of insoluble forms of calcium and magnesium by adding the proper amounts of slaked lime and soda ash. The fundamental chemical reactions involved (without regard to pH adjustment) are as follows: Ca(HCO3)2 + Ca(OH)2 - 2CaC03 + 2H20 (carbonate hardness) (lime) MgCO3 + Ca(OH)2 +- Mg(OH)2+ + CaCO3+ (carbonate hardness) (lime) CaS04 + Na2CO3 + CaC03 + Na2S04 (non-carbonate hardness) (soda ash) These reactions show that in the treatment process, the soluble compounds containing calcium and magnesium are converted to insoluble compounds that can be removed by sedimentation in settling basins. Water-softening plants have been using the lime/ soda-ash process for many years, and their problems of limesludge disposal are familiar. Recently, however, these problems have grown more serious because certain long-standing disposal methods have been rejected as unacceptable. For instance, the common practice of discharging the lime sludge

2 into streams and lakes without treatment is now generally forbidden by water-pollution control agencies. Many water-softening plants have been or are beginning to use lagoons in which the lime sludge can be stored for long periods. During storage, the solids are allowed to re-settle and the supernatent liquid is decanted. This liquid may be discharged into a receiving stream or may be returned to the treatment process. In general, lagoon storage has proved to be economical and satisfactory. The critical factor is limited storage capacity. In some cases, more volume is obtained by making the dikes higher; but sooner or later, every lagoon gets full. When a lagoon does get full, it must either be abandoned or cleaned out. When it is abandoned, a search must be made for a new site that is within an economic haul distance, and is suitable for long-term sludge storage. When a lagoon is cleaned out, all accumulated solids must somehow be removed. Increased urbanization makes abandonment and relocation less and less feasible in most instances. The available land near cities is growing too scarce to be used for indefinite lime-sludge storage. The problem is aggravated by the increase in the number of softening plants now needed to treat municipal water supplies. As stated by Russell et al,(54) "The number of lime softening plants is large and the demand for softened water is so varied and increasingly large, that there is no reason to expect anything but a continual increase in the number of these

3 plants and in the volume of their wastes." Popular demand is forcing more and more cities to adopt some water-softening process. Usually their choice is between the ion-exchange process and the lime/soda process. Largely because the waste brines resulting from the ion-exchange program are hard to dispose of, the lime/soda process is gaining in popularity. But at the same time, the lime sludge resulting from the latter process is being subjected to increasingly stringent disposal controls. For all these reasons, the removal of accumulated lime sludge from existing lagoons is now and will be of considerable interest in the future. A. Purpose The purpose of this study is to determine the feasibility of disposing of the lime sludge by depositing it in landfills. Emphasis is placed on a study of the limesludge characteristics that would affect such disposal to a marked degree. Included in the study is an evaluation of various physical parameters that are helpful in identifying sludge characteristics and in predicting some of its properties as a landfill material. Also included is an evaluation of some of the chemical changes that would result from disposing of lime sludge in landfills, particularly those that are used for general solid-waste disposal.

4 B. Hypotheses In this study, six hypotheses are investigated: 1) The characteristics of the lime sludge are such that it will not pollute ground water or surface water through leaching. 2) In a landfill, the presence of the lime sludge in association with solid wastes will aid in reducing pollutional effects. 3) Under controlled conditions, the lime sludge will serve as a suitable landfill material. 4) Under controlled conditions, the lime sludge can be used for embankments and as a backfill material. 5) If the lime sludge is handled and prepared properly, its characteristics are such that it will permit a mechanized disposal method. 6) The system for lime-sludge disposal will be economically feasible. C. Methodology Four points of methodology are employed in this study: 1) The selected sludge characteristics are determined by various physical and chemical analyses.

5 2) The effects of the sludge characteristics on leachate* are evaluated, as is sludge workability. 3) Field observations for selected engineering methods of excavation and placement are conducted. 4) Excavation and placement costs are estimated from field observations and from other existing data. D. Exclusions Three areas are excluded from the study: 1) Other methods of lime-sludge disposal, and sludges other than lime sludge. 2) Analysis of transportation alternatives such as pipelines and rail haul. 3) Any optimization of site selection for sludge disposal. E. Significance It is anticipated that this study will help to solve the problem of lime-sludge disposal in a technologically * In this study, "leachate" refers to a synthetic liquid consisting of either (1) demineralized water, (2) low, nonorganic mineral leachate, or (3) high-iron, non-organic leachate. None of these three embody all the characteristics of a natural leachate. No attempt has been made to include any organic constituents.

6 sound, economically feasible manner. This disposal method will pollute neither surface waters nor ground waters, and will not create any other environmental problems. Furthermore, it may reveal some beneficial uses for an otherwise wasted material. II. REVIEW OF LITERATURE The magnitude of the overall problem of sludge disposal from water treatment plants has been well stated (32) by Hudson (32) According to him, about one million tons of waste material are generated from municipal water treatment plants annually. This includes all sludges from various water-treatment processes, and not just lime/soda-ash softening sludge. An inventory by the U.S. Public Health Service as of January 1, 1964(64) showed that in the United States, 124 plants were softening water for cities with a population of over 25,000. Waring (65) reports that in 1954, there were 450 municipal lime-softening plants in the United States. (31) Howson states that more than 90 percent of all lime/soda-ash softening plants have to pay for limesludge disposal, and try to get rid of it as cheaply as they can. Usually they put it into lagoons or discharge it into a stream. (By 1972, however, the latter choice is much reduced if not altogether eliminated.)

7 (45) Nelson( indicates the order of magnitude of lime-sludge production by figuring that approximately 2-1/2 pounds of dry softening sludge are produced for every pound of lime that is added during the softening process in the form of commercial quick-lime. Unlike some water-treatment plant sludges - namely alum sludges (Al(OH)3) - lime-softening sludge will dewater itself. In a properly operated lagoon (13,31), they will yield a consistency of about 50 percent moisture on a wetweight basis, which means they can be handled as a semisolid. Alum sludges,on the other hand, are reported(10 to have difficulty yielding a solid content of 20 percent, which means that they require further treatment before landfill disposal. Howson(31) describes the proper operation of limesludge lagoons to produce maximum usage of available volume, so that the stored sludge will contain about 50 percent moisture on a wet-weight basis. In this method of operation, the supernatant liquid must be withdrawn continuously from the lagoon, and the sludge must be deposited in shallow rather than deep layers. (Sludge that contains 50 percent moisture by wet weight can readily be removed from the lagoon by drag-line quipment.) Howson also indicates that lime sludge appears to be readily susceptible to air-drying. One of the general characteristics of lime sludge upon removal from the sedimentation tanks in the softening process is that it settles readily. Black(10) reports that

8 the solids content of softening sludge as it leaves the settling tank will vary from as low as 2 percent to as high as 15 percent. Burgess and Niple(13) report an average of 4 percent solids in softening sludge at five Ohio plants. These solids do not represent a source of pollution in the traditional sense of large organic content or high potential for bacteriological contamination; instead, they present such undesirable characteristics as toxicity from alkaline materials, and turbidity and color which are esthetically objectionable and would interfere with light transmission to the photosynthetic organisms present in the receiving waters. Due to their rapid settling, the solids may present some problems in pumping. Moreover, when settling on the bottom of a receiving body of water, they may adversely affect the benthic growths present there, and end by upsetting the ecological cycle therein. When lime-sludge is discharged into receiving waters, they will usually undergo considerable hardening, since the solids will be returned to solution by contact with the receiving waters. The waters will also undergo an increase in alkalinity and pH. Sheen and Lammers58) report a means of characterizing sludge on the basis of its particle size; in their studies of dried sludge, the average particle size was 5-7 microns, and 96+ percent of the particles passed a 325 mesh screen. Pedersen(47 reports that in an accurate analysis

9 of the dried sludge, 99.8 percent of the particles passed through a 325-mesh screen, whereas a study by Gordon(26) reports that 96 percent passed through a 325-mesh screen. Black(11 characterizes lime sludge by its chemical composition, and reports that composition to range from 87.2-93 percent equivalent calcium carbonate; the other percentage is made up of magnesium oxide, silica, iron, and alumina. Russell(54) states that "A sludge produced by softening of water by the lime-soda ash process consists principally of calcium carbonate with various amounts of ferric, magnesium and aluminum hydroxides." Russelman(55) states that "the impact of a waste may be far reaching and devastating or it may be localized and temporary, but in any case, knowledge of the waste and knowledge of the receiving environment is essential to establish whether pollution occurs, may occur, or is absent. It is precisely this knowledge which is lacking and therefore it is difficult to discuss characteristics of water treatment plant wastes when the'state of the art' is so fragmentary and non-documented." The research reported here on the character of lime/soda-ash sludge and its disposal in a landfill was undertaken in response to statements of this kind.

10 III. OUTLINE OF RESEARCH PERFORMED To carry out this study, several different parameters of the lime/soda-ash sludge were determined and evaluated. These parameters have been divided into two main classifications, according to chemical characteristics and physical characteristics. The research dealing with the chemical characteristics is described in Chapter 2. The studies conducted were: 1. Elemental analysis of the sludge by a. electron microprobe b. x-ray diffraction c. wet chemical analysis 2. Determining change over time of pH of demineralized water in contact with the sludge. 3. Determining changes over time in pH, alkalinity, and hardness as a result of passing a low-mineral leachate and a demineralized water leachate over the sludge at a controlled rate. 4. Determining the results of putting a highmineral (high-iron) leachate in contact with the sludge under aerobic conditions. 5. Determining the results of putting a highiron leachate in contact with the sludge under anaerobic conditions.

11 6. Determining the polarity and magnitude of the charge on the lime sludge particle. 7. Establishing the rate of solution of the lime sludge in demineralized water with pH adjusted to 5.5 with H2S04. The research dealing with the physical characteristics is described in Chapter 3. These studies are subdivided into two subdivisions: the physical characteristics or index properties, and the engineering properties. The parameters evaluated to establish the index properties were: 1. Grain-size distribution by use of hydrometer and standard sieve analysis. 2. Particle morphology by means of the electron microscope. 3. Specific gravity and bulk density. 4, Plasticity and liquid limits by standard soil-testing procedures. 5. pH of the sludge. The studies undertaken to establish the engineering properties were: 1. Permeability by direct measurement with a permeameter and by computation from data developed from the consolidation test. 2. Consolidation test for determining the coefficient of consolidation and the compression index.

12 3. Moisture-density behavior. 4. Shear strength as determined by the triaxial method of analysis. On the basis of an evaluation of these parameters, the lime sludge is classified and the results of its use as a landfill material or as a possible embankment material are discussed. Each phase of the study includes (a) a discussion of the results of the research as applicable to uses of the sludge for various purposes, and (b) the effects of the various parameters as well as a description of the test procedures and apparatus used. Chapter 4 discusses the possible uses of the sludge and some of the methods for placing it in a landfill. These methods are based on information from this study. Chapter 5 presents a cost analysis using a dragline to excavate the sludge from the lagoon and of using a truck to get it to a landfill and a bulldozer to place it there. Chapter 6 presents a summary and the conclusions that can be derived from this study.

13 CHAPTER 2 THE CHEMICAL CHARACTERISTICS OF LIME SLUDGE AND THEIR EFFECTS ON ITS USE IN LANDFILL DISPOSAL Lime soda-ash sludge that is placed in a landfill may come into contact with water in one of two ways - either as rainfall that has not previously come into contact with refuse, or as leachate that has passed through refuse. In order to evaluate and explain the results of such placement, the sludge itself was subjected to elemental analysis by three methods: the electron microprobe, X-ray diffraction, and wet chemical analysis (EDTA). I. ELECTRON MICROPROBE The samples to be analyzed by electron microprobe were first prepared by mounting them on a suitable support and coating them with chromium in a vacuum. [These were the same samples viewed by the electron microscope. Chromium is the standard material for coating samples to be viewed by the electron microscope, and since no chromium was expected to be found in the sludge, the same samples could be used.] A stream of electrons was directed at each sample by the electron microprobe (Applied Research LabARL-MX), and the characteristic X-rays that were emitted by the sample were picked up by a proportional counter.

14 After the results were observed on an oscilloscope, the released X-rays were analyzed and transferred to a recorder for readout. The characteristics of this analysis are such that only approximately quantitative values of the elements can be derived. The sensitivity is very great, however; the X-ray-excited spectograph can detect about -9 10 grams of an element. The results are given in Table 1. The analysis shows that calcium predominates. Some magnesium appears, which can be expected due to the formation of magnesium hydroxide in the softening process. Elemental sulfur appears due to the presence of sulfates in the water. Silica appears due to the turbid condition of the surface water that is being treated in the softening process. As noted above, chromium appears due to the coating of the sludge for analysis. The extreme sensitivity of this method of analysis is indicated by the fact that neither sulfur nor silica were detected in alternative methods of analysis. Photographs of the traces of the accumulated counts (peaks) are given in Figure 31, Appendix A. II. X-RAY DIFFRACTION As a further means of elemental analysis, several samples of lime sludge were analyzed by X-ray diffraction. The apparatus used was a Phillips Electronic Norelco X-ray Diffractometer with an incident radiation (copper k ) of

15 TABLE 1 SLUDGE ANALYSIS BY ELECTRON MICROPROBE (Applied Research Lab - ARL-MX) Energy Energy Level Level from ( Sample Channel Electron Standard Element No. No. Counts Volt e.v. Line 1 50 279 1.276 1.297 Mg k 1.257 166 86 2.290 2.31 S k 315 408 3.622 3.69 Ca k 351 64 3.95 4.01 Ca k 506 233 5.31 5.41 Cr k 563 2 318 421 3.62 Ca k 352 63 3.95 Ca k 507 87 5.31 Cr k 567 19 5.84 Cr k 3 52 53 1.27 Mg k 104 43 1.72 1.74 Si k 164 43 2.29 2.31 S k cx 319 439 Ca k 354 65 Ca k 507 200 Cr k 564 45 Cr k 4 49 216 Mg k 104 100 Si k 165 56 S k 318 728 Ca k 353 101 Ca k 506 64 Cr k 568 16 Cr k 0 47 150 1.25 1.27 Mg k 99 100 1.715 1.77 Si kg 303 1390 3.63 3.69 Ca kc 336 215 3.96 4.01 Ca kg

16 wave length 1.5405A0. The samples were presented as flatplate specimens, and were positioned in the machine for rotation from 10~ to ~ 50. (29) at the rate of 1~ per minute. A typical diffraction pattern of samples analyzed by X-ray diffraction is shown in Figure 32, Appendix A. The "d" values were converted from the measured angles using the NBS X-ray Diffraction Tables.(43) The standards were taken for ASTM X-ray Diffraction Powder Index #5-0586. The results of these analyses are given in Table 2. The results of the X-ray diffraction analyses showed the samples to be comprised entirely of calcium carbonate (calcite); no other material was detected by this method. III. WET CHEMICAL ANALYSIS To quantify the major elements in the sludge, the Ca and the Mg content was determined by wet chemical analysis. Approximately 0.4 grams of sludge were dissolved in hydrochloric acid and the resultant solution was analyzed using the standard EDTA test for Ca and Mg.( The results, shown in Table 3, confirm the conclusion that the sludge consists primarily of calcium carbonate. As a result of this analysis, the lime/soda-ash sludge was determined to be predominately CaCO3 (calcite), with a very small amount of Mg(OH)2 and other miscellaneous substances. The analysis also made it possible to predict (and subsequently confirm) the effects of contact

17 TABLE 2 SLUDGE ANALYSIS BY X-RAY DIFFRACTION d-spacings Relative of Most Intensity Sample Intense of Peaks Probable No. Peaks (A~) (%) Minerals( ) 10-A 3.019 100 2.279 18 1.908 18 CaCO as calcite 1.871 17 2.487 16 11-A-1 3.033 100 2.282'19 2.096 19 CaCO3 as calcite 1.912 18 1.869 18 2.496 14 12-A-2 3.025 100 2.279 18 1.909 18 CaCO3 as calcite 1.872 17 2.489 15 13-A-1 3.032 100 2.281 22 2.093 22 CaCO3 as calcite 1.873 22 1.909 20 2.493 16

18 TABLE 2 (CONT'D) SLUDGE ANALYSIS BY X-RAY DIFFRACTION d-spacings Relative of Most Intensity Sample Intense of Peaks Probable No. Peaks (A~) (%) Minerals PDT-3 3.036 100 2.285 21 2.095 19 CaCO3 as Calcite 1.875 19 2.495 18 1.913 15 PDT-4 3.036 100 2.281 19 1.908 19 1.872 18 CaCO3 as Calcite 2.092 17 2.491 13 PDT-0 3.030 100 2.281 23 2.094 18 CaCO3 as Calcite 1.910 18 1.873 18 2.491 16 PDT-1 3.038 100 2.287 22 1.877 21 CaCO3 as Calcite 2.495 19 2.094 19 1.912 17 ASTM 3.035 100 Standard 2.285 18 X-ray Diffraction 2.095 18 CaCO3 as Calcite Powder 1.913 17 Index File 1.875 17 #5-0586 2.495 14

TABLE 3 WET CHEMICAL ANALYSIS OF LIME SODA-ASH SLUDGE (z 0.4 gm of sludge/liter) Dis- Sus-* (mg/i) % % % Total solved pend. Ca Mg Ca as Mg as Ca Mg CaCO Sample Solids Solids Solids as as CaCO Mg(OH)2 (by (by (by No. (mg/I) (mg/1) (mg/I) Ca Mg (mg/c) (mg/Z) wt) wt) wt) 1 360 357 3 129 16 323 39 35.8 4.4 90.0 2 399 383 16 151 8 378 19 37.8 2.0 94.6 3 401 384 17 148 8 370 19 36.9 2.0 92.4 4 398 381 17 147 10 368 24 36.9 2.5 92.5 5 395 370 25 144 10 360 24 36.5 2.5 91.1 6 401 368 33 146 9 365 23 36.5 2.2 91.1 7 399 388 11 129 19 323 46 32.3 4.8 81.0 8 400 395 5 140 9 350 23 35.0 2.3 87.5 9 402 396 6 138 10 345 25 34.3 2.5 86.1 Suspended solids assumed to be activated carbon or other material not dissolved by acid. H

20 between this material and the water that may pass over or through it. The buffering action of solid CaCO3 is important in this system. IV. TEST FOR pH VS. TIME Weber(66) discusses the buffering effect of solid calcium carbonate in a heterogeneous system where the addition of acid leads to the dissolution of the solid material at equilibrium. He indicates that after being in content for a sufficient time, the pH, alkalinity, and hardness as measured by the presence of Ca and Mg ions in the liquid in contact with the sludge should reach an equilibrium. Water (52) moves over landfill material at a relatively slow rate,2) and percolation through the sludge itself is very slow. Therefore conditions could develop by which equilibrium conditions between the sludge and the solute solution are established. Another test in the present study determined the time required for equilibrium to be reached between the sludge and distilled water. As shown in Figure 1, it proved to be a matter of from two to three hours. If this much contact time occurred in an actual landfill, an equilibrium would be established; otherwise a steady-state condition would develop reflecting the prevailing conditions. This test was carried out using demineralized water with pH adjusted to ~ 5.5. The change in pH was observed with time; in order to maximize the time to reach

21 10..............I LimI Id i n AII ii I AII 4 --- -- -- -- -—. —-- - 3000". --- 9 3 i l l 0 1 2 3 4 5 6 7 8 TIME (hrs) Figure 1. pH Change Over Time as a Result of Lime Sludge in Contact with Distilled Water.

22 an equilibrium, no mixing was provided. It was readily assumed that in a landfill, leachate will be in contact with the sludge for at least two or three hours. V. BASIC TESTS FOR LEACHATE-SLUDGE CONTACT Another objective of the present study was to determine the effects of leachate-sludge contact. Specifically, the question was what would happen in a landfill when lime sludge that had been deposited in layers came into contact with refuse that is generating leachate. A series of trays containing sludge at a 30~ slope was constructed. Two leachates of differing qualities (distilled water and low mineral content) were allowed to flow over the sludge at a controlled rate (25 mk/min). [A high-ironbearing solution was also used, but a soxhlet apparatus was used to determine relationships; see Section VII below.] The low-mineral leachate contained 1000 mg/Q of NaCl and 1000 mg/k of CaCO3. pH was adjusted to 5.0 - 5.2 with H2S04. By analyzing the effluent, the change in pH, hardness and alkalinity versus time could be determined. Each tray was 3 inches wide, 12 inches long, and had 1/2 inch of sludge that was smoothed off so that the leachate would flow evenly over the entire surface. In these experiments, only surface reaction was studied; the sludge was much too impervious to allow for appreciable percolation. The apparatus used is pictured in Figure 33, Appendix B.

23 To determine any noticeable effect, a run was made with the unit continuously flushed with nitrogen gas to simulate anaerobic conditions. When no noticeable changes were observed, all subsequent tests were carried out within the enclosure of the unit. Evaporation was thereby avoided, but there was no provision to control the oxygen level. Samples of the leachate (100 mi each) were collected for analysis as the flow left the chamber. The results of typical surface reactions with lowmineral leachate and demineralized water are shown in Figures 2 and 3. In essence, the pH levels off between pH 8 and 9 (or between 9 and 10 for demineralized water), and the alkalinity levels off at between 30 and 70 mg/h as CaCO3 ( or between 50 and 80 for demineralized water). As a result of contact with the sludge, a leachate with a relatively high acid content (low pH) will be neutralized to an alkaline pH (8 - 10) and will not have as adverse an effect on the environment. The alkalinity will be modified to a level that is much more acceptable in the environment. As shown in Figure 3, large peaks in alkalinity appear in the curves for the first portions of effluent. They can be attributed to the erosion of the finely divided sludge which is washed off the surface in the first flush. Thereafter, the solids are not eroded to any extent and the alkalinity more nearly reflects the effect of contact with the sludge.

24 0 1 2 3 4 5 6 7 8 9 10 RUNS (100 mt portions) 140 LOW MINERAL 12 \______ SYNTHETIC LEACHATE 120Sam e No. *Sample No. 8-1 Sample No. 8-3 100 — y u \ --- --- ---' x Sample No. 9-1 o fn \ A Sample No. 9-3 80 40 20 0 1 2 3 4 5 6 7 8 9 10 RUNS (100 mI portions) Figure 2. Changes in pH and Alkalinity with Flow of Low-Mineral Synthetic Leachate Over Lime Sludge.

25 10 8l — __I I __I _1 0_4 13 6 0 1 2 3 4 5 6 7 8 9 10 FLOW OF LEACHATE (liters) 290 270 I230 FLOW OF LEACHATE (.i.ers.) 210 Q 190 E 1- 170 150.. 130 110 90 70 50 -4 0 2 3 4 5 6 7 8 9 lC FLOW OF LEACHATE (liters) Figure 3. Changes in pH and Alkalinity with Flow of Demineralized Water Over Lime Sludge.

26 After flowing over the various sludge samples, the low-mineral leachate and demineralized water were also analyzed for total hardness. The observed results are tabulated in Tables 4 and 5. TABLE 4 TOTAL HARDNESS (ppm as CaCO3) - LOW MINERAL LEACHATE Sample Time 10-1 11-1 12-1 8 880 850 900 24 940 910 1020 40 930 920 940 TABLE 5 TOTAL HARDNESS (ppm as CaCO3) - DEMINERALIZED WATER Sample Time 10-4 11-4 12-4 13-4 8 140 130 110 105 24 80 60 95 60 40 40 50 75 58 These results were such that an analysis of variance had to be carried out. First, it was necessary to determine whether there was any difference between samples; second, it was necessary to determine whether there was any

27 significant difference in hardness with time. The results of the analysis of variance computations are given in Tables 6 and 7. TABLE 6 ANALYSIS OF VARIANCE - TOTAL HARDNESS - LOW-MINERAL LEACHATE Degree of Source Sum of Squares Freedom Mean Square Sample.55 2.275 Time 1.00 2.50 Error.24 4.06 TOTAL 1.79 8.275 F.065 -4.6 F =6.9 Sample.0 6 0 =69 2,4 Time.0605 Fime = * =8F33 F05 = 6.9 DF2,4 TABLE 7 ANALYSIS OF VARIANCE - TOTAL HARDNESS - DEMINERALIZED WATER Degree of Source Sum of Squares Degree of Mean Square Freedom Sample 6.2 3 3.07 Time 91.9 2 45.9 Error 9.5 6 m 1.6 TOTAL 107.6 111 _ 3.07 FSample = = 1.92 F05 = 4.76 e 3,6 FTime = -=28.7 F 0 5 = 5.14 _____ 1,6.0.

28 The computations in Table 6 show no difference between samples, but show a significant difference in hardness with time at the five percent level. This indicates that the hardness will increase with time of leachate exposure to the sludge, and that the increase reaches an equilibrium which is established by the solubility of the calcium carbonate (calcite). In this case, the equilibrium solubility is at approximately 950 mg/l (as CaCO3) total hardness. The computations in Table 7 show no significant difference between sludge samples, but show a significant difference in hardness with time, with 5 percent chance of error. The initial increase in hardness is caused by the erosion of the finely divided materials; when they are removed, the increase falls to approximately 50 mg/l (as CaCO3) total hardness. VI. TESTS FOR EQUILIBRIUM CONDITIONS Two other tests were designed and conducted to study the effects of the contact between the lime sludge and demineralized water (pH adjusted to ~ 5.0). One test was designed so that equilibrium conditions between the demineralized water and the sludge would be assured. This was accomplished by grinding the sludge to a fine powder, putting an excess of the powder (one gram) into an Erlenmeyer flask containing 500 milliliters of solute solution, and shaking vigorously for varying amounts

29 of time. After being shaken, the mixture in each case was centrifuged for 5 minutes and the supernatant was analyzed for pH and total hardness. [Total hardness was measured by the standard EDTA method, using the Hach water analysis apparatus.] The results are shown in Table 8 and plotted in Figure 4. It is evident that equilibrium conditions were developed at pH 9.6 to 9.8 and total hardness of 50 - 55 mg/9 as CaCO3. The chemical relationships which justify this conclusion are as follows: The solubility product of -8.3. 2+ 2- -8 3 calcium carbonate is 1083, i.e. [Ca2 +][CO2 = 10 At pH 10.4 or above (pK2 of H2CO3) [Ca2] + [C0 ] if dis2+ solution of CaCO3 is the only source of Ca, while at a pH 2+ 2- - 2of 9.5, i.e. [Ca2+] Z [CO ] + [HCO3] and [HCO3] 10[CO3 then [Ca2] ].1[CO-.(66) The observed calcium content 2+ -3 2+ of 50 mg Ca2+ / as CaCO3 is equal to.5 x 10 3 moles Ca /A. -3 The resultant solubility product computation is [.5 x 10 ].1[.5 x 10 ] =.25 x 107 which indicates that the solution contains slightly more calcium carbonate in solution than would theoretically occur at equilibrium. Since equilibrium conditions developed in a very short time (less than 5 minutes) with vigorous shaking, the reaction is not considered time-dependent. In a landfill, with the character of the sludge causing a slow rate of percolation, it is reasonable to expect that equilibrium conditions will prevail and that similar effects will occur.

30 TABLE 8 FINELY DIVIDED SLUDGE IN CONTACT WITH DEMINERALIZED WATER (Water @ pH = 5.0, Zero Hardness) Shaking Time Amount of Sludge Total Hardness (minutes) (grams) pH (mg/Z as CaCO3) 5 1 9.6 50 10 1 9.8 50 20 1 9.8 50 10 2 9.8 55 TABLE 9 RESULTS OF SURFACE CONTACT IN SOXHLET, DEMINERALIZED WATER AND SLUDGE (Water @ pH = 4.0, Zero Hardness, Applied at the Rate of 1 Liter per Hour) Leachate Passed Total Hardness pH (mP) (mg/k as CaCO3) pH SoKhlet #1 300 180 9.8 86,79 600 120 9.65 grams of 900 105 9.7 sludge 1400 70 9.8 2050 65 9.7 2500 55 9.8 2900 65 9.6 Soxhlet #2 300 220 9.8 82.84 600 115 9.7 grams of 900 90 9.7 sludge 1500 65 9.8 2150 60 9.6 2700 55 9.6 3000 55 9.6

31 55 50 --, - 10 C" 50 -- -^.i ___ _ _\ ___......... C) 40 9 03 rpH 2 10- 6 >-r o- ~ * a Hardness oU —---— 5 0........ I.......... 5 0 5 10 15 20 TIME (minutes) Figure 4. Changes in pH and Hardness with Time as a Result of Contact Between Finely Divided Lime Sludge and Demineralized Water. a. <~~~~ * Run No. 1 Hardness -200 rCV5>200 J^~ ~a Run No. 2 Hardness 12 lf/ <_______. ~ pH Run No. 1 ~ pH Run No. 2 ^ 40 y ------------------------------ 6.0 OI -— I 1 14 0 0 400 800 1200 1600 2000 2400 2800 3200 VOLUME OF LEACHATE PASSED (m2) Figure 5. Changes in pH and Hardness with Flow of Demineralized Water Over Lime Sludge.

32 VII. TESTS WITH SOXHLET APPARATUS The results of contact between the sludge and demineralized water were further tested by use of the soxhlet apparatus. The soxhlet flask was filled with dried sludge in lumps that were 1/4 inch in diameter or smaller. Glass beads and a plastic mesh screen served as an underdrain system. With this arrangement (which was identical to that used in the high-iron-solution tests) the liquid could be passed over the sludge at a controlled rate (1 liter per hour), and a saturated condition could be maintained in the sludge. Samples of the leachate after passing over the sludge were taken and analyzed for total hardness and pH. As shown in Table 9 and Figure 5, the pH of the leachate before entering the soxhlet was 4.0, and the leachate had 0 hardness. The first few hundred milliliters of leachate that left the apparatus had a high value of hardness; this was caused by a washing out of the very finely divided sludge present in the soxhlet. Thereafter, the total hardness was between 55 and 65 mg/9 as CaCO3, and pH was 9.6 to 9.8. These conditions were nearly the same as those prevailing when the samples had been shaken together in the previous analysis. Such conditions are more akin to field conditions than others, and because of the large particle size, equilibrium conditions may take somewhat longer to develop. Even so, an apparent equilibrium is developed well within trEe time of contact that would be expected to

33 occur in a landfill. From the results it is very evident that lime sludge will act as an effective neutralizing media in a landfill, and with one exception will not contribute significantly to any pollutional effects. That exception is in raising the hardness approximately 50 mg/i as CaCO3. The amount of sludge taken into solution by a leachate will be affected by its pH and mineral content, which in turn determine its equilibrium concentration. VIII. TESTS WITH HIGH-IRON-CONTENT SOLUTION To determine the results of a high-mineral (highiron) solution in contact with lime/soda-ash sludge, a series of tests were developed and conducted using dried sludge and soxhlet extraction apparatus and a high-ironcontent solution. A solution with 300 mg/9 of ferrous iron was prepared with pH of 4.6. [Due to the solubility characteristics of iron, a low pH was needed to develop a high iron content.] A known weight of dried sludge in random lumps ranging in size from very small to approximately 1/2 inch diameter was placed in a soxhlet extractor. Glass beads and a piece of plastic screen served as an underdrain system. To aid in distributing the incoming solution, a fine-mesh, nickle-wire screen was placed over the sludge layer. A regulated syphon system was established to allow the solution to enter at a given rate (1 liter/hour), and samples were taken from the end of each liter after the solution passed over the sludge in the soxhlet. The

34 soxhlet apparatus was selected so that a saturated condition could develop intermittently in the sludge. The soxhlet extraction apparatus (shown in Figure 34, Appendix B) is equipped with a self-starting syphon which floods the contents intermittently before they are discharged from the apparatus. The solution leaving the soxhlet was analyzed for total iron by the 1,10 Phenanthroline Method (Hach-water analysis apparatus) and pH. Furthermore, a sample of the solution before entering the soxhlet was taken at each liter interval to monitor any change that may have occurred during storage. The results of the various series of tests are as given in the Table 10 and are plotted in Figure 6, 7, and 8. The results show that iron was removed in two ways, basically: 1. Precipitation after contact with the alkaline sludge resulted in an increase of pH up to 6 or 7. Iron precipitates in this pH range are most likely in the form of Fe(OH)3 or FeCO3 and possibly Fe(OH)2, depending on the oxidizing state of the iron. From the observed leveling off of pH at 6+ to 7.0 it can be assumed that the iron in solution is reacting in this situation in one of the following two reactions.

TABLE 10 CHANGES IN pH AND IRON CONTENT BETWEEN A HIGH-IRON-BEARING SOLUTION AND LIME SLUDGE (Fe as total iron) Liters of Fe retained leachate Fe cone. Fe cone. Fe per gram EFe over sample before after retained sludge retained 1 1/hr.(hours) mg/k mg/9 mg/Z mg//gm mg/Z/gm pH Series #1 1 270 200 70.89.89 5.6 78.25 gm 2 180 150 30.38 1.27 5.6 Sludge 3 190 150 40.51 1.78 6.0 4 230 125 105 1.34 3.12 6.4 6 280 190 90 1.15 4.27 6.2 8 300 250 50.64 4.91 6.4 10 244 194 50.64 5.55 6.3 12 180 126 54.69 6.24 6.4 Series #2 1 300 185 115 1.54 1.54 74.6 gm 2 300 230 70.94 2.48 6.0 Sludge 3 300 210 90 1.21 3.69 5.7 4 300 205 95 1.27 4.96 5.6 5 300 230 70.94 5.90 5.5 Series #3 1 300 93 207 1.95 1.95 7.4 106.18 gm 2 300 166 134 1.26 3.21 6.9 Sludge 3 300 190 110 1.03 4.24 6.6 4 280 160 120 1.13 5.37 6.6 5 270 178 92.87 6.24 6.3 Series #4 1 300 140 160 1.75 1.75 6.7 91.47 gm 2 300 170 130 1.42 3.17 6.7 Sludge 3 300 180 120 1.31 4.48 6.3 4 300 170 130 1.42 5.50 6.0 5 300 180 120 1.31 7.21 5.9 uL

TABLE 10 (CONT'D) CHANGES IN pH AND IRON CONTENT BETWEEN A HIGH-IRON-BEARING SOLUTION AND LIME SLUDGE (Fe as total iron) Liters of Fe retained leachate Fe cone. Fe cone. Fe per gram ZFe over sample before after retained sludge retained 1 1/hr.(hours) mg/k mg/k mg/k mg/f/gm mg/i/gm pH Series #5 1 425 268 157 2.02 2.02 77.59 gm 2 420 288 132 1.70 3.72 6.1 Sludge 3 432 335 97 1.25 4.97 6.1 4 448 340 108 1.39 6.36 6.1 5 450 360 90 1.16 7.52 6.1 Series #6 2 290 196 94 1.25 1.25 6.3 75.15 gm 6 284 236 48.64 1.89 6.2 Sludge 7 276 166 110 1.46 3.35 6.0 8 290 222 68.905 4.25 5.8 9 298 230 68.905 5.16 5.9 10 300 240 60.80 5.96 5.8 Series #7 2 290 250 40.66.66 6.1 61.18 gm 6 284 206 78 1.28 1.94 6.1 Sludge 7 276 188 88 1.44 3.38 6.0 8 290 240 50.82 4.20 5.6 9 298 238 60.98 5.18 5.7 10 300 236 64 1.05 6.23 5.9 0u

37 8.0 7.0 (D 0 1 2 3 4 i 6 7 A 4 3' 0 11 21 LITERS OF LEACHATE OVER SLUDGE IFigure 6. Change in pH With Flow of High-IronBearing Solution Over Lime Sludge.

38 1.7 1.6 _ 1.5 --- 1.4 il —------ 1.3 1.2 --- 11. —11.0 0.9 0.8 0. 7 0. —----- 9 10 2 3 4 5 6 7 8 9 10 LITERS LEACHATE PASSING Figure 7. Iron Retained per Gram of Sludge with Flow of HighIron-Bearing Solution and Lime Sludge.

39 Fe2+ + H20 Fe(OH) + H+ 3+ + + Fe3 + 2H20 + Fe(OH)2+ + 2H+ and, depending upon pH, higher order hydrolysis reactions. The released H then reacts as follows; 2- +H + HC CO3 + H + HCO3 ++ HCO +H + H2CO3 H CO + H20 HCO3 + H O3 The pk value of the latter reaction is 6.36.4 which is considered to represent the observed condition since the observed pH is 6.0+ (it is well to note that the carbonate system is a well buffered system at about pH of 6.4 as indicated by Weber(66)). 2. Some oxidation of the ferrous iron to ferric iron was a result of oxygen being available from the atmosphere. This supply would not be available in an anaerobic situation. One result of the formation of insoluble precipitation of iron was its continued precipitation in the discharge tubing of the soxhlet apparatus and in the effluent containers. To account for the passage of iron into and out of the system, a materials balance of the system was attempted. It failed, however, due to the fact that an unknown

40 amount of very fine sludge developed during the drying process was also removed. It is significant that soluble iron was converted to an insoluble form by contact with the lime sludge; this would reduce the amount of soluble iron appearing in a leachate from a landfill in which lime sludge has been incorporated. The conversion also indicates that any treatment to reduce the pollutional potential of leachate should include some form of lime treatment to reduce the iron content. The rate of iron removal decreased but did not go to 0 because a certain amount of unreacted lime-sludge surface remained present. A compromise has to be made here between particle size and porosity, since smaller particles increase the capacity of the sludge as a contact media, but at the same time decrease the ability of leachate to pass over the sludge. The results of the contact of highiron solution and sludge are shown in Table 10. The iron-test results led to two key interpretations: 1. There was a loss of weight from the soxhlet. This was due to: a. erosion caused by dried sludge which pulverized and washed away with leachate; b. solution of calcium. At a pH of approximately 6 very little carbonate as such is available to precipitate calcium so that the solution of calcium would be

41 quite high if equilibrium conditions pretained. Based on the observed results steady state conditions are considered to prevail accounting for the leveling off of the pH at 6.0+ noted in the data rather than equilibrium conditions. Due to the low pH the solubility of calcium is increased and the system is therefore farther removed from equilibrium. The time required to reach the more remote equilibrium thus may be anticipated to be longer. This is shown schematically in the accompanying sketch which illustrates that more time is needed to reach an equilibrium condition in the high iron containing, low pH, system. pH6 - H D | rIron Containing System 0 C pH9+ Demineralized Water TIME Since the residence time in the soxhlet apparatus is relatively short at the rate of application used (1 liter/hr) it is

42 apparent that steady state rather than equilibrium conditions are most likely to occur. These deductions can be drawn from the discussion of carbonate equilibrium after Weber.66) [The conclusion is that most of the loss was due to flushing out of fines by leachate.] 2. The iron concentration was decreased. This was due to: a. precipate of iron as the carbonate and hydroxide resulting from an increase in pH due to the reaction between the acid leachate and the alkaline sludge; b. precipitate of iron resulting from the formation of Fe(OH)3 due to contact with oxygen from the air; c. physical retention of iron on the sludge particles by adsorption. Solubility of ferrous carbonate (FeCO3) at 20~C is 65 mg/9 as FeCO3, and the solubility of ferrous hydroxide is 7 mg/k as Fe(OH)2.(63) As the source of iron in the solution, iron in the form of ferrous ammonium sulfate was used. This is Mohr's salt, commonly used as a source of ferrous ions because it is much more resistant to atmospheric oxidation than ferrous sulfate alone. It was made up to 300 mg/i as ferrous iron with a pH of 4.4 to 4.6.

43 The precipitate formed as a result of contact with the lime sludge was Fe(OH)2. It was green due to contact with air; otherwise it would be white.(15) The green precipitate that was first observed converted to reddish brown, signifying that the ferrous iron had oxidized to ferric. Therefore Fe(OH)3 was assumed to be the precipitate. IX. TESTS TO DETERMINE PARAMETERS UNDER ANAEROBIC CONDITIONS Anaerobic conditions predominate within a landfill, but aerobic conditions also exist either prior to or simul(51) taneously with anaerobic conditions. To determine the parameters under anaerobic conditions, a series of tests were run with nitrogen replacing air in closed bottles. In order to establish the iron-retaining capacity of the sludge, a series of tests were developed. In this series, a known amount of dried sludge, finely divided, was placed in a known volume and concentration of high-iron solution (~ 300 - 450 mg/l Fe). Then the mixture was shaken for various lengths of time in an anaerobic environment. In each series, a measured amount of dried lime sludge and the known amount of solution were placed in a closed glass container and the air replaced with nitrogen. The solution itself was notdeaired. The mixture was shaken constantly at 180 cycles/second for various lengths of time. It soon became apparent that the reactions were not timedependent, since the results were the same at all times exceeding 2-3 minutes. For all tests, therefore, a 2-hour

44 time was decided upon. This was long enough for all potential reactions to take place, and yet was less than the expected time of contact within a landfill between the sludge and any leachate. After shaking, a 25-milliliter sample of the mixture was centrifuged for 5 minutes to separate the solids from solution; then the iron remaining in solution was determined using the same technique used in all the iron determinations (1,10- Phenanthroline method and the Hach water analysis apparatus). X. TESTS WITH HIGH-IRON SOLUTION The first series were conducted using from 1-15 grams of dried sludge and 500 ml of the high-iron (300 mg/9) solution in a 1.5-liter flask. This proved to be an insufficient supply of iron, since the iron was completely exhausted by the 15 grams of sludge. The result was an inconclusive evaluation of the total capability of the lime sludge to react with the iron in the solution under anaerobic conditions. Therefore a subsequent series of tests was set up, making a much greater amount of total iron available (2200 mg or more) in five liters of solution (450 mg/i or 2+ more as Fe ) at a temperature of 20~C. The results of these runs are given in Table 11 and shown in Figure 8.

45 TABLE 11 HIGH-IRON SOLUTION IN CONTACT WITH SLUDGE UNDER ANAEROBIC CONDITIONS Iron in Grams Iron Iron Total Iron Leachate of Remaining Removed Removed Series mg/2 Sludge pH mg/i mg/m mg #4 450 2.5 6.1 364 86 430 5 liter 450 5.0 6.2 368 82 410 450 7.5 6.6 324 126 630 #5 450 8 6.3 346 104 520 5 liter 450 9 6.4 330 120 600 700 20 6.5 490 210 1050 #6 450 10 6.4 328 122 610 5 liter 450 13 6.4 318 132 660 450 16 6.5 254 196 980 450 20 6.5 204 240 1230 The results of this investigation show that the sludge has a great ability (a) to react with a high-iron solution, and (b) to produce an insoluble complex that will remove much of the iron from the solution. [In these determinations, the pH of the mixture was consistently found to be above 6 so that the iron could be assumed to have a negative charge as well.](35) The relationship of iron removed by lime (finely divided) in an anaerobic environment is shown in Figure 8. A straight line has been fitted to this data by the method of least squares, and the equation of the resultant line has been determined. The equation is:

SLUDGE - GRAMS DRY WEIGHT -- -J --- --- --- ---- r *" 3.... 0 ~ H C) z Co 0 o0 0 (D _ _ _ _rI 1-hO 0 ~ C O <~ 0 D- -1 0. U3 (3 fl N) m ~io

47 y = -4.1 +.0214 x y = the grams of finely divided dry lime sludge x = the milligrams of iron (as Fe++) removed. The standard error of estimate for this relationship is 1.73 grams and the coefficient of correlation is.955. It should be noted that this relationship applies only for = 200 mg of iron or more. The fact that the curve does not pass through the origin is attributed to the small amount of iron absorbed on the surface of the glass and to the presence of dissolved oxygen in the solution. By means of the empirical relationship derived, it is possible to estimate (a) the amount of iron that can be complexed when lime sludge is used in the finely divided state in an anaerobic environment, or (b) the amount of lime that is needed to remove a given amount of iron. The estimate is not directly applicable to actual landfill situations because the sludge in the landfill will not be finely divided, as in this test, but rather in lumps and in a mass. Although the leaching tests described earlier are more typical of the actual situation, this relationship may be helpful in using lime sludge as a means of leachate treatment. Since the size of the sludge particles was determined by use of the electron microscope to be < 5p, the surface area per gram of sludge could be estimated. The assumptions made: sludge particles are spherical (Area = 7rD2, Volume = 1/6 7rD ); and specific gravity = 2.35.

48 The results: If the diameter is assumed to be 3p, area/gram =.85 m /gram; if the diameter is assumed to 2 be 5p, the area =.51 m /gram. From the curve (Figure 8), it can be computed that 10 grams of sludge will remove 660 mg of Fe. If the 2 surface area per gram is assumed to be.5 m, then 10 grams will have an area of 5 m. Assuming that the reaction taking place is a surface phenomenon, for every gram of sludge of this size, 660/5 = 132 mg of Fe will be removed per square meter of surface area. Although this computation has little real value, it does indicate that under the stated conditions, considerable iron will be retained in the sludge. To establish the rate of solution of the lime sludge in contact with a leachate that has an assured ability to dissolve it, distilled water was adjusted to a pH of 5.0 with H2S04 and an excess of sludge was placed in it. The changes in dissolved solids in the water and pH of the solution were measured over a considerable period of time. No mixing was provided; the temperature was 20~C and saturation was assumed to have occurred after 4 hours. Weyl(68) states that 3-1/2 hours produced 50 percent saturation in a solution with CO2. Figure 1 shows the change in pH with time of contact, and is the basis for establishing both the time of saturation and the pH which will occur after prolonged contact (equilibrium) with the sludge.

49 The increase in dissolved solids is shown in Table 12: TABLE 12 INCREASE IN DISSOLVED SOLIDS Sample mg/k/4 hr. 1 80.0 2 56.0 3 92.0 An average value is 76 mg/Z/4 hr. If it is assumed that this saturated water was replaced with unsaturated water six times during a day, then.304 gm/day will be removed per liter. XI. CHARGE ON SLUDGE PARTICLE To better explain the reaction with iron contained in leachate as affected by contact with lime sludge, the charge on the sludge particles was determined using the method called metachromasy described by Kawamura and Tanaka. A positive-charged colloid was supplied by using methyl glycol chitosan (MGC), and a negative-charged colloid was supplied by potassium polyvinyl alcohol sulfate (PVSK). The indicator, toluidine blue (TB), served to indicate the stoichiometric point. Specifically, 100 ml of a solution containing 300 mg/i of sludge dissolved in distilled water was placed in a beaker. The pH was adjusted to 10 with HC1, and 5 mi

50 of MGC was added. A few drops of TB was added, turning the mixture blue; then titration to a purple endpoint was done with.001N PVSK. After establishing the relationship needed in distilled water (4.10 mi of.001N PVSK was needed to back titrate 5 m9 of MGC), the polarity of the charge and its magnitude were calculated, with results as shown in Table 13. TABLE 13 CHARGE ON PARTICLE OF LIME SLUDGE (5 mk of MGC was added to each solution and then titrated with.001N PVSK to TB endpoint (purple)) Excess Conc.of Needed Over Polarity Charge Sludge mt of Distilled of Magnitude Solution mg/i PVSK Water Charge meg/k Distilled Water 0 4.10 0 1 300 4.89.79 + 7.9x10 4 2 306 4.90.80 + 8.0x10 4 3 301 4.92.82 + 8.2x10 4 4 301 4.82.72 + 7.2x10 4 The pH of this lime sludge was determined to be 10.1, using the standard procedure employed in soil analy(12) sis.(12) Knowledge of this parameter is important in considering use of the lime sludge as a soil sweetener or for other uses which require a high-pH material.

51 XII. CONCLUSIONS The decided iron removal noted in preceding sections can be explained chiefly by three mechanisms. 1. The charge attraction between the positivelycharged sludge particles and negativelycharged iron particles. As stated in (35), ferric hydroxide is negatively charged only above a pH of 6; below that pH value, it has a positive charge. The high-ironcontining solution in contact with the sludge with even a very short time of contact reaches pH of 6 to 6.5, and remains at a pH of near 6 or slightly above 6 as the solution continues to pass over the sludge (see Figure 6). Since this would result in a negative charge being present on the ferric hydroxide, the iron would be removed on the sludge which has a positive charge. 2. Hem (30 states that waters containing more than 1.0 ppm of iron are only going to retain that amount of iron in solution if the pH is low. As the pH of the leachate is increased due to contact with the lime sludge, the soluble iron will be converted to Fe(OH)3 which will precipitate.

52 3. If the leachate containing a reduced form of iron is allowed to remain in an aerobic environment, it may be oxidized to the Fe(III) form and precipitate from solution.(60) The results of passing a high-iron-containing solution over lime sludge so that iron will be retained by the sludge is shown in Figure 7. This curve indicates a gradual reduction in the retentative capacity of the sludge, but shows that even after a large quantity of solution has passed over the sludge (as much as 10 liters), the sludge still has a retentative capacity in excess of.6 mg/i/gram. These results along with the results from the anaerobic experiments show the lime sludge's great capacity to remove iron from a leachate in a landfill. They are the basis for the conclusion that if treatment of such a leachate is contemplated, the use of lime (perhaps lime sludge) should be an essential part of the treatment.

53 CHAPTER 3 THE PHYSICAL CHARACTERISTICS OF LIME SLUDGE AND THEIR EFFECTS ON ITS USE IN LANDFILL DISPOSAL As previously discussed, the lime/soda-ash sludge excavated from storage lagoons has value as a soil additive and as a sweetener to reduce soil pH. The sludge also has potential as an additive to the soils of strip mines to counteract highly acid conditions. These uses are based on the chemical characteristics of the sludge. Other uses are based on its physical characteristics, and these are investigated in the present chapter. Prominent among the latter uses is disposal of the sludge in embankments, structural fills, sub-bases, and backfills. If the sludge is to be used in any of these ways, however, its properties must first be identified and characterized so that suitable conditions can be determined. In the field of soil mechanics, the physcial characteristics of a material are separated from its engineering properties insofar as it is used as a construction or foundation material. The following list separates the various parameters evaluated in this study of lime-soda ash sludge:

54 PHYSICAL CHARACTERISTICS ENGINEERING PROPERTIES (index properties) Grain size distribution Shear strength Particle morphology Moisture-density behavior Specific gravity Compressibility chemical Composition mineralogical Permeability Plasticity pH Once the material is classified and identified according to the physical properties listed above, one can predict (on the basis of experience and empirical relationships) the likely engineering properties of the material (70) or its suitability for given engineering applications. Few of these parameters are known for lime sludge as it is found in a lagoon. In this study, therefore, the sludge was evaluated and the resultant properties were used as a basis for classifying and determining its suitability for various applications. I. SIEVE ANALYSIS The sludge was subjected to sieve analysis followed by hydrometer analysis (ASTM D422-63) (5, with results that are shown in Figure 9. According to the ASTM Particle Identification System, these results indicate that the material is of silt size.

55 0 S-ll-l * S-1 I Z SAMPLE IDENTIFICATION: S-12__ S-12-2 SAND CLAY SILT - FINE MED A.S.T.M. PARTICLE IDENTIFICATION,100 UU.S. STANDARD SIEVE SIZES: 200 100 60 40 60 0 50C - - - - - 50 4 0 I I I 1 " I I 1 90 ------ ----- 0___ 280 --- ----- 20 70 _ / - ----- -- 30 70 _ _ 7 60 g -------— gv - ---- __ _ --- - -_ — __-4_0 50 F —---- ---- - -- -- ----— 50 =LU~Flr../ __. _ _ 0 40O- - ---- ---- — __ — --— 60 30 ---— ~tr- -------- 0 30 i- ~ 1l,. +__ —0- ~ - lo'T —---- - - - ~L.O0.001.01.10 DIAMETER IN MILLIMETERS Figure 9. Sludge-Particle Size Analysis.

56 II. TESTS FOR ATTERBERG LIMITS To determine the ASTM soil classification of the sludge, the Atterberg limit tests (liquid and plastic limits) were conducted on several sludge samples, with results that are shown in Table 14. TABLE 14 ATTERBERG LIMITS OF LIME SLUDGE Liquid Plastic Plasticity ASTM ample Limit Limit Index Classification #1 41.8 35.0 6.8 0 (Liquid limit after oven (Oven dried) after oven drying is less than 3/4 of the original sample before drying) #2 57o7 38.8 18.9 MH (Air dried) #3 57.5 48.2 9.3 MH Natural (as sampled) The locations of these samples on a plasticity chart is shown in Figure 10. The Atterberg limit tests were conducted according to standard ASTM procedures D423 and D424. ) A typical data sheet is shown in Appendix D. III. TESTS FOR COMPACTION Knowledge of the moisture-density relationships or compaction characteristics of the lime sludge is required if it is to provide for reasonable stability in a

60 G troup ^" ----— ^ Sy bolS Typical Names Inorganic silts and very fine __MhL \ sands, rock flour. silt" or 50~{~~~ I' ~ """""" ~clavev fine sands with slight _ _____________ ____-_ __I_____ plasticity Inorganic clays if losw Io CL medium plasticity. gra\ellclavs, sandy clavs. sii\ clavs. i lean clavs! OL \Organic silts and organic silt-' _____ clas of low plasticitv P &P~~s~ 80 \' Inorganic silts, misaceous or 40 "* "a> ^ M/RfH diatomaccous fine sandy or CL silty soils, elastic silts 6^~.B (- ~if~CH Inorganic clavs of high plaslcity,. fat clays U wOH Organic clavs of medium to high C - --- pl^ Ll __pasticity_ 2: p Peat and other highlv oreanic soils Air 1 0r ~~L~~M 0 0 10 -20 30 40 -0 60 70 -80 Ai —--- LIQUID LIMIT, LL Figure 10. Plasticity Chart.

58 rolled embankment or a compacted landfill by itself. These parameters were determined on air-dried sludge, using compactive effort equivalent to the modified AASHO compaction method. As shown later in this study (see the section on Triaxial Testing), the results gave an optimum moisture content of 32 percent (dry weight basis) and a maximum dry density of 81 pcf. It should be noted that as the moisture content of this material increases, the dry density decreases rather rapidly, impairing its usefulness as a landfill material. IV. PERMEAMETER TESTING To further define the engineering properties of the lime sludge and to establish the possible rate of movement of water through it, the coefficient of permeability was evaluated. The evaluation was carried out in two ways;one by use of the permeameter described in this section, the other by means of the consolidation test described in the section following. The permeameters used for measuring the sludges coefficient of permeability were of the variable-head type, and consisted of a plexiglas cylinder with an effective length of 10.59 cm and an inside diameter of 5.00 cm. The 2 cross-sectional area of the permeameter was 19.635 cm. The inside diameter of the burette from which the water was delivered was 1.04 cm. To assure drainage, porous stones.70 cm thick were used at each end of the

59 permeameter. Filter paper was inserted between the sample and the stones. The sludge samples to be tested were placed in the permeameters. No attempt was made to measure the permeability of completely disturbed samples, but the physical placement of the sludge in the permeameter required considerable remolding. The coefficients of permeability obtained by these tests were compared with those calculated from the consolidation tests where the samples were completely distorted. The comparison showed that the method of placing the samples had very little effect. A sketch of the apparatus and the equation used are given in Figure 11. d - (a=-rd) T h h Figure l,'ur (1 VrbA=trD) Figure 11. Variable-Head Permeameter

60 The equation used is: k = 2.3 A( t) log1 (h A1t l-00) 1 h1 -2 a = cross-sectional area of stand pipe (.85cm ) L = length of soil sample in permeameter (10.59cm) -2 A = cross-sectional area of permeameter (19.635cm ) to = time when water level in the standpipe is at ho t = time when the water level in the standpipe is at h ho,hl = the heads between which the permeability is determined The results of evaluating the coefficient of permeability by the use of the falling-head permeameter are given in Table 15. Lambe and Whitman(38) have suggested that soils be classified according to their coefficients of permeability as follows: Degree of Permeability k (cm/sec) High over 10-1 -3 Medium 101 - 10-3 -3 -5 Low 103 - 10 Very low 10-5 - 10-7 Practically impermeable less than 107

61 TABLE 15 PERMEABILITY BY DIRECT MEASUREMENT WITH A PERMEAMETER AND DISTILLED WATER Test No. Permeameter No. 1 Permeameter No. 2 Permeability Permeability cm/sec cm/sec 1 - R1 4.OE-6 2.3E-6 1 - R2 2.1E-6 4.OE-6 1 - R3 2.9E-6 2.3E-6 1 - R4 5.1E-6 2.6E-6 1 - R5 4.4E-6 2.4E-6 2 - Rl 4.7E-6 2.8E-6 2 - R2 5.OE-6 3.1E-6 2 - R3 4.7E-6 3.1E-6 2 - R4 4.1E-6 2.4E-6 2 - R5 4.2E-6 2.4E-6 2 - R6 5.4E-6 3.3E-6 2 - R7 4.7E-6 2.8E-6 2 - R8 4.9E-6 3.OE-6 2 - R9 4.8E-6 2.9E-6 3 - R1 5.8E-6 3.7E-6 3 - R2 5.OE-6 3.OE-6 3 - R3 5.9E-6 3.9E-6 3 - R4 4.5E-6 2.8E-6 3 - R5 6.0E-6 4.1E-6 3 - R6 4.7E-6 3.7E-6

62 As discussed by Wu(69) the permeability coefficient is dependent to a very large extent on the size of the voids in a material, and the size of the voids is in turn largely dependent on the particle-size distribution of the soil. Typical values of permeability coefficients from Terzaghi and Peck(61) are as follows: Permeability Soil Types Coefficient k (cm/sec) Clean gravel 1 - 10 -3 Clean sand; sand and gravel 10 - 1 -6 -3 Very fine sand; silts; 106 - 103 mixture of sand, silt and clay; stratified clay deposits Homogeneous clay 10l All indications are that the lime/soda-ash sludge -5 -7 has a permeability of 10 - 10-7 cm/sec, which is comparable to the range of a silt or silty clay and would be classified as having a very low degree of permeability. V. CONSOLIDATION TESTING The consolidation test was conducted to determine the coefficient of consolidation (Cv), and to permit the calculation of the compression index (Cc). These two coefficients are essential for use in calculations dealing with

63 the amount and rate of settlement that can be expected from the lime/soda-ash sludge. An integral part of the consolidation test is the determination of void ratios; to further evaluate this parameter and also to confirm the coefficient of permeability as measured by the permeameter, the coefficient of permeability was calculated from this test. The test was run on three types of samples. One consisted of the natural sludge alone, one contained 20 percent by weight of 20-30 Ottawa sand, and the third contained 40 percent by weight 20-30 Ottawa sand. Each of the three samples was tested in the same manner. The apparatus used was a standard Karol-Warner constant-stress-load frame with a 2.5-inch floating consolidation ring. The sample to be tested was pressed into the ring, and the weight of the sample was determined. Porous stones were inserted at the top and bottom of the specimen to provide for vertical drainage of the pore water when the load was applied. Then the specimen unit was placed in the load frame, and the chamber was filled to the proper level with water. Loads of 2, 4, 8, 16, 32, and 64 psi were applied in that order. Each load was applied for 12-16 minutes, during which the changes in sample volume were recorded. This length of time was considered adequate for the completion of all primary consolidation; secondary consolidation was considered negligible.

64 In each of the samples containing sand, the dry weight was calculated according to known moisture content; on this basis, 20 percent and 40 percent sand was added, respectively. Then the samples were thoroughly remolded and set into the consolidation ring. Small voids were quite possibly embedded in the sample, accounting for the percentage of saturation exceeding 100 percent. In calculating the consolidation coefficient (c ), both the t50 and t90 values were determined, with results that appear as Method 2 (t50) and Method 1 (t90). A sample of the data collected and the calculation involved are included as Appendix F. The results of the consolidation test were plotted by the square-root-fitting method and also by the logfitting method, so that values of the time for 50 percent (t50) and 90 percent (t90) consolidation could be determined. The actual calculations leading to the values of the consolidation coefficient and coefficient of permeability were done on a computer. The summary data and computer printout are included as Appendix G. Data from this printout are the basis for the curves in figures 12, 13, 14, and 15, which show the relationship between the void ratio (e) and the log of the applied pressure (log p) for the different types of sludge samples. The void ratio (e) versus log of permeability (log k) was plotted as shown in Figures 16, 17, and 18. In samples that included sand of varying amounts (Figures

65 3.0 2.0 0__ 1.0.1.2.4.6.8 1.0 PRESSURE (p) kg/cm2 Figure 12. Void Ratio vs Applied Pressure (100% Sludge, 1st Series)

66 3.0 ____.________._____________.. 2o0 1.0.1 1.0 PRESSURE (p) Kg/cm2 Figure 13. Void Ratio vs Applied Pressure (20% Sand)

67 3.0 2.0 0. ~0~. - 1.0.1. PRESSURE (p) Kg/cm2 Figure 14. Void Ratio vs Applied Pressure (40% Sand)

68 3.0 X 2.0 a) 0 1.0......_______..1.2.4 1.0 4.0 8.0 PRESSURE (p) Kg/cm2 Figure 15. Void Ratio vs Applied Pressure (100% Sludge, 2nd Series)

69 3.0 2.32,g~~~~~~~~~~0~ 0 * S,.v,.. 2.0 1 2 4 6 8 1 2 4 6 8 1.0 00 ee 0.............. e6.___________ xl 7 x10-6 PERMEABILITY (k) cm/sec Figure 16. Void Ratio vs Permeability (100% sludge).

70 3.0 o 2.0 —- -- i — - 2 0 ~ 0 ~ I1 0-~! 0 0 * -.0 -_......,..... 1 2 4 6 8 1 2 4 6 8 1 x10 7 x 106 PERMEABILITY COEFF (k) cm/sec Figure 17. Void Ratio vs Permeability (20% sand).

71 3.0 -' * 0 200 2.0 ----- ---- lll —-- - 1 0 0 I I 1 2 4 6 8 1 2 4 6 8 x1 o07 x10 -6 PERMEABILITY COEFF (k) cm/sec Figure 18. Void Ratio vs Permeability (40% sand). (40% sand).

72 17 and 18) there was no relationship between "e" and "log k"; and the results indicate that other factors besides the void ratio affected the permeability as different sizes of particles were combined. These other factors were particle size, composition, fabric, and degree of saturation.(38) In the case of the pure sludge samples (Figure 16) the particle sizes were more nearly uniform, and the relationship between "e" and "log k" improved. From Figure 16, a trend develops indicating that the permeability increases as the void ratio increases. In any material, the permeability coefficient (k) is dependent to a large extent on the size of the voids in the material. This can be carried further to say, as Wu(69) does, that the permeability coefficient is governed by the shape and size of the voids and the flow path that the water particles follow while moving through the material. By means of the Kozeny-Carmen equation, Wu relates the coefficient of permeability (k) to the void ratio (e) as follows: 3 K = C e "C" is a lumped parameter which is a function of particle shape, tortuosity, and specific surface area for a given soil. Since these do not change with the void ratio, "C" is a constant.

73 10 8 6 Ct x 00f o i 0 1.0 2.0 3.0 4.0 5.0 I) I (Lime sludge only) CFigure 19. Relationship Between Permeability 2 * k = Cem Coefficient of Correlation.81 1.0 2.0 3.0 4.0 5.0 VOID RATIO (e) Figure 19. Relationship Between Permeability

74 In order to determine "C", it is convenient to plot a linear relationship; i.e., if e /l+e e e then k = C eM and log k = log C+M log e, which is a linear function. To establish the relationship of the permeability coefficient (k) and the void ratio (e) in the sample of lime sludge analyzed by the consolidation test, the values of k vs e were plotted on log-log paper as shown in Figure 19. The straight line fitted to the data was determined by the least squares method, and the value of C and M are shown on the curve as well as the correlation coefficient. -8 (C=7.65 x 10, M=3.70) By means of this curve, it is possible to estimate the permeability coefficient by determining the void ratio. (47) Pedersen(47) states that the compression index Ae (C ) can be computed using the relation Cc p where c c Ap e = change in void ratio per logarithmic cycle of stress Ap plp" Ae Values of A from Figures 12 through 15 result in the following: Sample C 1 (sludge only).280 2 (40% sand).0413 3 (20% sand).0856 4 (sludge only).224

75 Lambe and Whitman(38) list several soil types along with their compression indexes. Lime/soda-ash sludge compares with a kaolinite (C =.21 to.26); the more plasc tic soils have higher compression indexes and higher void ratios. In the present study, when sand was added to the lime sludge, the compression index was lowered quite markedly, and the void ratio was reduced to some extent. The lime sludge alone is highly compressible-a fact that can be deduced from its small particle size, its high initial void ratio, its high natural water content, and (as shown in the consolidation test) the large change in its void ratio which occurs with loading. The high primary consolidation observed is due largely to the fact that the applied load causes pore water to be removed from the sludge. VI. CONSOLIDATION OF LAYERED SYSTEMS BY NUMERICAL METHOD Because of the compressibility of the sludge, it will consolidate when placed in a landfill. To determine the amount of consolidation expected when the sludge is deposited in a series of layers one foot thick to a total depth of six feet, with a 100 psf surcharge placed after the sludge is in place, the following numerical method is employed. The theory of one-dimensional consolidation by vertical drainage of water is used. In this theory the primary assumptions are (a) that the soil is initially

76 saturated, (b) the consolidation process is time dependent because of the flow of water out of the soil, (c) the water is considered incompressible as are the solid particles of the soil, (d) the coefficient of permeability and the coefficient of consolidation c are considered to be constant throughout the consolidation process, and (e) the soil is assumed to compress only in the vertical direction with no lateral motion of soil particles and no lateral flow (62) of water. These assumptions are enumerated by Terzaghi(62) The numerical procedure is a means of substituting difference equations for the governing differential equation for consolidation as established by Terzaghi.(62) The basic ground rules for the difference equation substi(53) tution are given by Richart. In this computation the value of A = 1/2 was used which provides the fastest convergence of the solution.(53) -rAt A = 2AZ2 Z = distance below the top surface of a layer t = time Each layer was considered to be placed in its one foot thickness instantaneously and to be saturated instantaneously. When these conditions were met then the time rate of consolidation was calculated by the numerical procedure. Thus the initial pore pressure distribution in each layer varied from 0 at the top surface to 24

77 lbs/sq.ft. at the bottom surface. (Bouyant weight of sludge equals 24 pcf.) The first layer placed was considered to rest upon sand which provided a drainage surface. Therefore this layer drains both top and bottom and H = 1/2 ft. The second layer is assumed to be added instantaneously to the first layer at the end of one day. The second layer eliminates a drainage surface at elevation of 1 foot and now the two drainage surfaces are at elevation 0 and elevation 2ft. Therefore H = 1 ft. for this part of the problem. Initial pore pressure for the 2 ft. total thickness is now 0 at the top varying to 24 lbs/sq.ft. at elevation of 1 ft. and varying in the bottom 1 ft. by 24 lbs. plus whatever residual pore pressure was left at the end of one day. Each succeeding layer added 24 lbs/sq.ft. to the entire thickness of soil below and the top layer had a pressure variation from 0 to 24. The numerical procedure permits a change in pressure conditions within a given layer at any instant of time and it also permits a change in total thickness of all the layers at any instant of time. Therefore it is quite applicable to this problem of superposing layers of saturated material. After the six layers and the 100 lb/sq.ft. surcharge have finally been applied, then of course the numerical procedure permits calculation of the dissipation of pore pressure with time. The time required for 90% consolidation under the final condition should be quite

78 similar to the time determined from the trapezoidal loading [T =.85.(44)] The calculations necessary to determine the consolidation of 6-1 foot layers of sludge each deposited on the other at the end of one day with a final surcharge of 100 psf put in place at the end of six days as described above were carried out. All the steps of the calculations and the resulting curves are provided in Appendix H. The results were as follows: All calculations are based on the sludge having the following characteristics: Moisture content w = 120% on dry weight basis Specific gravity Gs = 2.35 Initial void ratio e = 2.80 Compression index Cc = 0.28 Consolidation coefficient c = 5.0x10-3cmIsec Wet weight of sludge = 85 pcf Bouyant weight of sludge = 24 pcf Note: cv for all samples were within one order of magnitude of one another with a typical value of 5.0 x 10 3 cm/sec (1.93 x 10-2 ft2/hr)

79 TABLE 16 CONSOLIDATION OF LAYERED SYSTEM No. of the one Pore Pressures foot layer o avg Compression placed at end of 24 hr.* #/ft Kg/cm A(inches) VI 10.9.055 1.17 V 127.8.064 1.23 IV 148.8.074 1.29 III 172.8.086 1.36 II 199.8.100 1.45 I 229.0.115 1.55 8.05" *100 psf surcharge placed 24 hours after the sixth sludge layer was placed. The method and calculations used in this method along with the resultant curves showing the pore pressures in the increasingly deeper sludge as each additional layer is placed are shown in Appendix H. As formulated by Richart(53) ATv = A (A) A = 1/2 ATv = 1/2 (A)2 for 6 foot depth A-=l/3 ATv =.0555 xy

80 The number of.0555 time intervals "n" required to result in 90% consolidation in the six layered sludge was found to be 19 nAT = T = 19 x.0555 = 1.05 v V Solving for "n" in the equation as stated by Richart(53)) 2v 24 n =.H2 A H AT v.019 x 24 n =019 x 24.915 days/increment 3 x.0555.915 x 19 increments = 17 days plus 6 for placement, a total of 23 days to achieve 90% consolidation. As a means of relating consolidation of the 6 feet of layered sledge with time, Figure 21 was compiled using average values. Considering the 6 feet of saturated sludge to be placed in a trench all at once and then loaded with a surcharge equal to 100 psf the following consolidation calculations would result. Y' = bouyant weight of sludge = 24 pcf H = 3 feet P0 = 3 x 24 = 72 psf plus 100 psf = 172 psf =.086 kg/cm from Figure 20 e = 2.36

81 0 H 0 lv______ i O. ___.0001.01.01 1.0 10 2 LOG PRESSURE kg/cm Figure 20. Typical Void Ratio vs. Pressure (100% sludge)

82 0 aI) 4 6 8 L ------------- - - ---- 10 ________________________ 6 8 10 12 14 16 18 20 22 24 DAYS FROM START OF PLACEMENT Figure 21. Consolidation vs. Time for 6 Feet of Sludge in One Foot Layers w/100 psf Surcharge

83 Ae 2.80-2.36 A -= x 2H 2.80-23 x 72 = 8.15 l+e 3.80 o which compares well with that calculated by the layered method. Time required for 90% consolidation assuming two way vertical drainage [T =.85 from (44)] T. H2.85x9 =.24.019x24 = 17 days The settlement which does occur will take place within a relatively short time. This means that most of the settlement will be accomplished while the landfill is still being worked so that regrading can be carried out if necessary. VII. THE TRIAXIAL TEST The same method is used for preparing sludge samples for the triaxial test and for determining the relationship between moisture content and density. The samples were compacted by impact compaction,the compactive effort used was equivalent to that in the modified AASHO test. This differed from the standard method only in the use of a smaller compaction mold and a smaller number of lifts. The mold used was 1-3/8 inches in diameter and 2-3/4 inches long. Each sample was compacted in three lifts with 25 blows of the hammer per lift. Sludge samples with various moisture contents were compacted following this standard procedure and their weight and moisture content determined.

84 The resulting curve in Figure 22 shows the relationship of the dry density vs moisture content, and indicates the optimum moisture content (corresponding to maximum density) of the sludge. [All moisture contents are figured on a dry-weight basis.] Sample data from this test are given in Appendix E. The same steps described above are used to prepare samples with known moisture content for use in the triaxial test. Compacted material was used for this test because any sludge material to be used for an embankment will require compaction; it cannot be simply received and dumped. The samples were tested in a Geonor-AS triaxial testing apparatus. As the tests were being conducted, the samples were consolidated and drained. A porous stone placed at the base of the sample helped to provide for drainage. Lateral drainage through the sides of the specimen was provided for by a slotted filter paper enclosure which completely encircled the specimen. Two very thin rubber membranes lubricated by stopcork grease were placed over the package (sample plus drainage provisions), and were held in place by rubber "0" rings. [Two membranes were used instead of one so as to avoid rupture.] After the membranes had been sealed in place, the triaxial chamber was closed, filled with water, and put under the desired confining pressure. This provided for pre-consolidation of the sample.

85 Modified American Association of State Highway Officials Description: Light Gray Silt Optimum Water Content: 32.0% Maximum Density: 81.0 pcf 85 80 X 7 —75 L6 70 - 65 ________________ 15 20 25 30 35 40 45 MOISTURE CONTENT (%) Figure 22. Dry Density of Sludge vs Moisture Content

86 On the basis of the results of the consolidation test, the time required for complete primary consolidation was less than 1/4 hour. To insure complete pre-consolidation under triaxial test conditions, the samples were subjected to the various confining pressures and held for 1 hour before the triaxial test was started. The confining pressures of 10, 20, and 30 psi were chosen because they compare roughly to 10, 20, and 30 feet of normal soil, and the lime sludge is likely to be subject to them in an embankment or a trench. After the pre-consolidation was completed, the triaxial test was carried out on each of the specimens. Following the working rule stated by Bishop and Henkel(9), the strain rate (application of load) was set such that at failure at least 95% degree of consolidation would have developed. Readings were taken of the deflection and the load applied to failure. These data are also included in Appendix I. Six different triaxial tests were conducted. Two different moisture contents (221% and 331%) were used; determinations for samples of this sludge showed optimum moisture to be %32%. Three confining pressures were used for each of the two levels of moisture content. After the tests were completed, the sample was observed for failure characteristics, and its moisture content was determined for use in subsequent calculations.

87 VIII. DETERMINATION OF COHESION AND ANGLE OF INTERNAL FRICTION The p-q diagram described by Lambe and Whitman(38) was used to plot the results of the triaxial test. The points give a value for p and q corresponding to the peak values of maximum stress sustained before failure. The required calculations are as follows: a1 - a3 q= 1 =3 3 + stress difference as q 2 measured from the results of the triaxial test. It is the dial load converted to stress. 3 = confining pressure. 1 - 3 = stress difference, some times referred to as the normal stress. a1 +a3 stress difference plus 2a3 P = 2 2= (a 1-3) + 2a3 2 3 varies according to values of confining pressure 10 psi =.703 kg/cm2 20 psi = 1.406 kg/cm2 30 psi = 2.109 kg/cm2

88 Moisture Content 221% (Dial reading at failure converted to) Stress Stress (q) (p) difference Sample 23 a3 -a 3 3 3 3Sample) 1 3 1(al-3) +23 (1a'a3)+23 No. (kg/cm) 2 2 2 7.703 5.56 2.78 6.966 3.483 1 1.406 8.095 4.05 10.907 5.453 2 2.109 9.306 4.65 13.524 6.762 Moisture Content z31% (Dial Reading) () (p Stress difference Sample 3 a +a No. (kg/cm2) (a 1a 3) ( a-a)+2 3 2 5.703 6.25 3.13 7.656 3.828 6 1.406 7.41 3.70 10.222 5.111 4 2.109 8.37 4.18 12.588 6.294 The data in these calculations are plotted in Figures 23 and 24. These calculations allow the values of c (cohesion) and $ (an4le internal of friction) to be computed as shown, giving values for: 21% moisture (below optimum moisture) = 1.595 kg/cm 21% moisture (below optimum mois~ture) 4i = 28.60 31% moisture (approx. optimum moisture)c = 1.645 kg/cm2 ~ = 24.3~

89.....I...I I 4o~`~ 0 ('kf line a =.40 =1.-40 c=1.595 kg/cm2 t 3.35 _ 1 I tan.0 a = a.478 = arc sin tan a = 28.6~ 0 1 2 3 4 5 6 7 P Figure 23. q vs p Diagram Showing Mohr's Envelope (21% moisture).

90 5) 1 1 4 NOVA kf line )-f 2,^^1^ ~tan a =.412 \ = arc sin tan a = 24.3~ 1 a50 la =1.50 = 1.645 kg/cm2 al.50cos 0 1 2 3 4 5 6 7 Figure 24. q vs p Diagram Showing Mohr's Envelope (31% Moisture).

91 (38) Lambe & Whitman(38) summarize friction angles for various soil classifications and show that for design purposes, silt (non-plastic) has a P ranging from 26~ - 30~ at ultimate strength. The values determined from the present research compare very well with these observed values. It should be noted that the strength parameter obtained from the triaxial test was obtained at nearly optimum moisture content and maximum dry density. Values developed in the field would be somewhat lower, with an upper limit being a relative compaction of perhaps 90% of maximum dry density. As seen in Figure 22, at moisture contents below optimum, the dry density is relatively insensitive to moisture content. At moisture contents above optimum, however, the density falls off rather sharply. In the triaxial test, shear-strength parameters were developed for samples molded at or near the optimum moisture content and on the dry side of optimum. Since the shear strength of sludge on the wet side of optimum was clearly low, samples were molded at 31% and z21% moisture figures cited earlier. IX. EMBANKMENT CALCULATIONS Lambe(38) suggests as a rule of thumb that it is unwise to use material for diking purposes at a slope (angle of inclination) higher than the effective angle of internal friction. (Assuming no cohesion.) In the case of lime sludge (assuming no cohesion and no seepage), this

92 would limit an embankment to something less than a slope of 24~. But the lime sludge overcomes these limitations because it shows considerable cohesion. The following computations illustrate the slope stability of this material, and indicate possible slope heights when it is used as an embankment. These computations are based on the results of the triaxial tests, which showed the lime sludge to have an angle of internal friction (0) of from 24~ to 28~ and a cohesion value of about 1.6 kg/cm (3260 psf). The wet density of the sludge was 107 pcf (Yw). The stability factor N is a function of B the slope angle and 0 the angle of internal friction.(61) It is calculated according to the equation: YHc N = where y = unit weight s c H = critical slope height c = cohesion On the bases of curves from Terzaghi and Peck(61, these results are obtained: 0 = 25~ N = 20~ C = 3260 psf H = C = 3260 psf C Y Ya= 107 pcf Yw= 107 pcf F.S. = 1 F.S. = 1 _ Ns Hc _ Ns c 50~ 15 460 50~ 13.5 410 60~ 12 360 60~ 10 300 70~ 9.5 290 70~ 8.5 260 80~ 7.5 230 80~ 6.5 200

93 It should be noted that at a safety factor of one, the heights H cited above are critical (impending c failure). In practice, a safety factor of more than one should be used. A safety factor of two on the cohesion would reduce the Hc by 1/2. Since the above values are based on compacted sludge with nearly optimum moisture content, they are somewhat higher than the values resulting from the usual degrees of compaction in the field. Another consideration is relative to the use of lime/soda-ash as an embankment: that is the performance of the material upon sudden drawdown or seepage. According to Lambe 38, for dry or completely submerged slopes in cohesionless soils, the factor of safety is tan ^ (F.S.) = Eita tan 8 where 4 is the effective angle of internal friction and a is the angle of inclination of the slope of the embankment. If sudden drawdown occurs, the safety-factor equation is modified by the ratio of the buoyant unit we weight over the total unit weight F.S. = b tan * For most soils yb 1/2; but for yt tan - Yt lime sludge, Y- =2/5. The foregoing is cited merely to yt show how pore water pressure and seepage will reduce the safety factor in stability analysis. Due to small particle

94 size, the surface of the sludge should be protected from erosion if this material is used in an embankment. The line/soda-ash sludge can also be used as an impervious core for an earth-fill embankment. In this application, the sludge would be compacted during placement; therefore its impermeability would be improved. Experience has shown that for maximum reduction in the permeability of clayey silts (38), the material should be compacted just slightly on the wet side of the optimum moisture. A schematic illustration of this is given in Figure 25. By such a change in moisture, the permeability can be reduced by one order of magnitude. PERMEABILITY cm/sec ID DRY DENSITY lI (Yd) gm/cm3 WATER CONTENT % FROM LAMBE AND WHITMAN (38) Figure 25. Typical Water Content of Compacted Sludge vs Dry Density and Permeability.

95 * ~ 31% moisture ** 21% moisture ( ) confining pressure 10. 8. (30psi) I // j ~7' (20psi) 6.0 ___Jt- 5* ( ipsi) X IQL~~~~~~~~~,, 5' (10psi) 6.....'Li —-7**i LU,I. i,,0 _________ 0 1.0 2.0 3.0 4.0 5.0 STRAIN,AL/Lo, % Figure 26. Stress Difference vs Strain.

96 In order to support earth-moving equipment, the moisture content of the sludge must not be high enough to prohibit compaction. The optimum content to produce maximum density is about 32 percent moisture on a dry-weight basis or 24.2 percent on a wet-weight basis. It has been shown elsewhere in this study (Table 19) that sludge with a moisture content on a wet-weight basis of 35-40 percent can be handled and worked with earth-moving equipment. Therefore one can reasonably expect to accomplish an improvement in permeability when the lime sludge is used as a core material in an embankment. The curves in Figure 26 showing stress difference vs strain are characteristic of curves for silt and soft clay rather than curves for dense sand and brittle clay. This is shown schematically in Figure 27. DENSE SAND OR BRITTLE CLAY / y LOOSE SAND, SILT OR SOFT CLAY STRAIN FROM LAMBE & WHITMAN (38) Figure 27. Typical Stress-Strain Relationship for Certain Materials.

97 * - 31% moisture **: 21% moisture ( ) confining pressure 9.0........... 8.0 (201psi 11** - 4* (30psi) y^, ~, 7.0 6** (20psi) 6.0. 35.0. " <0 l~yy >^ ^ - 17** (10psi) 1.0 _i i l. i i5 0 1.0 2.0 3.0 4.0 5.0 STRAIN, AL/Lo, % Figure 28. Load vs Strain.

98 As shown in Figure 26, the maximum stress is mobilized at a strain of ~2 percent, and failure occurs in a range of from 3 to 5 percent. Since the failure is a fracture-type failure and a definite fracture plane develops in each case, the lime sludge is shown to be much less plastic than a normally consolidated clay. As might be expected, the load vs strain relationship is improved by increasing the confining pressure. This is shown in Figure 28. Wu(69) shows that the failure angle in the triaxial test (a) is a = 45~ + E. Measurement of the failure plane of samples from the triaxial test in the present study shows a~60~, as shown in Figure 29. This suggests that the 0 of these samples should be in the order of 30~; they are 24~ and 28~. FAILURE 60~ PLANE Figure 29. Typical Failure Plane of Triaxial Test Specimen.

99 The bulk density of the wet sludge was determined on samples as taken from the lagoon by the tubular sampler: the results are given in Table 17. TABLE 17 BULK DENSITY OF LIME SLUDGE Bulk Sample Density (pcf) 1 90.4 2 98.0 3 95.0 4 96.5 The mean value is 95.0 pcf. On this basis the specific gravity of the wet sludge is 1.52. As mentioned elsewhere in the present study, the moisture content ranges from 44 percent to 54 percent on a wet-weight basis. Samples of the wet sludge as taken by the tubular sampler were analyzed for their volatile content as a measure of the amount of carbon and organics present. The results are given in Table 18. These findings identify the sludge as a relatively light-weight material, and one which contains very little in the way of organic material.

100 TABLE 18 VOLATILE CONTENT OF LIME SLUDGE Wt. of Wt. of Loss of Wet Dry Wt. at % Volatile Sample Sludge Sludge 600.C Dry Wt. No. (gm) (gm) (gm) Basis 1 129.58 78.40 4.58 5.85 3 124.07 73.47 4.55 6.20 4 116.52 65.99 4.46 6.75 9 126.05 75.67 5.01 6.60 Avg.6.35% X. ANALYSIS OF THE SLUDGE FABRIC In studying the physical characteristics of the lime/soda-ash sludge, it was deemed desirable to observe the shape and size of the particles comprising the sludge fabric. Since all indications were that most of the particles were less than.01 mm (10p) in size, an electron microscope had to be used. A JSM-U3 (Japan Electron Optic Laboratory, Inc.) scanning electron microscope was made available. The samples to be studied were mounted on a suitable support and coated in a vacuum with vapor-deposited chromium. During the scanning, an accelerating voltage of from 10-25 kv was used. Electron micrographs were made of the specimens at magnifications of 100X, 200X, 500X, 1000X, 2000X, 5000X, and 10,000X. Several stereoscopic pairs were used in studying the crystal structure in two dimensions. Typical examples of the electron micrographs are shown in Figures 30, 31, and 32.

101 (a) (b) 0x Manification (b) 500x Magnification _Nt - esM>x xs:X:'S:::fi,Xk.S::':'#"::: 9S.S:: ~~~~~~~~~~~~1w lo | 11_~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Cvl|_|-SEWS i!:S#;iS:;g:~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~:i 0 0 i:::::7:'>7#E.'::':'.:::~ ~~ ~ ~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.....

102 (a) (b) Figure 31: Electron Micrographs of Lime-Soda Ash Sludge (a) 2,000x Magnification (b) 5,000x Magnification (l1 shown to scale)

103 (a) (b) Figure 32: Electron Micrographs of Lime-Soda Ash Sludge (a) l0,OOOx Magnification (1p shown to scale) (b) 10,000x Magnification (lp shown to scale) l- - - - - - - - - - - -..... -- -............... I~~~~~~~~~~~...... I..I _ A 1 _ 1.. E | ~~~ ~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~.............. l l...._ _ l l l I _ |; _~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~................. =~~~~~~~~~~~~~~~...................................(..b...

104 Several observations can be made regarding these micrographs. The sludge particles are small, in the order of 2 to 3 microns, as shown on Figure 31 upon which a 1p scale has been drawn. The elemental analysis has conclusively shown that the sludge consists almost entirely (90+ percent) of CaCO3 (calcite), the crystalline shape of which is rhombohedral. In the micrographs that are of great enough magnification to show the structure of individual crystals, it is interesting to note that a distinct rhombohedral shape is in evidence throughout the mass of crystals. Some of the crystals have become rather rounded, having had their edges broken off. This is probably due at least partially to the manner in which they are handled during the water-softening process, being transported by sludge pumps through pipe lines at relatively high velocities. Moreover, these samples were derived from a sludge lagoon that was subjected to freezing and thawing, and that would also tend to round off some of the edges of the original crystals. It is also important to note that the crystals tend to be spherical rather than flat-plate in shape. This helps to explain the fact that the lime sludge behaves more like a silt than a clay, since silt particles tend to be spherical whereas clay particles tend to be shaped like flat plates.

105 XI. CONCLUSION As a result of this evaluation of the physical parameters of the line/soda-ash sludge, the following conclusions can be drawn. The material is made up of very small particles in the order of 2-5p that are generally spherical in shape. It is classified as low to very low in permeability, has a high void ratio, and is highly compressible. The addition of sand does not seem to influence permeability to any significant extent. The natural water content varies between 80 and 120 percent on a dry-weight basis, and between 44.5 and 54.5 percent on wet-weight basis. When dried, the sludge exhibits the property of not reacquiring its initial water content, probably due to physical property changes during oven drying. Because of the fine particle size, capillary action holds considerable water in the air-dried samples obtained under natural conditions. This means that considerable moisture will be present if the sludge is exposed at the surface of a landfill to reduce its dust potential. If the sludge is subjected to traffic, however, the structure of the material will be broken down and the fine particles will become quite dusty. Therefore, sludge should not be used as road surface material; it will become very dusty in dry weather and slippery in wet weather. But it will give no trouble if it is left at the surface in an area that is not subject to traffic.

106 The moisture content of the sludge must be at a reasonably low level if it is to be useful as a cover material on a landfill or if it is to be moved around the disposal site without trouble to the earth-moving equipment. Samples of sludge which were judged to be suitable for moving and working by the landfill operator were collected and analyzed for moisture content. The results are shown in Table 19. TABLE 19 MOISTURE CONTENT OF WORKABLE LIME SLUDGE Sample Moisture Content No. % of Wet Weight 1.3875 2.3904 3.3574 4.3887 5.3993 6.3845 From the findings reported in the literature and in this study, one concludes that if the moisture content of lime sludge can be reduced to 35-40 percent (on a wet-weight basis) by air drying or some other means, it can be (1) readily handled as cover material or (2) incorporated into the landfill without causing any trouble to the earthmoving equipment or undesirable conditions for other vehicles (trucks, etc.) that might pass over it. In this dry

107 condition, the sludge does not demonstrate any thixotropic properties, is not excessively slippery or slimy, and is not dusty, odorous, or in any way objectionable. If it should become wetter, it will again revert to a thixotropic material and become very sticky and slippery; this could cause trouble to trucks and tracked vehicles on the surface of the landfill.

108 CHAPTER 4 SOME PRACTICAL APPLICATIONS FOR THE SLUDGE AND METHODS OF HANDLING IT AT A LANDFILL As a result of this study, several practical suggestions can be made relative to the use and disposal of the lime/soda-ash sludge formed in the sludge lagoons of water treatment plants that use the lime-softening process. As shown in the work on high-iron-bearing solution in the present study, the sludge can be used beneficially by exploiting its acid-neutralizing potential. For example, the sludge might possibly be used to help improve the soil conditions of acidic coal-mine spoil. One study in which fly ash was used has already been conducted. (1) Lime sludge might well prove to be better than fly ash because metals which are toxic to plants (i.e., boron and manganese) are almost completely absent. No attempt has been made in the present study to determine the amount of lime sludge actually needed for improving acidic coal-mine spoil. However, on the basis of the available calcium present as calcium carbonate in lime/soda-ash sludge (as compared with the calcium present as calcium oxide in fly ash), the sludge would appear to possess much more neutralizing capacity. Fly ash is reported (1) to contain approximately 4% calcium oxide, whereas lime/soda-ash sludge contains at least 95% calcium carbonate. In order to provide neutralization to encourage the growth of grass, it was determined

109 that about 600 tons of fly ash per acre would have to be applied (plowed and harrowed with farm equipment, fertilized and seeded). As a control, pulverized limestone was applied to a plot at the rate of 8 tons per acre. Pulverized limestone can be assumed to contain approximately the same content of calcium carbonate as lime/soda-sludge; but since the sludge has a much smaller particle size, it would affect the soil more efficiently. The ratio of 8 to 600 tons per acre is roughly comparable to the calcium content of the two materials, indicating that the sludge would be much more efficient for this purpose. The rate of application of the sludge would be about 8 tons (dry solids) per acre. The impermeability and acid-neutralizing potential of the lime sludge might also make it useful as an impermeable lining for landfill sites that would otherwise be unsuitable due to porous soil conditions. Many state regulatory agencies are requiring that prospective landfill sites be modified so that the amount of leachate leaving the landfill is limited or eliminated completely. The use of clay or some other impermeable material is suggested for this purpose, and properly compacted lime sludge with the proper moisture content would be suitable. It is adequately impervious and also has the ability to remove iron and to neutralize any acid leachate that comes in contact with it. Because of its light weight ( 100 lbs./cu.ft.), the sludge is also suitable for use as a light-weight backfill. When it is properly compacted under controlled

110 moisture conditions, its settlement is not excessive and it has adequate supporting strength for many applications. The sludge is doubly satisfactory when used as backfill for concrete pipe in an aggressive soil, since it aids in protecting the concrete pipe against acid attack from the soil. When there is a possibility that acid leachate from a landfill will come into contact with a concrete structure, the sludge backfilled around the structure will protect the concrete against acid attack. As a part of this study field investigations were carried out on a refuse landfill in Rawsonville, Michigan, along with discussions with the operator. (23) Various methods of handling lime sludge were tried by the operator at this site to determine their feasibility. Excavation of the sludge was observed at two lagoons in the area as a basis for the time and motion studies conducted. When the Rawsonville landfill first began receiving the wet sludge, the trucks dumped it immediately in front of the slope of the active face of the fill. Because of its natural slump, the sludge was on the order of 2 to 3 feet deep. A bulldozer was used to push refuse over the sludge. This method proved unsatisfactory because the wet sludge was unable to support the weight of the refuse and bulldozer; under these pressures, it revealed its thixotropic properties and became very fluid. The sludge came up through the refuse and turned the whole mixture into a sticky, slimy, wholly unsuitable quagmire.

1ll Among the suitable methods for handling the wet sludge, one is to deposit the sludge in layers of from 6 to 12 inches, tailgating it from the truck. A bulldozer is then used to cover it over with a 2-foot layer of refuse. A refuse layer of this thickness has the capacity to absorb the fluidity of the sludge and prevents both the boiling through and the liquid conditions that are found with thicker layers of sludge. The beneficial characteristics of the sludge are best exploited by allowing it to air-dry to a moisture content of about 40% before using it in the landfill. This can be accomplished by spreading it out over a reasonably large area in rather shallow depths (2 feet or so); an even better method is to place it on a slope which will allow the moisture to drain out as well as evaporate. Under average summer weather and temperature conditions, about two weeks will suffice to reduce the moisture to the 40% figure that allows the sludge to be worked with conventional earthmoving equipment. At this moisture content, it has lost all its sticky and slimy characteristics. When dried to a moisture content of 40% or less, the sludge can be used as temporary (daily) cover in the landfill, which is stockpiled and used as needed. It contains no putrescrible material, has no odor or other nuisance-causing constituents, is fire-proof, and is impermeable enough to serve as a very adequate cover material. The sludge's small particle size may cause it to erode somewhat

112 more readily than a more granular material, and it will not be suitable for final cover because it does not have the ability to support vegetation. The sludge will become dusty if used on areas where traffic is concentrated, but not if it is used on areas where traffic is light. As excavated by dragline from the lagoon, the sludge contains at least 50% moisture. Sometimes large quantities must be disposed of in this condition, as when the lagoon is completely emptied in one operation and stockpiling for drying and later usage is impractical. In such case, the following method is suggested. As narrow a trench as possible (depending on the equipment available) should be dug in the original bottom of the landfill in an area to be covered with refuse. This trench should also be as deep as possible, without involving ground water, etc. Into such a trench, the sludge can be discharged directly from the open trucks and filled to the top. Then it is covered with refuse, which will have a kind of bridging effect over the trench. It is to encourage this bridging action that the trench should be kept as narrow as possible. The latter method is disadvantageous in that the beneficial attributes of the sludge are lost, and the cost of excavating the trench adds to the disposal cost of the sludge. Also, it may be difficult to find space for a trench large enough to accept all the sludge to be disposed.

113 The possibility of introducing the sludge to the landfill as a slurry has been considered. This method has been used to distribute the sludge onto the soil as a soil conditioner in correcting the pH of an acid soil. (13) For several reasons, however, this approach was not deemed feasible for applying the sludge to a refuse landfill. If the sludge is to be handled as a slurry, it must be fluidized and pumped out of the lagoon, and transported in a tank truck. Fluidization requires that it be mixed with water, an operation that usually requires the use of additional water. Because the sludge particles are more or less spherical in shape, their separation from the liquid tends to be comparatively rapid. This means that the sludge will tend to settle in the tank truck while in transit, adding to the difficulty of removing it from the truck. The transport of the additional water required to fluidize the sludge would add to the cost. Moreover, the additional moisture would not be desirable at the landfill because it would add to the leachate potential. Although the acidneutralizing capability of the sludge would remain effective with this method, most of its potential advantages as a cover material would go unrealized. This study considered the possibility of adding lime sludge as a soil conditioner to the kind of final clay cover material being used in the Rawsonville landfill. If successful, this would not only have helped in the disposal problem but would have produced a more favorable pH

114 condition in the clay, thereby improving its growth potential. Clay can be either acidic or basic; if lime is to be used to advantage, it must obviously be acidic. An analysis of the clay being used for cover at the Rawsonville landfill showed it to have a pH of 9.5, indicating that additional lime would hinder rather than promote the growth of vegetation. For any cover material that does have an acid condition, however, the lime sludge should be a valuable additive if it is spread and disked into the soil along with fertilizer and seed. CONCLUSIONS Based on the information gathered in this study the best method for handling the sludge in a refuse landfill is to first allow it to dry in a shallow pile (2 or 3 feet deep). When the moisture content has been reduced to approximately 40% it can be moved and spread in a layer 6 inches to 1 foot deep as daily cover or mixed with soil being used as cover material.

115 CHAPTER 5 COST ANALYSIS This chapter deals with a cost analysis of the various phases of removing lime/soda-ash sludge from a storage lagoon and incorporating it into a landfill for permanent disposal. The costs analyzed consist of: (1) Excavation from the lagoon by dragline. (2) Transport of the sludge by open dump truck. (3) Incorporation into the landfill by selected means. Cost data is very difficult to obtain relative to these operations. At best, they are generalizations which must be used with caution, due to variations in wage scales, weather conditions, traffic conditions, etc. The data presented here are derived from field observations where possible, and also from reference to the literature and from discussions with experienced persons. A time and motion study was carried out on a 2cu.yd. dragline while it was engaged in excavating lime sludge from a lagoon. In general, the dragline swung 1800 to empty its bucket, which was emptied in a shallow pile on a slope. A time breakdown for the operations (giving values as the averages of all the times gathered) is as follows: Time to fill dragline bucket - 12 seconds Time to swing 180~ with a full bucket - 15 seconds

116 Time to empty bucket - 3 seconds Time to swing 1800 with empty bucket and position for next fill - 18 seconds A total time for each bucket = 48 seconds The results of the study are given in Table 20. This particular dragline was hired at $45/hr., including operator and all other costs. On each filling, the bucket was observed to be about 3/4 full. If 90 percent availability is assumed for the dragline, then the cost for excavation under the outlined conditions is $.44/cu.yd. An estimate for dragline excavation was obtained from another excavation contractor (23) who estimated that the cost would range between $.45 and $.50 per cu.yd. using a 2-cu.yd. dragline. This compares very well with the calculated figure. A second time-motion study was conducted involving a 2-cu.yd. dragline which was engaged in excavating lime sludge from a lagoon and filling 20-cu.yd. open dump trucks for transport to a landfill disposal site. In general, the trucks were positioned so that they were parallel to the bucket, and the dragline swung 900 to empty its bucket into them. A time breakdown for the operations (giving values as the averages of all the times gathered) is as follows: Time to fill bucket 11.5 seconds Time to swing 900 with a full bucket 15.5 seconds to truck Time to empty bucket into truck 4.3 seconds

117 Table 20 Time Study of 2 cu. yd. Dragline (180~ degree swing to empty, discharge onto ground onto shz shallow pile on a slope) All times in hundredths of a minute. D = portion of time to fill bucket S1 = portion of time to swing to point of emptying E = portion of time to empty S2 = portion of time to swing back and position to begin to dig. D 20 20 22 10 18 17 20 20 14 25 22 30 S1 40 42 45 35 40 40 40 40 35 45 45 55 E 50 53 55 45 55 45 50 45 40 55 50 60 S2 80 74 80 70 80 75 80 73 70 100 100 90 D 20 20 25 15 20 28 25 20 20 20 25 20 S1 40 40 45 45 45 50 45 45 45 45 50 43 E 45 45 50 55 50 55 50 50 50 50 60 50 S2 80 80 80 80 75 90 80 80 75 80 85 75 D 20 22 25 20 20 15 23 14 10 15 23 20 S1 48 50 48 40 40 35 45 35 30 38 45 50 E 55 60 55 45 45 40 48 40 35 42 55 55 S2 80 93 80 70 70 65 75 65 65 70 84 85 D 23 25 20 30 25 15 15 25 30 30 25 S1 50 50 45 58 55 40 45 45 50 50 45 E 55 58 50 62 65 50 50 50 53 55 50 S2 80 80 75 90 100 75 80 90 85 85 80 Summation of Time = 37.54 minutes to produce 47 buckets, therefore it takes an average of.80 min. (48 sec) per bucket. Observations indicated that in this material the bucket was 3/4 full on the average which means that 114.18 cu.yd. of material can be excavated per hour. Assuming 90% availability, then, 102.76 cu.yd. per hour can be expected to be produced. At the rental rate of $45.00/hr. for machine and operator, excavation of the sludge costs $.44/cu.yd.

118 Time to swing empty bucket 90~ and 9.4 seconds position for next fill Total time for complete cycle 40.7 seconds The results of the study are given in Table 21. Transport times were measured over the 3-mile haul to the landfill and averaged 10 minutes. Positioning the truck at the landfill required one minute on the average; so did emptying the wet sludge out of the truck. The return trip to the sludge lagoon took 10 minutes at an average of about 20 miles per hour. If a 50-minute hour is assumed to allow for various nonproductive times, three loads are delivered every two hours. 3 loads @ 20 cu.yds./load = 60 cu.yds. Truck rental @ $20.68/hr. $41.36 for 60 cu.yds. Delivered 3 miles is $.69/cu.yd. or $.23/cu.yd./mile Analysis of the dragline costs in this case are not representative; since only three trucks were used and the time spent to load each truck averaged only 10 minutes, the dragline was unused about 50 percent of the time. If the cost of the dragline is included at the rate of $35.00/ hr., the total cost of excavating and of transporting the sludge three miles is $1.85/cu.yd. This could be reduced markedly if five trucks were used instead of three. A cost estimate from a construction contractor(23) for trucking this type of material was $.50 - $.70/cu.yd./ mile. Still another study(13) quotes trucking costs as averaging $.80/ton/mile, a figure that seems unrealistically high.

TABLE 21 TIME STUDY OF 2 -CU.YD. DRAGLINE LOADING TRUCKS (All values, minutes x 10-2) Avg. Avg. Seconds Dig 18 25 18 20 18 30 15 15 36 20 18 25 20 18 15 17 18 19.2 11.5 Swing Full Buck.et.to 27 25 22 25 27 25 20 25 29 25 22 30 30 30 25 23 22 25.4 15.5 Truck Empty 2 Cu. Yd. 5 10 5 5 5 10 5 5 5 10 7 10 5 7 10 8 10 7.2 4.3 into Truck Swing Empty Bucket & 10 15 15 15 10 15 15 20 15 13 20 15 20 15 10 22 20 15.6 9.4 Position__ — --- - Total Totale 60 75 60 65 60 80 55 65 65 68 73 80 75 70 60 70 70 67.7 40.7 Cycle Time..... —---.-. -- Average 10 buckets per load, excess not desired due to danger of spilling. Approximately 10 minutes to load a 20 cu. yd. truck, truck rental @$20.68/hr. including driver 10 minutes to drive 3 miles to landfill site 1 minute to position 1 minute to empty 10 minutes to drive to lagoon Approximately 32 minutes per round trip Assuming a 50 minute hour - 3- loads in two hours H% HD

120 Costs for placing the sludge on the landfill are (23) based on discussions with the landfill operator 23, and reflect his experience in working with the lime sludge. Using a bulldozer to spread the air-dried sludge (40 percent moisture) on the surface of the landfill in a thin layer costs approximately $.10/cu.yd. Dumping from open trucks over a bank in the landfill will cost approximately $.25/cu.yd. because upon drying, the sludge has to be moved to another location on the landfill where it is spread and compacted. Once the sludge has been spread on the surface of the landfill, disking is required to mix it with the other cover materials. That adds another $.02 to $.05/cu.yd. to the cost. Covering the wet sludge with separate earth cover is both unnecessary and expensive. Nothing about the sludge requires such cover; but if the operation is being contemplated anyway, it will cost from $.50 to $.60/cu.yd. This high cost is only for placing the earth cover; since earthmoving equipment cannot be operated over wet sludge at any depth, a dragline must be used to reach out over it. Instead of this approach, it is much more advisable to allow the sludge to drain and air-dry in a temporary location, and then use it for cover material. To develop costs for disposal of the lime sludge by different methods a general method of cost analysis was devised. It is outlined below.

121 The costs of excavation by dragline can be established by dividing the rental rate of the dragline (dollars/hr) by its production rate in terms of cubic yards per hour. Its production rate can be determined by time (48, 29) study or by reference to standard production tables. (489) Trucking costs can be analyzed by first selecting the truck capacity that is commensurate with the size of the dragline. Then the rental rate can be established by reference to a standard rental rate. (441) If the distance to be traveled and the average rate of travel are known, the time required to go to and from the loading and disposal points can be calculated. If the capacity of the dragline bucket is known, the time required to fill the truck and the time required to empty it can also be established either by time study or from standard tables. (48) This calculation will make it possible to determine the number of trucks needed to keep the dragline busy. Once the time and the size of the truck have been established, the cost of transporting the sludge to the disposal site can be determined (4,41) by reference to standard rental rates. 41) When sludge has been allowed to dry out (in low piles or on a slope) to a moisture content of approximately 40 percent, its handling at the disposal site can be analyzed as follows. A bulldozer is selected according to size, or the one in use at the site is made the basis for figuring the costs of handling. The production rate in this case is the amount of material (in cu.yd.) that the bulldozer

122 can spread from a pile in an hour. Average production rates can be obtained (29) by taking into account the fact that air-dried sludge is lighter in weight than ordinary soil. Rental rates are available for the particular machine being considered. (441) If the rate of production and the rental rate are known, it is possible to determine the cost/cu.yd. to spread the material on the landfill. It should be taken into account that the machine is already at the landfill site, and no provision need be made for bringing it to and from the site. There is always a possibility of removing the sludge from the lagoon by pumping and transporting it to a disposal site by tank truck. But problems arise due to the low moisture content of the sludge in the lagoon, which means that the sludge must somehow be fluidized in order to be pumped. Such a disposal procedure is not considered desirable on a landfill because of the excess moisture that is thereby introduced. Possibly this procedure might prove more suitable for disposal onto other sites such as farm land, yet attempts to implement it have not proven to be continuously successful. (17,55) An outline of the cost-analysis procedure for removal by pumping is provided, just in case this method is contemplated. A centrifugal pump of non-clog design capable of pumping against the existing head condition is selected and its rental cost determined. (4,41) This method requires some means of fluidizing the sludge, such as reversing the

123 direction of flow from the pump so that water is added to the sludge before it is pumped out of the lagoon. The pump selected should be such that it could be mounted with the tank, an arrangement that allows the same pump to be used both in loading the slurry and pumping it out onto the landdisposal site. The capacity of the tank should be selected bearing in mind its weight when full (a 15 percent slurry will weigh 2026 lb./cu.yd. or 10 lb./gal). The capacity of the pump and the size of the tank will determine how long it will take to fill the tank and empty it at its destination. (4) Rental rates for some types of tanks can be obtained. (4) Following are two typical cost analyses - for removing sludge from a storage lagoon by dragline and open truck, and for removing it by pumping and tank truck. Cost Analysis of Removal by Dragline and pen Truck Assumptions: Sludge contains 50 percent solids Dragline capacity, 2 cu.yd. Truck capacity, 12 cu.yd. Time to fill 6 min. (1 bucket/min) Time to disposal point 15 min. (5 miles @ 20 mph) Time to empty and return 14 min. Bulldozer at landfill is a D-6 Rental rates(4,41) Dragline $45/hr. including operator Trucks $12.50/hr. Bulldozer $22.50/hr.

124 Production rates 48'29) Dragline load 2 cu.yd./min Trucks 35 min/round trip 6 min to fill Dozer level 190 cutyd/hr Production and Cost Analysis: Dragline will produce 120 cu.yd./hr 50 min/hr 35 min/trip 1.43 trips/hr x 7 trucks x 12 cu.yd. truck =120 cu.yd./hr Dragline 4 = $.375/cu.yd. Trucks 712.50 = 730/cu.yd. 120 trucked 5 miles Dozer 22.50.$ 118/cu.yd. 190 $1.223/cu.yd. trucked 5 miles Cost Analysis of Removal by Pumping and Transport in a Tank Truck Assumptions: Sludge contains 15 percent solids Pump 450 gpm (130 cu.yd./hr.) Tank 4000 gal (20 cu.yd.) 10 min to fill tank 15 min to reach disposal site 10 min to empty tank 14 min to return to lagoon Total approx. 50 min for each trip Assume a 50-min hour: 1 trip per hour Rental Rates:(4,41,8) Pump $21.00/day Tank Truck $25.00/day

125 Cost Analysis: Pump 8 = $2.63/hr per 20 cu.yd. = $.135/cu.yd. Truck 5 = $3.12/hr per 20 cu.yd. $.156/cu.yd. $.291/cu.yd. (trucked 5 miles) In comparing these two calculations, it must be recognized that the slurry being pumped is assumed to contain only 15 percent solids, whereas the sludge being trucked is assumed to contain 50 percent solids. That makes it neces50 sary to increase the amount of sludge pumped by 5 or 3.33 times, which increases the cost accordingly: 3.33 x.291 = $.97/cu.yd. (transported 5 miles) The assumption in these figures is that no charge will be made for disposal of the sludge at the disposal site. Obviously, pumping sludge and handling it as a slurry is the most economical method. But for reasons stated earlier in this study, a slurry is not nearly as feasible for use on a landfill.

126 CHAPTER 6 SUMMARY AND CONCLUSIONS The results of the various analyses of the chemical characteristics of the lime/soda-ash sludge indicates that it consists of calcium carbonate (calcite) in excess of 90%. Very little other material is present; it consists of magnesium hydroxide, some silica, carbon and sulfur. In general, the sludge could be compared to a finely divided limestone. Several tests were conducted in which various solutions were put in contact with this sludge. The results showed that depending on the characteristic of the solution and the time of contact either equilibrium or steady state conditions can be expected to occur. With solutions of demineralized water equilibrium conditions will occur within 2 to 3 hours as indicated by the change in pH which leveled off at a value between 9 and 10. For leachate solutions of low mineral content, the pH at equilibrium will be 8 or above. Steady-state conditions develop with shorter time of contact and with higher mineral content in the leaching solution. This was indicated by the high-iron solution in contact with the sludge in the soxhlet apparatus. The pH of the effluent solution stabilized at 6+ from an original value of 406. Hardness and alkalinity will increase somewhat due to exposure to the lime sludge. If the leachate contains very low hardness to begin with an equilibrium

127 appears to be established with the hardness increasing in the order of 50 - 80 mg/j (as CaC03). When the sludge is in contact with a leaching solution containing a high concentration of iron, the results indicate that the sludge contributes to a large reduction in the amount of iron in the leachate. As stated in the text, this is due to multiple causes; they may be summarized as precipitation, oxidation, ionic attraction, and surface adsorption. An empirical expression for the removal of iron in an anaerobic environment by the finely divided lime sludge was developed: y = -4.1 +.0214 x, where y is the grams of finely divided dry sludge and x is the milligrams of iron as Fe++ removed. In connection with the removal of iron, the polarity and magnitude of the charge on the sludge particles were determined. The sludge has a positive charge, which helps to explain some of its effects in removing iron from solution. The rate of solution of the sludge in distilled water with a pH adjusted to a low pH (5.0) indicates that the sludge will go into solution very slowly and will remain in a landfill for a rather long time. The results of the analysis relative to the physical characteristics of the sludge show that the sludge consists of small (2p to 5r) spherical particles of rather high uniformity (x 100% passing a 200 mesh sieve); thus it would be classified as a silt-like material. It is rather light in weight with respect to most soils (specific gravity

128 of 2.35) and is quite alkaline, being composed largely of calcite (calcium carbonate) and having a pH of 10.1. The permeability of the sludge is in the range of 1 x 10 to 1 x 10-7 cm/sec, which places it in the general soil classification of "very low" permeability. It was observed that the permeability increases as the void ratio increases. A relationship of the type of the Kozeny-Carmen equation was formulated. This equation relates the permeability (k) and the void ratio (e), and is in the form k = C eM Value of C was found to be 7.65 x 10 8 and the value of M,3.70. The results of the consolidation test show the sludge to be highly compressible. This comes about due to the small particle size, the high initial void ratio, the high natural water content, and the large change in void ratio which occurs with loading. This will cause a considerable settlement in the sludge used as fill. However, the settlement will occur in a relatively short time after the sludge is put into place and loading is applied. If proper moisture and compaction are provided, very little settlement will occur. The optimum moisture corresponding to the maximum density of the sludge was determined to be 32% (on a dry-weight basis). This resulted in a density of 81 lb/cu.ft. The triaxial test on compacted material was used to evaluate the shear strength of the sludge. This evaluation showed that the sludge has an angle of internal friction

129 (4) of 28.6~ on the dry side of optimum moisture (21 percent), with a cohesion of 1.595 kg/cm. At approximately optimum moisture (31 percent) and with cohesion of 1.645 kg/cm2, the sludge has a (Q) of 24.30. These values should be reduced somewhat when applied to field conditions, since optimum moisture and density cannot then be achieved. But even so, the sludge shows favorable characteristics as a fill and embankment material. When used for embankment, the sludge must meet the stated moisture and density conditions (90 percent of maximum dry density). The fracture type of failure showed that the sludge is much less plastic than normally consolidated clay. There are several practical ways in which the sludge as excavated from a lagoon can be handled at a landfill. It can be spread in thin layers and covered with refuse immediately, or (preferably) it can be stored in a manner that will allow it to dry to a moisture content of 35 to 40 percent, after which it can be used as cover material or as an impervious barrier at the landfill site. Use of the dried sludge as cover material spread to a depth of 6 inches to 1 foot over the refuse and compacted with earth-moving equipment is recommended. If no further use is to be made of the lime sludge, it can be disposed of in a narrow trench. The lime sludge has potential for use as a means to neutralize acid soil conditions or acid leachates.

130 The costs of excavating and disposing of sludge at a landfill site were considered in this study. A reasonable estimate of costs for sludge removal by a dragline, transportation in open trucks, and bulldozer placement at the landfill is as follows: Excavation by 2 cu.yd. dragline $.45/cu.yd. Trucking in open truck $.25/cu.yd.mi. If trucks are emptied over a bank to allow sludge to dry, and sludge is to be rehandled $.25/cu.yd. If sludge is emptied in small piles to dry and needs only to be leveled and spread $.12/cu.yd. The total amounts to $.82 to $.95/cu.yd., transported 1 mile. (It should be emphasized that these costs apply only to a specific area and time (Michigan, 1972) and must be adjusted for other areas and times.) CONCLUSION On the basis of the research conducted and summarized in this chapter, the hypothesis outlined in Section I.B can be discussed and conclusions drawn. The characteristics of the lime/soda-ash sludge have been shown to be such that the sludge is highly impermeable and quite insoluble with respect to the normal flow of liquids over its surface. The effect of contact between the sludge and low-mineral-containing leachate with low pH is a moderate increase in the total hardness of the leachate (up

131 to the solubility of CaC03 55 mg/ ), and an increase in the pH to approximately 9-10. In general, these changes would not be considered to constitute pollution of either ground or surface waters. Contact between the sludge and high-iron-bearing solution with low pH has been shown to result in a neutralization of the acid condition in the solution accompanied by the precipitation of a considerable amount of the iron. Therefore the presence of the sludge might prove to be beneficial in a refuse landfill in which an iron-bearing leachate might occur; it would reduce the amount of iron in solution and would overcome any acid condition that prevailed. The same results are considered possible in other situations where a low pH, high-iron condition is likely to occur. Since the sludge is impermeable and can be landfilled when its moisture content has been reduced to approximately 40 percent, it can be used for lining landfill sites in which leachate might otherwise seep away through granular or porous material. The lime/soda-ash sludge contains no objectional substances which give rise to odors or attract flies or other vectors in any way. Both compactable and fire-resistant,it could serve as daily cover on a refuse landfill as long as its moisture content were low enough (40 percent) to allow it to be spread and compacted over the refuse. Since the sludge will become dusty if it is allowed to dry out and its structure is broken down, it should not be used in areas of continuous traffic.

132 The results of the consolidation tests and the drained triaxial tests show that the sludge can be used as a backfill material or in an embankment provided that the moisture conditions are controlled and good compaction is provided. Due to its light weight (81 lbs/cu.ft. at optimum moisture), it would serve well as a light-weight backfill and, if compacted thoroughly, would possess very satisfactory shear strength. (Compacted samples of sludge exhibit an average angle of internal friction of 26~ and a cohesion intercept of 1.6 kg/cm2 (1.6 tons/sq.ft.)) This is equivalent to an unconfined compressive strength of approximately 2.5 kg/cm2 (2.5 tons/sq.ft.). Stiff clay has an unconfined compressive strength of 1.00 - 2.00 tons/ft2, and very stiff clay an unconfined compressive strength of 2.00 - 4.00 tons/ft2 (38) When use of the sludge in an embankment was considered in the present study, the maximum height was developed using a safety factor of one (which is impending failure). Under actual conditions it is advisable to increase the safety factor because of uncertainty in the long-term cohesion of the sludge. Accordingly, the slope height should be reduced by requiring a safety factor of at least two. On this basis, the maximum permissible height of embankment which should be constructed using compacted sludge is about 115 ft. The side slopes should be limited to 26~ (1 ft. vertical to 2 ft. horizontal), which is approximately equal to the angle of internal friction. This includes an

133 additional safety factor of two, allowing for uncertainties due to the internal friction angle and seepage. In the absence of cohesion, seepage parallel to the slope will limit the allowable slope angle to approximately one-half the material's internal angle of friction. It has been shown that the sludge can be removed from storage lagoons by use of a dragline, and can be trucked in dump trucks to the disposal site without difficulty if the trucks have leakproof tail gates. The sludge can be spread to dry either in shallow piles or on a slope. When its moisture content has been reduced to 40 percent on a wet-weight basis, it can be moved and spread with a bulldozer over the surface of the landfill. It should be noted that prior to drying, the sludge as excavated from the lagoon is a very slippery, thixotropic material which is easily fluidized. Therefore it will not support any appreciable weight unless confined, and will cause trouble when tracked or other vehicles try to spread it or run over or through it. The cost of ultimate disposal of the sludge must be calculated in three phases: (1) excavation from the storage lagoon, (2) transportation to the disposal site and (3) final placement at the disposal site. A cost analysis of each phase indicates that it costs about $.40 to $.50/cu.yd. to excavate the sludge by dragline from the lagoon, and about $.10 to $.25/cu.yd. to handle and spread the sludge at the disposal site. The major portion of the

134 cost is in transporting the sludge to the disposal site. Trucking costs range from approximately $.25/cu.yd./mile based on observed data to $.50/cu.yd./mile based on responses from truckers. If the sludge is to be placed in a landfill, it is economic to transport the least possible amount of water. Based on the data gathered for this study, the overall cost for excavation and bulldozer placement in a landfill ranges from $.60 to $.75/cu.yd. With the addition of transportation costs, the total becomes $.85 to $1.00/cu.yd. transported one mile. Since these costs allow the volume in the sludgelagoon to be used over again, the economical feasibility of the operation becomes obvious. The alternative is to obtain a new sludge storage facility, which, since it will generally be more remote, will require not only a land investment but additional piping, etc. In conclusion, it can be said that the sludge removed from the lagoons used by the lime/soda-ash watersoftening-treatment plants can be disposed of in landfills economically and without causing environmental problems according to this study. It should be noted that the solutions used in this research did not contain any organic constituents so that the effect of lime on the organic compounds which are associated with landfill leachate is unknown. This aspect of the disposal of lime sludge into a refuse landfill as well as the effect of the lime on the biological activity within the landfill should be the basis for further research.

135 B IBLIOGRAPHY 1. Adams, L.M., Capp, J.P., Eisentrout, E., Reclamation of Acidic Coal-Mine Spoil with Fly Ash, U.S. Bureau of Mines Publication, Invest. Report 7504, April 1971, 29 pp. 2. Adrian, D.D., Nebiker, J.H., Source Control of Water Treatment Waste Solids, Report No. EVE 13-69-1 Univ. of Massachusetts, Amherst, Mass., 1969, 95 pp. 3. __, Standard Methods for the Examination of Water and Waste Water, 13th Ed., APHA, AWWA, WPCF, 1971. 4., Associated Equipment Dealers 1969 Rental Rates, 21st Ed. A.E.D., Oak Brook, Ill., 1970. 5., Bituminous Materials; Soils; Skid Resistance, ASTM Standards, Part 11, March 1969, 928 pp. 6. Apgar, M. A., Langmuir, D., "Ground-Water Pollution Potential of a Landfill Above the Water Table," Ground Water, Vol. 9, No. 6, 1971, p. 76. 7. Aultman, W.W., "Lime and Lime Soda Sludge Disposal," J.AWWA, 39:1211, 1947. 8. Bidwell, E.L., Univ. of Michigan, Dept. of Civil Engineering, Ann Arbor, Mich., Personal Communication. 9. Bishop, A.W., Henkel, D.J., The Measurement of Soil Properties in the Triaxial Test, Edw. Arnold & Co., London, 1964, 225 pp. 10. Black, A. P., "Disposal of Softening Plant Waste - Lime and Lime-Soda Sludge Disposal," J.AWWA, 41:819, 1949. 11. Black, A.P., Shuey, B.S., Fleming, P.J., "Recovery of Calcium and Magnesium Values from Lime-Soda Softening Sludges," J.AWWA, Vol. 63, No. 10, 1971, p. 616.

136 12. Black, C.A., ed., Methods of Soil Analysis, Parts 1 and 2 American Society of Agronomy, Series No. 9, 1965. 13. Burgess & Niple, Ltd., Waste Sludge and Filter WashWater Disposal from Water Softening Plants, Ohio Dept. of Health, Columbus, Ohio, 1969, 41 pp. 14., Effects of Refuse Dumps on Ground Water Quality, California Water Pollution Control Board, Publication No. 24, 1961, 108 pp. 15. _, Handbook of Chemistry and Physics 1971-72, The Chemical Rubber Co., Cleveland, Ohio, 1971. 16. Clark, E.E., Water Treatment Sludge Drying and Drainage on Sand Beds, Report No. EVE 24-70-4, Univ. of Massachusetts, Amherst, Mass., 1970, 179 pp. 17. Dittoe, W.H., "Disposal of Sludge at Water Purification and Softening Works of the Mahoning Valley Sanitary District, J.AWWA, 49:1351, Oct., 1933. 18. Emrich, G.H., Landon, R.A., "Generation of Leachate from Landfills and Its Subsurface Movement," Proceedings Annual Northeastern Regional AntiPollution Conference, Univ. of Rhode Island, 1968. 19. Faber, H.A., Klomp, K.C., et al, "Disposal of Wastes from Water Treatment Plants - Part 1," AWWA Research Foundation Report, J.AWWA, Vol. 61, No. 10, 1969, pp. 541-566. 20. Faber, H.A., Klomp, K.C., et al, "Disposal of Wastes from Water Treatment Plants - Part 2," AWWA Research Foundation Report, J.AWWA, Vol. 61, No. 11, 1969, pp. 619-638. 21. Faber, H.A., Klomp, K.C., et al, "Disposal of Wastes from Water Treatment Plants - Part 3," AWWA Research Foundation Report, J.AWWA, Vol. 61, No. 12, 1969, pp. 681-708. 22. Faber, H.A., Klomp, K.C., et al, "Disposal of Wastes from Water Treatment Plants - Part 4," AWWA Research Foundation Report, J.AWWA, Vol. 62, No. 1, 1970, pp. 63-70. 23. Ferrintino, M., Wayne Disposal Co., Rawsonville, Mich. Personal Communication.

137 24. Fleming, M. "Lime Sludge Becomes Fertilizer", American City, 72:102, Apr, 1967. 25. Gates, C.D., McDermott, R.F., "Characterization and Conditioning of Water Treatment Plant Sludge," J.AWWA, Vol. 60, No. 3, 1968, p. 331. 26. Gordon, C.W., "Calcining Sludge from a Water Softening Plant," J.AWWA, 36:1176, 1944. 27. Gray, D.H., Lin, Y-K., "The Engineering Properties of Compacted Fly Ash," Journ. of Soil Mechanics and Foundation Div., ASCE. 28. Gray, D.H., Penessis, C., "Engineering Properties of Compacted Sewage Sludge Ashes," Univ. of Michigan, Ann Arbor, Mich., 1971, 30 pp. 29. Havers, J.A., Stubbs, Jr., F.W., eds., Handbook of Heavy Construction, 2nd Ed., McGraw-Hill, New York, 1971. 30. Hem, J.D., "Some Aspects of Chemical Equilibrium in Ground Water," Proc. Symposium on Ground Water Contamination, USPHS, SEC Tech. Report No. W61-5, 1961, p. 20. 31. Howson, L.R., "Lagoon Disposal of Lime Sludge," J.AWWA, 53:1169, 1961. 32. Hudson, H.E., "How Serious is the Problem?", Waste Disposal from Water and Wastewater Treatment Processes, Proceedings 10th Sanitary Engineering Conference, Univ. of Illinois, Urbana, Ill., 1968, pp. 1-9. 33., Waste Disposal from Water and Wastewater Treatment Processes, Proceedings 10th Sanitary Engineering Conference, Dept. of Civil Engr., Univ. of Illinois, 1968. 34. Kaufman, W. J., "Inorganic Chemical Contamination of Ground Water," Proc. Symposium on Ground Water Contamination, USDHEW, PHS Tech. Report W61-5, 1961, pp. 43-49. 35. Kawamura, S., Tanaka, Y., "Applying Colloid Titration Techniques to Coagulant Dosage Control," Water and Sewage Works, 113:1966, p. 348. 36. Krasauskas, J.W. "Review of Sludge Disposal Practices," J.AWWA, Vol. 61, No. 5, 1969, pp. 225-230.

138 37. Lambe, T. W., Soil Testing for Engineers, John Wiley & Sons, June, 1951, p. 27. 38. Lambe, T. W., Whitman, R. V., Soil Mechanics, John Wiley & Sons, New York, 1969, 553 pp. 39. Mann, Jr., L., Applied Engineering Statistics for Practicing Engineers, Barnes & Noble, Inc., New York, 1970, 175 pp. 40. Mitchell, J. K., "The Fabric of Natural Clays and Its Relation to Engineering Properties," Soils Geology and Foundations, Highway Research Board Proceedings, Vol. 35, 1956, pp. 693-713. 41. Moselle, G., ed., National Construction Estimator, 18th Ed., Craftsman Book Co., Los Angeles, Calif., 1970-71. 42. Mulbarger, M. C., "Sludges and Brines Handling, Conditioning, Treatment and Disposal," Advance Waste Treatment Training Course, USFWPCA, SEC, 1967. 43., Tables for Conversion of X-Ray Diffraction Angles to Interplanar Spacing, National Bureau of Standards, Applied Mathematics Series 10, issued Sept. 20, 1950, Superintendent of Documents, Washington, D. C. 44., Design Manual, Soil Mechanics, Foundations and Earth Structures, Navy Dept. Bureau of Yards and Docks, Washington, D. C., NavDocks DM-7, 1962. 45. Nelson, F. G., "Recalcination of Water Softening Sludge," J.AWWA, 36:1178, 1944. 46., Modern X-Ray Analysis, Nuclear Diodes, Inc., Prairie View, Ill., 1970, 25 pp. 47. Pedersen, H. V., "Calcining Sludge from a Softening Plant," J.AWWA, 36:1170, 1944. 48. Peurifoy, R. L., Construction Planning Equipment and Methods, 2nd Ed., McGraw-Hill, New York, 1970. 49. __, 1971 Inorganic Index to the Powder Diffraction File, Powder Diffraction Standards Joint Committee, Swarthmore, Pa., 1971. 50. Proudfit, D. P., "Selection of Disposal Methods for Water Treatment Plant Wastes," J.AWWA, Vol. 60, Nc. 6, 1968, p. 674.

139 51. Qasein, S.R., Burchinal, J.C., "Leaching of Pollutants from Refuse Beds," Journ. Sanitary Engineering Div., ASCE, Vol. 96, No. SA1, Feb. 1970, p. 49. 52. Remson, I., Fungaroli, A.A., Lawrence, A.W., "Water Movement in an Unsaturated Sanitary Landfill," Journ. Sanitary Engineering Div., ASCE, Vol. 94, No. SA2, Apr. 1968, p. 307. 53. Richart, Jr., F. E., "Review of the Theories for Sand Drains," ASCE Transactions, Vol. 124, 1959, p. 709. 54. Russell, G. D., Russell, G. S., "The Disposal of Sludge from a Lime-Soda Softening Plant as Industrial Waste," Proc. Ninth Industrial Waste Conference, Purdue Univ., Series No. 87, May, 1954, p. 201. 55. Russelmann, H. B., "Characteristics of Water Treatment Plant Wastes," Proceedings 10th Sanitary Engineering Conference, Univ. of Illinois, Urbana, Ill., 1968, pp. 10-20. 56. Salvato, J.A., Wilkie, W.G., Mead, B.E., "Sanitary Landfill - Leaching Prevention and Control," J.WPCF, Vol. 43, No. 10, 1971, p. 2084. 57. Savage, E. S., "Disposal of Softening Plant Sludge Plaque Marion, Ind.," Water Works Engineering, 107:995, 1954. 58. Sheen, R.T., Lammers, H.R., "Recovery of Calcium Carbonate or Lime from Water Softening Sludge," J.AWWA, 36:1145, Nov. 1944. 59. Steiner, R.L., Fungaroli, A.A., "Analytical Procedures for Chemical Pollutants," Research Project on Pollution of Subsurface Water by Sanitary Landfill, Series 1, No. 8, Drexel Univ., 1968, 27 pp. 60. Suffitt, I.H., Schoenberger, R.J., Fungaroli, A.A., Effects of Glass Containers on Sanitary Landfills, Environmental Engineering and Science Publication, Drexel Univ., 1970. 61. Terzaghi, K., Peck, R.B., Soil Mechanics in Engineering Practice, John Wiley & Sons, New York, 1968. 62. Terzaghi, K., Theoretical Soil Mechanics, John Wiley & Sons, New York, 1943. 63. Timm, J. A., General Chemistry, McGraw-Hill Book Co., New York, 1944, p. 670.

140 64. _, Municipal Water Facilities Communities of 25,000 Population and Over, USPHS, DHEW, Washington, D. C., No. 661, 1964. 65. Waring, F. H., "Methods of Lime Softening Sludge Disposal," J.AWWA, Vol. 47, No. 2, 1955, p. 82. 66. Weber, Jr., W. J., "Chemical Equilibrium in Natural Waters," Univ. of Michigan, 1971, 37 pp. 67. Weber, Jr., W.J., Stumm, W., "Mechanism of Hydrogen Ion Buffering in Natural Waters," J.AWWA, Vol. 55, No. 12, 1963, p. 1553. 68. Weyl, P. K., "The Solution Kinetics of Calcite," Journ. of Geology, Vol. 66, March 1958, p. 163. 69. Wu, T. H., Soil Mechanics, Allyn and Bacon, Inc., Boston, 1966, 429 pp. 70. Yong, R.N., Warkentin, B.P., Introduction to Soil Behavior, Macmillan Co., New York, 1966, 451 pp. 71. Young, E. F., "Water Treatment Plant Sludge Disposal Practices in the United Kingdom," J.AWWA, Vol. 60, No. 6, 1968, p. 717.

APPENDICES

APPENDIX A ELEMENTAL ANALYSIS

141 APPENDIX A (CONT'D) ELEMENTAL ANALYSIS Figure 33. Two Typical Traces of Captured Photons from Electron Microprobe During Elemental Analysis of Sludge Samples.

APPENDIX A (CONT'D) ELEMENTAL ANALYSIS -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~A I I- co I I I IT" t I i -1: I I I I I I I I I E I I I I zv ~~ ~ ~ ~ C, QU ---- ) 4 II~OiCU I~ IL1 I I II I AI Ur + z~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -1 - --- a Z'r4 ~~~~~~~~~~~ a~~~~~~~~~~~~~~~~#0 v U) H ++ _~~~~ rl ITT1177 7111 r rmrIl r Irl-rr 1 Ir i r =-,v r- r rI iT i rri i- I Irrr rr i rL -rrr- I I I Im r I ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ T4,I J' L ~'' r L o!,,I I 3 I + += ------ -- i J v~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ — Fiu 3 4 Typical DifIat I Pat te I SdI gI ISample I ifaion11 I i O a)~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Q m'C1EI v~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ a,~~~~~~~~~~~~~~~~~~~~~ le 1 - R trl +I V~~~~~LII _ rl~~~~~~~~~~~~~~~~~~Ii f I I U. I I — I I I PI 11 7 lr I I II I I I I r r n h E ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ Ly(~~~~~~~Li PHIIUPO s tb c NSTRUM NT?4 N, NEW YOR1 MP, J12533. MADR I Figure 34. Typical Diffraction Pattern of Sludge Sample by X-Ray Diffraction.

APPENDIX B APPARATUS USED FOR EVALUATION OF CHEMICAL EFFECT

143 APPENDIX B (CONT'D) APPARATUS USED FOR EVALUATION OF CHEMICAL EFFECTS Figure 35. Apparatus Used for Evaluating the Effect of Leachate Flowing Over the Surface of Sludge.

144 APPENDIX B (CONT'D) APPARATUS USED FOR EVALUATION OF CHEMICAL EFFECTS Figure 36. Soxhlet Apparatus for Surface Contact of High Iron Containing Solution Showing One Unit Before Application of Solution and One After Several Liters Have Been Passed Over Sludge.

APPENDIX C PHYSICAL TESTING APPARATUS

145 APPENDIX C (CONT'D) PHYSICAL TESTING APPARATUS Figure 37. Karol-Warner Constant Stress Consolidation Apparatus with Sludge Specimen in Place.

146 APPENDIX C (CONT'D) PHYSICAL TESTING APPARATUS Figure 38. Geonor-AS Triaxial Test Apparatus with Specimen in Place.

147 APPENDIX C (CONT'D) PHYSICAL TESTING APPARATUS Figure 39. Triaxial Test Specimen at Failure Showing Method of Preparation and Type of Failure.

148 APPENDIX C (CONT'D) PHYSICAL TESTING APPARATUS Figure 40. Permeameters Used for Measuring Coefficient of Permeability (k).

APPENDIX C (CONT'D) PHYSICAL TESTING APPARATUS Figure 41. Permeameter with Sludge Sample Following Permeability Test. Note Consolidation Crack Near Base of Up-Flow Cylinder.

APPENDIX C (CONT'D) PHYSICAL TESTING APPARATUS i.... Figure 42. Permeameter Disassembled (Porous Stones Used Top and Bottom Not Shown).

APPENDIX D ATTERBERG LIMITS DATA

151 APPEHJDIX D (CONT'D) ATTERBERG LIMITS DATA JOI KAmEI BYty DATt, *H"el'.B LuICATE'., *UJ.rcr, LIQUTD PLfASTIC. LIMITS cU;Krt BORING NO. < — LIQU.* __ _ __Lr_ __ __ _ DETEf'kU.'.,ATTION NO. 2 3 4 5 NO. OF i)LO''} 2 I COJNTrAt.,T NO. __..?. (, WT. VET SOIL -t CG NT. (q)..),,.,,'::, WT DRY SOIL+CONI: C() 0/1. -.. -,, r?, WT WATER C() W____TER ]..I J., ____ WT. CONT/t.'INER (g) D,,t 5-. 5'0?, 3 3 WT. DRY SOIL (Cq) 1 7!z' __, 1 " WATER CONTI.W!T (C/o).. c (., 3 PLASTIC LIMIT_ E~TERMIN.^JTICN tNO. l I_ | 2. | 3YVisual Soil Descrintion CONTAINiER NO. 7 _,, WT. WET SOIL + COJT. C()'), -,.'?.. WT. DRY SOIL + CONT. C() __ __ WT WATER (g).3,,_4 WT. CONTAINER (g),, _^ WT. DRY SOIL Cq).8'' WVATER CON4TENT ( % j ______ FLOW' CURVE..O. _ -_ -. -...= 5 10 20 25 50 40 50 0,jNCER OF BLOW S RESULT SU)MtMY4ARY NATU.rAL C \'..' R I L,) PAUSTIC PLASTICIT Y L LI QUIDI' Y UIIF:ICL - CC. N1," L,.l I *.;iT IriE0X._ijf..J SSJFICATIO0 7i?.7 r |g

APPENDIX E DATA FOR DRY DENSITY VS. MOISTURE RELATIONSHIP

152 APPEINDI X E DATA'FOR DRY DENSITY VS. PMOISTU'JRE REL.ATIONSHIP JOB NAMF: Dur 1 {fj DATE: / 2 — / 5) SHEET: JOB LOCATtON-. sUULCCT:, tC; < j-4rc L_ CL It NT: COMPACTION METHOD_ __ MATERIAL r,.-_ _ IT- _ r /L; ) NO. OF LAYERS_..._ __ BLOW'S/LAYER2,2C SPECIFIC. GRAVITY.': 5 VOLLIUME OF HOLD. ___ _ DENSITY DETERMINATION Test No. i I z - ________ Mold and.Wet Soil (qm). I<C,.A.*.. y...?. _____ _ ______. Md *,.. _ -. Mold (gm) i)o 7. 7Z.._:7. -( 772.''427 72_ Wet Soil (gm) -.^,.0... 1.. _l.7 __________. Wet Density (gm/cnm3) 1, 4 /S. _, L7..._____ _ Dry Density (gm/cm3) /.25 /.25 /2,z? 7 L. Dry Density (pcf) 7_, o 71..S r6' 731^ __ WATE[R CONTENT DETERMINATION Can No. fO 1___ c __ _______ Wet Soil and Can (gn) L,!,C, 7.:. I 2 23: Dry Soil and Can (gcr).?.?. 8. 3,. 5<'_ Wt. of Water gin).4 /Z,4 b I Z,3 _______ Wt. of Can (gnm) _____.?1.'7 *. * ______ "_'~ ",Z.-' 2. L Wt. of Dry Soil (gin); _. ~. 2. 3?. Ij 7_________ Water Contenrt (%) _ 1,Z.4 _________ REMARKS:

APPENDIX F TYPICAL CONSOLIDATION TEST DATA

153 APPENDIX F (CONT'D) TYPICAL CONSOLIDATION TEST DATA ANALYSIS TIME: 7/-' TEST SER ES /0 i-IELD DATA LABORATORY DESC. APPARATUS &E-ASUREME-TS boR-4lG NO. 4/1Q / RNlmi ACuCHkT G, - 76 IZ SAMPLE No. _ ___ INC3 DIAMET E — N DEpTH ______________ RlG AR.-A A:'4 SQ INs E-LE VAT( O ___O De. cIpTIOM 6,< y RE&MARKS ____. DRY oENS5TY A e = 5OLIDS 4EICT (1CL3?J) -. - k - WAT&RR CONTSE —T ____Ck 5PE;CIMAN J LoCT ION TO P BOTTOM"T. s T e-t;-p_ CONTAINER NO. R. ___ R.N DI GREC- O SATURATIO, 0 WT. cONT- WET 5OIL (9).. ___. 8Z / _ ___1 START.__ iT. CONT + DRY 5OIL (9) _- /(______ -r D WT. WATER, Ww (g) _ /'.. 6.. WT. CON TAINER (9). /4.,6 /g q' - 8 WT. DR 50 L, Ws (9) ___7_. 77 377___ jWR CONTT O -%'TZ __ "'.' 1,T'____ 0 S J ZJ tz 0 F0rI TTCfI TM.- CoeF-. o- Co.SoL.: o ~ - = < 4S ^ ^ \I,I 2 | | L oc Cv (SQc/SAec) flo 4i MO;g cerN M6Too MoeT <a J5* ^^ 5 ^. N'C- f N 0__/___,__2___o_"~__ 0..... _ __.. o. o. z..._ o * o I.; I.' &2,.o./ z,lo~ql _,,o2 /., 2 1,6S,o 7.., /../,l3.. o....._______.. ___ 8g,/3/~,/I2^,_3_3___ _ _______, 3 s J/ _/G28_,o _t. 37___ _______,_. __. Z-so 3. 3^, <6. 3o __ ____L. bll..A.......:... Dbl.C. O...;AAL5S_.7..., O,,_. a ~tiJA.'-, R( l,.t(-, MA'?,, Itr-R.b t Il(.,ON AMALl.'.'IMF-_.

CONS=L GAGE-S &TTIMNG ETES5T SERIE:S jI I;'-FSSLIRZ- INCeE.~r;::, T A' R.., ~t-LAPS&..~CO?RA-SS.O AP$- D COQPKRSSIlCO rTItM,.,- t.,'VF DIAL. Rr~:A'G T~I.E- - t & DIAL D/ATE' T _i_,_t E"I ((M), ) (:7;..-s) DATE TI E -- (r,,) (', ).<c': —) I O 0________T.:i________ 0 0 -_____ DA________! __0.2 _5 0.5 0_____________ ________ ______i___, i _._'_ s t7I ___ _ __~_ ___ 00 30 1 _______ _______ I _ _ t I f t' H 0.I Z' 3 4 5 7 8 10. 1.0 0 )'.7., _ I __ HH O

CON'-L. C-GAGF- SETTIMG 3.4 T 5T 5&RIES & 10 PPE75S LJ ~ ~ ~~CrAPPLIE-D xa! l-slart" R E; M AF~M R Y,,-' R f. PR^SSURs. 1CR&M&NTAPPLIED $ S/-Efr1%&ARKS: ________________________ F^ort?irSsUE: Orh K&,ASQC__ LMAPS~ E COwiPRE5)I01 ONLAP5ED COrGMP2$SS1CIN TIME t VF DIAL RAD)NG TlIM& t D DIAL L D i DAIT r (M"T) (w7^T ) -.NC4S) DATE: T7 r ( (- (T1c s) O O t.0 J ~e ____ _ _ _ _ ____ __oZ F. j4_______ _ ____ _ ____' _____ _____ I _o__ 0.5_. 1104. ______________J.o1 2.0 4 ___j_ _____________ I______t________^ ____ ______ ____ I 2. 27 _____________ _ ______________ ___ ____.0~~; O ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 1 0 ________9._25 2.52 _________ _ ^ K _ _ _ _ J} } _ _ _ _ _ _ _ _ _ _ ____ j ____ ^.1 9. 1 _______ I________ ___i______ ______ 00 3.O ___ __t_ _ __ _ _ _ _ 1 2 2 5 2,. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ i_ 2 _9.00 3.0 -- _ 12 2i 5 331 _ _ _ _ _ _ i5 4_ _ _ _ _ - Z 1 I ____ \ 5.0 __ _ _ i ____ _ __ i _ j i ______U _! - 0 C>~~~~~~~~~~~~~~~ 5 I I "\\I I [111i lh; i7F~T " {' i I i I i; Z 1 H^^ _r ^Tit r n~ ftlll 1 N'ir f T~ o lt n'T - -~~~ i - i. ~ H t K~ ~ ~ ~ ~ ~~~~~~~~~! -I I I 111 [,, II __.1. 9A Z IC~rl~X * I'I::i I I _______ 1..1______! iiiLlui U... I,h^ I liL cu ~ ~ ~ ~ ~ ~ - I 1 I ~ iI ~~~~~~~ 0 4' 6 7 9 0 0.1 1-0.O ooooo 10000 h u, -t e Ln

CONBL,.-GAGE ST'TlNG 4. TS"T s:REs /, 4 PRU'5UR r INCZME NT APPLIED _ 9 -/-S. 2&MAR S;____________ -ROM 0?xRSSUR& Oh- 4CAQM ______________ f's.LA.PSt D CC ^ PK RCE-C55ION.'LAP5 ED CC MP? S:0 | TIME t DIAL PRAD1ING TIM t 1Ef DIAL RPAO'. EDAT T)1 ~- (t- )__) (J w,) (tNc-.s) DAT e T}rE (iM.-) (F7) (c^s) s i _ 0__________ ____ o______0.25.5 i___________________________ ____ ____ _ 2. _____;.III II!____ _______,,1 4.00 2.0. j. > __9_.oo 3.ooI5.Q01t< 1_ _ _ __,l S1 2 2 ____f2-25 3.5 |____ ____ -z. J L ____- _ h i______ Zo.03ojo 4.0.1 _______ _ ^ 7 - I___ I ____25 __ __ ___.5 L___ _I____ i ~ 1 25.oo 1 *-0 l t _ I | t i L > o H i _ I _ _ _ _ _ I I I I i i_____ > -..H-t O 2 3 4 5.0 6 7 0 10 1000 IjOO.: j * ) t I1 (;tU I -i-S )!

CONBS-L GAGE- SfTTIM 7, 4 T EST sRlEr: /: 4 p~L?PRSRSE I5:NCJPR - MT APPLUrt _b L- YSA R -CARM5 F-ROM PRESSURE: Of- _5 KG-, cC<2 I' C. ItLAPS~E COM1 P, 5510N ELAPS& D COM PRE L-SSON TI ME- t DIAL REAbDNG T;M t T AtAL Rt Ol A DATE- TIMrE- (MN) (r') (;sc-s) A': TIE - (r:) ( T' ) O(i.c T=s).... t O.. i...... f I 1 ol a.0f5 0-5 1._ ____ ____! 1 - 2 2__ ___ 2.5 2.5! ____ 6____ i 2 i o 9.00 3.o 0 3 __ 12.25 3.5,Zi _______ I!___~__0.oo 4.0, I ______ _____________ q t n I.,io j;.1 j X X 2 i i' 1l i i I I t t0 Z'~i -4ri t }I itMS Ij i.', i I Ii.l ti_ _.5,___.4. f...4...J._______________________.!^ —>^.f> - -i —4JU —...<.' i~b~' I: I!| il l I i ii ) */t" C/?^')t -(M-^tnes),,r tnI U 4~~~~~~~~~~~~~~~*~~~~~~ (Iif iI1:)Ii

CON3X L GA/ZE- 5TTM 7___ Th$T Se RI O S 4 PRE&SSURE- ICRfEcM M TAPLIS&D J 1LKCc/5QCm _ _REMARKS:_ ____ -Ro.M PU-rSSUfSU Of- )6 K/,5SQCm?___________________ t LEAP 5 F_ COR-,SlO4 ELAPS&ED Cc CCMPRBSSlON TIMe- t DIAL R~AIDTINX t Vt C1AL R ADlV1 DAT__E_ T1M - M(i.) M E r( r? ) (:CtcE-S)DATTE:. TIMEr (MI).1) (V 7 ) ( _______o01 W0 ^< _____________ _____j 1i. ____2__.[0.2 5.5 ________________________ _______. 0. 0._ _ _ C1 _ _____ ___15I ________2 I ____.J"____________________j- ______ _J ______94.00 2.0 i= _ I _ _ __________ to2 2. ______________________ j _________ _____!______I 9.o00 2.0 / ______ ______ _____ 6.295 2.5 _________'d _______ I_____\9. oo f4.0 -PS^ j _________ ________ ____ C0X z _______i__ _______ 02.25 _.5___ ______,______ ___________25..0 _________ _______________ _______ ____________ UC'T —---- I'ii i *ii — ^1 ~c,i. ifi fi nC ______ — -- -- -- _- 4.0______ _ _____ -- -_^.ih. t~ I ____. I HO _, _-___ Zo%________ _I1_4__43 L ~ 5 1 i T r | i i.!1 j~j i ~~ ~ ~ ~ ~ ~ i..coi _M — _ __ i 2lil:i-^-Li:L3t'^ t^ *r N - ^ ti 1! i 1I Th;ii ^~~~~~1.._ i____lLi!Ji _, j_ r 1 J'\ I I S 6 7 &10 o.1 l-o 1o.o too i1oo 100000'-p I I t k I - 1 7 1&S a~~~ ~ ~ ~ ~ I Io;r F r;i 1r ~~' 4 5 6 7~ 8 t. 10 0. 10 10 10 jOO 1C~ (fr4N~~~~~~ ) U,;iI~i ~~i

CONBEL GAGE S.ETTING _ -. Tt. &...S _o..? SSURsJ ISC^tE Nm-APPLU&D LL KS/s5aCH S MARKS: F orl.- PLRtSSUREr O- K CAsrt f-C. LA PS5ED COMPR-:5-5O ELA PS COMPRESS ON T1M- t F DIAL RADI.S3N TIME- t Vt DIAL RtAL'D)O DATr T} C- (E,~) (.4-t) (,.c;-_s) DATc TfE. (.,,) (,-F ) (~cu-:~) _ _ _ _ _ 1O_ _ _ __ _ _ _ 0_Z_ _ _ _ _ __._ __25 0_5 o __ I ___I I __ i s.oo ^.o!.j ~.oo i2.0, - ~ r ii ____ ___.2.5 2.5,0._________________ t- _ i _ _ _oo _ _. _ _ _ _ _ _ 1 _ _ _ _ 12.2$ 35 ____ ______. J.. I z. 1,- __ _ft_.o o,.i,.,......ao _ I.,~, _ _l_ I........ iL.__.. H t- u s ) */t',T l ~,,,..'1^5,,,,: j ^>li!!t~ ~ t l di,Z,..i i Z 4 6 7 0 0. (.' o; O I' 2. 5r 4- 51 & 7 8 ~ I O. I I.O to io oo, toO -'' - ~:- (, rA; l t )

APPENDIX G COMPUTER PRINTOUT OF ANALYSIS OF CONSOLIDATION TEST DATA

160 APPENDIX G (CONT'D) COMPUTER PRINTOUT OF ANALYSIS OF CONSOLIDATION TEST DATA LI,'E 0940 SAMPLF? 9A WEICHTS: Di{Y fSAMlLE, WPATEil? 39.0,50.0 NUM73ER OF L1OADINGS? 7 PRESSIUR,', DELTA Z, T90 TI50?., *.08)0, 1 96,. 50? 4,.-056.2 R9, * 0PO 8,.T)/100, 1 *.4,.*75 16,.0/478, 1.00-55? 32.0599 1.00*.45? 64*.0567s 1 *44,.50 TEST NUMBER 9A INITIAL CONDITIONS: MOISTURE CONTENT 128.9 X0F DRY WEIGHT SATURATION 112.6 % DRY DENSITY.639 GRAMS/CUCM APPLIED COEF OF CONSOLIDATION PERMEABILITY COEF PRESSURE VOID) (SQCM/SEC) (CM/SEC) (KG/SQCM) RATIO METHOD 1 METHOD 2 METHOD 1 METHOD 2 oOO 2.68.141 2.26 6.0E-03 5.5E-03 5.0E-06 4.6E-06.281 p.14 3.5E-03 2.9E-03 9.5E-07 8.0E-07 *562 1.95 6.3E-03 2.8E-03 1.4E-06 6.3E-07 1.125 I.72 7.8E-03 3.3E-03 1.1E6 4E-07 2.850.1/3 6.4E-03 3.3E-03 6.5E-07 3.3E-07 4.500 1.15 3.5E-03 2.4E-03 1.9E-07 1.3E-07

161 APPENDIX G (CONT'D) COMPUTER PRINTOUT OF ANALYSIS OF CONSOLIDATION TEST DATA SAMP E.? 10A WEIG HTS( D:);Y SAMPLFE, WATIR? 37.7,39.3 NUMBERi OF LOADINGS? 7 PRESSURE, DELTA z, T90, T50? 2.*1029, 1.69.50 /4,.*0274.00,. 90 8o *031 33.2,. 55 16,.0397 1.69./15? 32,.0525,2.25,.39 64,.0498, 1.46,.30 TEST NiUMBEH i 10A INITIAL CONDITIONS: MOISTURE CONTENT 104.2 %OF DRY WEIGHT SATURATION 87.4 % DRY DENSITY.618 GRAMS/CUCM APPLIED COEF OF CONSOLIDATION PE/RMEABILITY COEF PRESSU1R VOID (SOCM/SEC) (CM/SEC) (KG/SQCM) RATIO METHOD 1 METHOD 2 METHOD 1 METHOD 2 *000 2.80.141 2.29 6.8E-03 5*3E-03 7.OE-06 5.5E-06.281 2.15 2.4E-03 2.4E-03 7 1E-07 7.4E-07 *56AP 1.99 2.7E-03 3.6E-03 4.8E-07 6.6E-07 1 1~.5 l.8PO 45E-03 3.9E-03 5.5E-07 4.8E-07. 250 1 53 2.9E-03 3.8E-03 2.5E-07 3.4E-07 4.500 1.2.8 3.6E-03 4.1E-03 1 7E-07 1.9E-07

162 APPENDIX G (CONT'D) COMPUTER PRINTOUT OF ANALYSIS OP CONSOLIDATION TEST DATA SAMPLE? 1 1A WEIGHTS: DnY SAMPFLEJ WATE;? 56.1*39.8 NUMBER OF LOADINGS? 9 PRESSUiE, DELTA Z, T90 T750,.01477,. /9, 0? 4, *0080. *19, 0 8..0509,.30,0 16',.0156.20, I 5 3P, *0862P, t —-^0259,.16 13 64.,.0340, ~ 1 6,0? 16,-.00O26,o0?2,-.0040 0,0 TEST NUMBER 1 A INITIAL CONDITIONSS MOISTURE CONTENT 70.9 XOF DRY WEIGHT SATURATION 107.2 % DRY DENSITY.920 GRAMS/CUCM APPLIED COEF OF CONSOLIDATION PERMEABILITY COEF PRESSURE VOID (SQCM/SEC) (CM/SEC) (KG/SQCM) RATIO METHOD 1 METHOD 2 METHOD 1 METHOD 2.000 1.56 ~*1l 1.39 2.5E-02 1.2E-05.281 1.37 2.3E-02 1.9E-06 ~562 1 20 3.5E-0 9.3E-06 1.125 1.1/ 4.8E-02 1.5E-02 2.0E-06 6.3E-07 2. 50.06 5.6E-02 1.6E-02 2.0E-06 5.9E-07 4.500.94 5.0E-02 1.3E-06 1 125 *95 * 41f.97

163 APPENDIX G (CONT'D) COMPUTER PRINTOUT OF ANALYSIS OF CONSOLIDATION TEST DATA SAMPLE? PA WEIGH JTS DRY SAMPILE, WATER? 36 * 745. I NUMBER OF LOADINGS? 9 PRESSU.RE, I)E:LTA Z7 T90, TSO 7 2, ~.0807,.16,0 4, *0193,2.l5,./41? 8,.02/49,1.96,.36? 16, ~0337, 1.44,. 32? 32,.0472.81,.23? 64.0477,.49,.19 1 6-.0040OO0 2,-~0058,0,0 TEST NUMBER 12A INITIAL CONDITIONSi MOISTURE CONTENT 122r9 2OF DRY WEIGHT SATURATION 99.4 2 DRY DENSITY.602 GRAMS/CUCM APPLIED COEF OF CONSOLIDATION PERMEABILITY COEF PRESSURE VOID (SSQCM/SEC) (CM/SEC) (KG/SQCM) RATIO METHOD 1 METHOD 2 METHOD 1 METHOD 2 *000 2.91 141 2.49 7.4E-02 5.9E-05 281 2-.39 4.5E-03 5.8E-03 9.3E-07 1.2E-06 *562 2 26 4.9E-03 6.2E-03 6.7E-07 8.4E-07 1.125 2.09 6.1E-03 6.3E-03 5.9E-07 6.1E,07 P.250 1.85 9.4E-03 7.7E-03 6.8E-07 5.6E-07 4.500 1.0 1*3E-O2 7.8E-03 5. E-07 3.1 E-07 I 1.5 1. 62 *141 1.65

164 APPENDIX G (CONT'D) COMPUTER PRINTOUT OF ANALYSIS OF CONSOLIDATION TEST DATA SAMPLE? 13A WEIGHTS: DRY SAMPLE, WATER? 34.2,48.0 NUMR3ER OF LOADINGS? 9 PRESSURE, DELTA Z, T90, T50? 2,.0767 1.00,.30? 4,.0151,.00o*30? 8.0259,.49,.39? 16,.0457, 1 *69 20 7 32,.0066 1. 1.24? 64,.0561,.64*.17? 16,-.0033,0,0? 2,.0048 0,0 TEST NUMBER 13A INITIAL CONDITIONSt MOISTURE CONTENT 140*4 XOF DRY WEIGHT SATUiATION 103.3 % DRY DENSITY.561 GRAMS/CUCM APPLIED COEF OF CONSOLIDATION PERMEABILITY COEE PRESSURE VOID (SQCM/SEC) (CM/SEC) (KG/SQCM) RATIO METHOD 1 METHOD 2 METHOD I METHOD 2 *000 3.19 141 2.77 1.2E-02 9*2E-03 9.0E-06 6*9E-06 * 81 2.69 1 OE-02 8.1E-03 1.7E-06 1.3E-06 *562 2.54 2.0E-02 5.8E-03 2.8E-06 8.2E-07 1. 15 2.29 5.2E-03 1.0E-02 6.8E-07 1. 3E-06 P.250 1.96 6.0E-03 7.1E-03 5.7E-07 6.7E-07 4.500 1.65 9.2E-03 8.0E-03 4.5E-07 3.9E-07 I.125 1.66.141 1.64

165 APPENDIX G (CONT'D) COMPUTER PRINTOUT OF ANALYSIS OF CONSOLIDATION TEST DATA SAMPLE? 9A, 2)Y AND WEIGHTS DIY SAMPLE, WATEiR? 66.4,36.3 N(MBERP OFF LOADINGS? 9 PRESSITRW., DELTA Z, T90, T50 4, *00922, *I 6, 8,.0057 1.69.25 16*.0151,.64. 30? 32,.01/15, * 16, ~ 10? 64,.0151, 1.69. 1 5 1 6,-0031,0 0 2,-.0045,0 0 TEST NUMBEil 9A, PO %S SAND INITIAL CONDITIONSt MOISTURE CONTENT 54.7 XOF DRY WEIGHT SATURATION 110.9 DRY DENSITY 1 089 GRAMS/CUCM APPLIED COEF OF CONSOLIDATION PERMEABILITY COEF PRESSUIRE VOID (SQCM/SEC) (CM/SEC) (KG/S(oCM) RATIO METHOD 1 METHOD 2 METHOD I METHOD 2.000 1.16 * 141.1 3 1 3E-01 1 2E-05.2P1 1.13 8.0E-OP 1.7E-06.5602 1*11 7*5E-03 1.2E-02 2.0E-07 3.2E-07 1 125 1.07 1 9E-02 9.5E-03 7.OE-07 3.5E-07 2.250 1.03 7.4E-02 2.7E-02 1 3E-06 4.9E-07 4.500.98 6.7E-03.8E-0 6.4E-O0 1 7E-07 I.1P5.99 * 14 1.0

166 APPENDIX G (CONT'D) COMPUTER PRINTOUT OF ANALYSIS OF CONSOLIDATION TEST DATA SAMPLE? 10AO, 20% SAND WEIGHTS: DRY SAMPLES WATER? 5490,39 7 NUMBER OF LOADINGS? PRESSUlRE, DELTA Z, T90rO T50 2,.0363, *.64, * I 8 4*.0393., 1.O 30 8,.0216M", 1.14*~ 19 16,.0286. 56,.27??,.0018,0,0 8.0038. 0 0 TEST NUMBER 10A, 20% SAND INITIAL CONDIT.IONSt MOISTURE CONTENT 73.5 %OF DRY WEIGHT SATURAT I ON 1044 4 % DtRY DENSITY.885 GCAMS/CUCM APPLIED COEF OF CONSOLIDATION PERMEABILITY COEF PRESSURE VOI D (SQCM/SEC) (CM/SEC) (KC/SQCM) RATIO METHOD 1 METHOD 2 METHOD 1 METHOD 2.000 l.65 141 1.53 2.OE-02 1.6E-02 6.8E-06 5.6E-06 281 1 39 1IE-02 8.8E-03 /4 5E-06 3.5E-06.562 1.3f2 7o2E-03 1 3E-02 8.2E-07 1 4E,06 11eP5 1.2I 3.7E-03 82RE"03 2.9E-07 6.5E-07 2.250 1.09 1.4E-02 1.3 —02 7.2E-07 6.7E-07 ~562.07.141.07

167 APPENDIX G (CONT'D) COMPUTER PRINTOUT OF ANALYSIS OF CONSOLIDATION TEST DATA SAMPLE? 11A, 20 SAND WEIGHTS: D:IY SAMPLE, WATER? 56*6s39.6 NUMBER OF LOADINGS? 8 PRESSURE, DELTA Z, T90, T50 2.0504,.64, 15? 4,.*0106,.36,0,.0 1/f9,.z/l9,0 6,.0225,. 25,0? 32.08s 1.25,0 8,.0030,0,0 2. 0029,0,0 TEST NUMBER I A, 20% SAND INITIAL CONDITIONS: MOISTURE CONTENT 70.0 %OF DRY WEIGHT SATURTATION 107.3 % DRY DENSITY.928 GRAMS/CUCM APPLIED COEF OF CONSOLIDATION PERMEABILITY COEF PRESSURE VOID (SQCM/SEC) (CM/SEC) (KG/SQCM) RATIO METHOD 1 METHOD 2 METHOD 1 METHOD 2 000 1 ~53 *141 1.36 1.9E-02 1 9E-02 9.4E-06 9.3E-06.281 1.33 3.1E-OP 3*4E-06 *562 1.? 2.2E-02 1.7E-06 1.125 1.20 4*1E-02 2.5E-06 2.250 1I11 3*8E-02 l 5E-06 *562 1l10 ~141 1.09

168 APPENDIX G (CONT'D) COMPUTER PRINTOUT OF ANALYSIS OF CONSOLIDAT1ON TEST DATA SAMPLE? 1?A, 20% SAND WEIGHTS: DRY SAMPLE WATER? 58.1,37.4 NUMBER OF LOADINGS? 8 PRESSU;?:E DELTA Z, T90, T50? 2, 0331.25,0 4,.0062O.36, 0 S.*011 * 1 60 16.015 4, * 16 0? 32,?0205.16,0? 8,-0024,O,0?2,'.0018,0,0 TEST NUMBER 12A 2.0% SAND INITIAL CONDITIONS: MOISTURE CONTENT 64.4 %OF DRY WEIGHT SATURATION 103.1 % DRY DENSITY.952 GRAMS/CUCM APPLIED COEF OF CONSOLIDATION PERMEABILITY COEF PRESSUIE VOID (SQCM/SEC) (CM/SEC) (KG/SQCM) RATIO METHOD 1 METHOD 2 METHOD 1 METHOD 2 *000.47 * 41 1.36 5.OE-O0 1. 6E-05 ~281 1.34 3.3E-02 P2OE-06 *562 1 30 7.3E-02 4.OE-06 1l125 1.n5 7.OE-02 287E-06 2.250 1.19 6.7E-02 18E-06.562 1.19 *141 1.20

169 APPENDIX G (CONT'D) COMPUTER PRINTOUT OF ANALYSIS OF CONSOLIDATION TEST DATA SAMPLE?13A, 20% SAND WEIGHTS: DIY SAMPLE WATER? 53*.6S38-4 NUMBER OF LOADINGS? 9 PRESSURE, DiELTA Z, T90, T50? 2..00/8,. 360 ( 4a.0035, 25,.20? 8,.0058.~*1 6, 0? 16,.0103, * 16,0? 32s.0204, *.250? 64..02929. 16s-0? 16,.0030,0,0? 2* 0036,0,O TEST NUMBER 3A, 20% SAND INITIAL CONDITIONSt MOISTURFi CONTENT 71.6 %0F DRY WEIGHT SATURATION 100.5 X DRY DENSITY.879 GRAMS/CUCM APPLIED COEF OF CONSOLIDATION PERMEABILITY COEF PRESSURE VOID (SQCM/SEC) (CM/SEC) (KG/SQCM) RATIO METHOD I METHOD 2 METHOD 1 METHOD 2 000 1 *67 *141 1.66 3.6E-02 1.6E-06 *.281.65 5.2E-OS 1.5E-02 1.7E-06 5-OE-07.5662.6 8.OE-02 2.2E-06 1 125 1.59 7.8E-02 1-9E-06 P 250 1.52 4*.E-02 1.2E-06 4.500 I.41 7.0E-02 1.3E-06 1 1 5 1.40.141 1.39

170 APPENDIX G (CONT'D) COMPUTER PRINTOUT OF ANALYSIS OF CONSOLIDATION TEST DATA SAM?L E? 9A, 20% SAND-. —. —r40% SAND WEIGT TS: DniY SAtPitL.E, WATER767.2 33.0 NUMBE:R OF LOADINGS? 9 PRESSUi E, DELTA Z, T90O T50?, *0175, ~ 16,0 4,.0059,.1, O? 8,.0066,. 1,0 16,.0102 * I 6,0 32,.0170 * 160 64, 0240, 10,0 16, 0029,0,0 2.00122,0,0 TEST NU1MBER 9A, 240% SAND INITIAL CONDITIONS: MOISTURE CONTENT 49.1 ZOF DRY WEIGHT SATURATION 101.8 % DRY DENSITY 1.102 GRAMS/CUCM APPLIED COEF OF CONSOLIDATION PERMEABILITY COEF PRESSURE VOID (SQCM/SEC) (CM/SEC). (KG/SQCM) RATIO METHOD 1 METHOD 2 METHOD I METHOD 2 *000 1.13 *1/41 1.08 8.0E-02 1.3E-05.281 1.07 l.OE-01 5.9E-06 *562 1.05 1.0E-01 3.3E-06 1 125 1.02 7. 5E-02 1.9E-06 2.250.97 7.2E-02 1 5E-06 4.500.91 1.1E-01 17E-06 I1.125.90 *141.86

171 APPENDIX G (CONT'D) COMPUTER PRINTOUT OF ANALYSIS OF, CONSOLIDATION TEST DATA SAMPLE? 10A, /O'f ScAND WEIG;HTS DiY SAMPLE, W!ATEl? 54.9,38.7 NUMBER O)F L1ADINGS? 8 PRESSUIE, DELTA Z T90, T50 2, *07P*,?. *. 5 45? 4, *016/1 1.I 1,.35? 8S.02121.69,.30? 16.0288,.l 81 25 32,.0300, 81.18 8,-.0026,0,0 2, -0033,0,0 TEST NUMBER 10A, 40% SAND INITIAl, CONDITIONSt MOISTUlE CONTENT 70.5 XOF DRY WEIGHT SATtJIATI ON 102 8 X DRY DENSITY.900 GRAMS/CUCM APPLIED COEF OF CONSOLIDATION PERMEABILI TY COEF PRESSURE VOID (SQCM/SEC) (CM/SEC) (KG/SQCM) RATIO METHOD I METHOD 2 METHOD I METHOD 2 *000 1.61.141.36 5.3E-03 6.2E-03 3.8E-06 4 4E-06.281 1.31 8.7E-03 7.0E-03 1.5E-06 1.2E-06.562 1.23 5.9E-03 7.7E-03 6.7E-07 8.8E-07 1.125 1.13 1.1E-02 8.6E-03 9.2E-07 6.9E-07 2.250 1.03 1~OE-02 1E1-02 4*6E-07 4.8E-07 562 1.04.141 1.05

172 APPENDIX G (CONT'D) COMPUTER PRINTOUT OF ANALYSIS OF CONSOLIDATION TEST DATA SAMPIE? 11A, 40% SAND WE IG HTS: DIY SAtMLE. WATER? 59.1*37.7 NUMBERI OF LOADINGS? 8 PRESSURE, DELTA ZJ T90, T50 1620622.181,0 4,SATURA N 10506 60 8000 163.6/40 516 1018 -02 491 -0? 32. 0300 8 1 4902? 85 0026 0,0 4.0026,0,0 TEST NUMBER I 1 A 40% SAND INITIAL CONDITIONS: MOISTURE CONTENT 63.8 XOF DRY WEIGHT SATURATION 105.2 % DRY DENSITY.969 GRAMS/CUCM APPLIED COEF OF CONSOLIDATION PERMEAIBILITY COEF PRESSURE VOID (SQCM/SEC) (CM/SEC) (KG/SQCM) RATI O METHOD 1 METHOD 2 METHOD I METHOD 2 ~000 I.*43 *. 141 1.23 1.5E-02O 9. 1E-06 281 ~19 1 ~7E02 1 ~9E-06 *56P l1l/4 1.6E0.E-02 *4E06 1. 125 I 07 2.0E-02 1.~2E-06 2~ 50.98 1 ~9E'O2 7*9E-07 * 562.97 ~ 141 *96

173 APPENDIX G (CONT'D) COMPUTER PRINTOUT OF ANALYSIS OF CONSOLIDATION TEST DATA SAMPLE? 12A 40% SANT) WEIGHTS DRY SAMPLEs WATER? 61 5,35.6 NUMBER OF LOADINGS? 8 PRESSURE, DELTA Z, T90s T50 2,J 0586, 1 69J.30 4,.0089,2.?.25 *50 8,.0157, -,81 1 8 16,.01 87,.49,0 32,.0222s.25,0 8, -.0024, 0 2,-.002S60, 0 TEST NUMRER 12A, 40% SAND INITIAL CONDITIONS: MOISTURE CONTENT 57.9 %OF DRY WEIGHT SATURATION 102. % DRY DENSITY 1.008 GRAMS/CUCM APPLIED COEF OF CONSOLIDATION PERMEABILITY COEF PRESSURE VOID (SQCM/SEC) (CM/SEC) (KG/SoCM) RATIO METHOD 1 METHOD 2 METHOD 1 METHOD 2 *000 1.33.141 1.15 7.2E-03 9.4E-03 4.1E-06 5.4E-06.281 1.12 4.9E-03 5.1E-03 4.5E-07 4.7E-07.562 1.08 1.3E-02 1.4E-02 1. E-06 1.1E-06 1.125 1.0? 2.1E-02 I.OE-06 2.250.95 38E-02 1 2E-06.562 *96 ~141.97

174 APPENDIX G (CONT'D) COMPUTER PRINTOUT OF ANALYSIS OF CONSOLIDATION TEST DATA SAMPLE? 13A, 40% SAND WEIGHTS: DRY SAMPLE, WATER? 40-5,144- 1 NUMBER OF LOADINGS? 8 PRESSURE, DELTA Z, T90' T50? 2,.0345, 1 69,.25? 4s.0275, I.O00.35? 8,.0192,.81,.25 16,.0543,/4.00 32,.0654, 1 0,.*40 8,.0026,0,0? 2,.0030,0,0 TEST NUMBER- 13A, 40% SAND INITIAL CONDITIONS: MOISTURE CONTENT 108.9 XOF DRY WEIGHT SATURATION 100.8 % DRY DENSITY.664 GRAMS/CUCM APPLIED COEF OF CONSOLIDATION PERMEABILITY COEF PRESSURE VOID (SQCM/SEC) (CM/SEC) (KG/SQCM) RATIO METHOD 1 METHOD 2 METHOD 1 METHOD 2 *000 2.54 141 2.38 7*4E-03 1.2E-02 2.5E-06 3.9E-06 * 81 2.25 1 2E-02 7.7E-03 3.2E-06 2.1E-06 *562 2.16 1 3E-02 1.OE-02 1.3E-06 1 OE-06 1.25 1.91 2*4E-03 3.6E-07 2.250 1.60 8.OE-03 4.6E-03 7.8E-07 4.6E-07 *562 1.59 141 1.58

175 APPENDIX G COMPUTER PRINTOUT OF ANALYSIS OF CONSOLIDATION TEST DATA 90 DIM ASC203 100 PRINT "SAMPLE"I 110 INPUT AS 120 PRINT "WEIGHTS I DRY SAMPLE, WATER"t 130 INPUT Gl.G2 135 PRINT "NUMBER OF LOADINGS"J 136 INPUT N 140 PRINT "PRESSURE. DELTA Z, T907 T50" 150 FOR J"2 TO N 160 INPUT PCJ3,DCJ3,TCJ3]UCJ] 170 NEXT J 300 LET PCl]"ZO 310 LET VIl3.1.6*.76*2.54001 390 LET V2-Gl/2.35 330 LET EC13w(V -V2)/V2 340 LET S"G2/(V1-V2)*100 350 LET G3-Gl/Vl 360 PRINT 365 PRINT USING 600,AS 366 PRINT 370 PRINT USING 610.G2/GI*100 371 PRINT USING 611,S 372 PRINT USING 612*G3 373 PRINT 380 PRINT USING 640 381 PRINT USING 650 382 PRINT USING 660 383 PRINT USING 670 384 PRINT 400 FOR JS2 TO N 405 LET PC J3PCJ3*.4536/2.54001/2.54001 410 LET Z"Z+DtJ] 420 LET V3"31.6*Z*2.54001 430 LET ECJ](V1t-V2-V3)/V2 440 LET H C.76-Z+DCJ3/2)*2.54001 445 IF TCJ3<.05 THEN 455 450 LET BCJ3".R48*Ht2/4T/T CJ/60 455 IF UCJ]<.05 THEN 470 460 LET CCJ3]. 197*Ht2/4/UCJ3/60 470 LET KCJ3](ECJ- l -ECJ )/(PCJ-PCJ-13) 478 LET KCJ3*KCJ3/C(EC(J- 1/2+ECJ3/8) 473 IF UCJ3]<05 THEN 475 474 LET LCJ3]KCJJ*CCJ)*.001 475 IF TCJ3].05 THEN 490 480 LET KC(J"KCJ]*DCJ3*.OOl 490 NEXT J 00 PRINT USING 700 PCI EC 1 510 FOR JgS TO N 51l IF TCJ]4.05 AND UCJ]3<05 THEN 517 51 I IF TC43.O05 THEN 519 513 IF UCJ3<.01 THEN 521 514 GOTO 523 517 PRINT USING 700,PCJIECJ3 518 GOTO 530 519 PRINT USING 720*PCJ3]ECJ],CCJ3,LCJ3 520 GOTO 530 5$1 PRINT USING 730,PCJ]3ECJI3BCJ3]KCJ2 58 GOTO 530 523 PRINT USING 710.PCJ]ECJIt,BCJ3,CCJ3,KCJ32LCJ3 530 NEXT J 35 PRINT 536 PRINT 537 PRINT $40 OOTO 100 600 ITEST NUMBER dd9 dfl#id99#Iid 610 I INITIAL CONDITIONS$ MOISTURE CONTENT 0I0*. 0OF DRY WEIGHT 611 SATURATION 19. * X 618 I DRY DENSITY d.9#0 GRAMS/CUCM 640 tAPPLIED COEF OF CONSOLIDATION PERMEABILITY COEt 650 IPRESSURE VOID (SQCM/SEC) (CM/SEC) 660 (KG/SQCM) RATIO METHOD I METHOD 2 METHOD I METHOD 8 67 0 f..-m....................... -........... -............ -- - 670 9*9 710 t.9.D99 D D 1 9' 9 9 710 *I 1.td1 dd d ll I I I DedIDII I eledtgIII ddDl III 7O0 9.999 9DI9 9.9Ittg 9i99l 800 EIN

APPENDIX H CALCULATIONS FOR CONSOLIDATION OF LAYERED SYSTEMS BY NUMERICAL METHOD

176 APPENDIX H CALCULATIONS FOR CONSOLIDATION OF LAYERED SYSTEMS BY NUMERICAL METHOD The theory and assumptions used in this method are stated in the text. Application of the method is to be shown here. Each layer is 12 inches of sludge H = 1/2 total thickness of sludge C = 1.93 x 10~2 ft2/hr v Yb = bouyant weight of sludge = 24 pcf t = 24 hours C x t24 =.019 x 24 =.456 T = CE.12A- =nAT n.456 v H2 v H2AT 2T' AT = A (AC) A = 1/2 C = z H Z = depth to point in question H = thickness of one drainage layer A~ ATv 1/2.125 1/4.03125 1/3.0555 1/5.02 1/6.0139

177 APPENDIX H CALCULATIONS FOR CONSOLIDATION OF LAYERED SYSTEMS BY NUMERICAL METHOD n/l day Layer H A =1/4 AC=1/2 A|=1/6 A|=1/3 A-=l/5 ___(ft) I.5 59 14.7 II 1.0 14.7 3.65 III 1.5 3.65 IV 2.0 3.65 V 2.5 3.65 VI 3.0 3.65.9 Surcharge 3.0 3.65.9 PORE PRESSURE COMPUTATIONS (PSF) FOR LAYER NO. 1 (See Figure 43) AT =.03125 AT =.125 AT -AT- -ATv v V n= 0 1 2 2 6 5 6 7.4 14.7 0 0 0 0 0 0 0 3 3 3 1.13 6 6 6 1.93 1.36.85.05 II'' 1' 9 9 9 2.73 I 12 12 12 2.73 1.93 1.20.08 15 15 15 2.73 18 18 12 1.93 1.36.85.05 21 9 9 1.13 0 0 0 0 0 0 0 0

178 APPENDIX H CALCULATIONS FOR CONSOLIDATION OF LAYERED SYSTEMS BY NUMERICAL METHOD PORE PRESSURE COMPUTATIONS (PSF) FOR LAYERS NO. I and II (See Figure 43 ) AT =.03125 AT =.125 V V n = 0 1 8 3 3.7 4..,0.... O O. - a 6 6 4.7 Hr 12 12 8.8 6.55 5.2 4.6 18 18 11.8 II 24 21.02 13.1 9.20 7.3 6.55 24.05 24.04 12.5 24.08 24.05 9.6 6.55 5.2 4.6 24.05 12.04 5.3 O 0 0 0 0 O 0 PORE PRESSURE COMPUTATIONS (PSF) FOR LAYERS NO. I, II and III (See Figure 43) AT =.0555 V n= 0 1 _3 _ 3.7_ l...... O.. O O 0 0 0 0 Lu III J12 12 9.9 9.1 II 24 20.6 17.6 16.0 s: II 29.2 27.6. 20.7 19.2 31.3 29.2 19.7 17.6 I I29.2 15.6 10.8 10.1 0 ______ 0 0

179 APPENDIX H CALCULATIONS FOR CONSOLIDATION OF LAYERED SYSTEMS BY NUMERICAL METHOD PORE PRESSURE COMPUTATIONS (PSF) FOR LAYERS I, II, III and IV (See Figure 44) T =.03125 n= 0 1 3.7 0.... 0 0 IV 12 12 10.5 N 2 24 22.5 20.3 33.1 32.0 28.0 i III ___ 40.0 38.2 32.5 43.2 40.8 32.1 41.6 38.6 25.8 34.1 20.8 14.7 0 0 PORE PRESSURE COMPUTATIONS (PSF) FOR LAYERS I, II, III, IV and V (See Figure 45) T =.02 n= 0 ___ 1.8 3.7 O, O,.,O -- --- 0 0 0 n V 12 11.7 11.2 sN 24 23.0 22.0 I IV 34.5 33.3 31.5 IV 44.3 42.4 39.7 I 52.0 49.0 45.2 III 56.5 52.2 46.1 I 56.1 51.2 43.4 II 49.8 40.7 32.4 I 38.7 23.9 18.6 O.., O..

180 APPENDIX H CALCULATIONS FOR CONSOLIDATION OF LAYERED SYSTEMS BY NUMERICAL METHOD PORE PRESSURE COMPUTATIONS (PSF) FOR LAYERS I, II, III, IV, V AND VI (See Figure 46 ) AT =.0139 n = 0 1.8 3.7 0 0 0 V.[2 _. 11. 8 11.6 o 2 4 22.8 23.0 35.2 34.4 33. 7 V - — __-. _ __ 46.1 45.0 43.7 55.8. 54.0 52.2 IV _... 64.0 61.6 59.1 69.7 66.1 62.3 71.2 66.6 61.1 68.0 62.6 55.0 57.8 48.4 41.3 42.9 27.9 22.7 0 0 PORE PRESSURE COMPUTATIONS (PSF) FOR LAYERS I, II, III, IV, V and VI PLUS 100 psf SURCHARGE (See Figure 47) AT.0139 AT =.0555 V____ V n = 0__ 6 2.5 19 28 0 0 0 0 0 VI 111.( A 42.0 Co __123. 0 76.0 63 6 1.6 n 133.7 109.0 143.7 126.0 110.5 10.4 2.8 IV 152.2 142.0 ___ 159.1 145.0 129.5 12..1 3.2 III 162.3 146.5 161.1 132.0 113.5 10.4 2.8 3.55.0 117.5 I 1 - _ * *. A A... 14.L3 832.0 66.0 6.0 1.6 T.2., __ _ I 122.7, 4.s_.. 0 0

181 APPENDIX H CALCULATIONS FOR CONSOLIDATION OF LAYERED SYSTEMS BY NUMERICAL METHOD TABLE 22 CONSOLIDATION BY LAYERS* eA = x 2H; e = 2.80; H 0.5' 1+e 0 0 Avg. Pore Pressure avg_2 e A Layer psf Kg/cm (Figure 20) Ae (inches) VI 109.055 2.43.37 1.17 V 127.8.064 2.41.39 1.23 IV 148.8.074 2.39.41 1.29 III 172.8.086 2.37.43 1.30 II 199.8.100 2.34.46 1.45 I 229.0.115 2.31.49 1.55 = 8.05" NOTE: This consolidation takes place at the end of the sixth day assuming that the placing of the surcharge at the end of the sixth day takes zero time. * All six layers plus 100 psf surcharge.

182 APPENDIX H CALCULATIONS FOR CONSOLIDATION OF LAYERED SYSTEMS BY NUMERICAL METHOD N TIME 0 1/2 DAY 1 DAY 0 20 40 0 20 40 20 D PORE PRESSURE (psf) FIRST - 1 FOOT LAYER - SETTLED ONE DAY SECOND - FOOT LAYER ADDED AT END OF ONE.DAY - SETTLED ONE DAY co II 0 20 40 0 20 40 0 20 PORE PRESSURE (psf) TIIRND - 1 FOOT LAYER ADDED AT END OF SECOND LiAY - SETTLED ONE DAY Figure 43. Pore Prossurl-e Profi.e's (1, 2, 3 - 1 Foo:; Layers of Sludge) (1, 2, 3 - 1 Foot: Laiyers of Sludge)

TIME 0. 1 /2 DAY I i DAY IV'~~ V \' \ I t-*~~~~~~~00 r F u- - — essur Prof ie - \ ---- II - 1 F oot LAYER f S D I — S E _/ _I)__Y O H | 0 20 40 60 0 20 40 60 0 20 40 60 (5 f PORE PRESSURE'(psf) H FOURTH - 1 FOOT LAYER ADDED AT END OF THIRD DAY H - SETTLED ONE DAY O h Figure 44. Pore Pressure Profile (4 - 1 Foot Layers of Sludge) Co Laj

j TIiE 0 12 HOURS I 24 HOURS V ~! I l l'. it, 1 V i' S I I I I FIFH 1 FOOT LAYER ADED AT TE END OF FOUR t ___..Figure 45. Pore Pressure P_ i t (5 - 1 Foot Layers of Sludge) f-~~~i 0~~ OH~s - i III s i \ ~ I \ \ i en 0 20 40 60 0 20 40 60 0 20 40 60 t O PORE PRESSURE (psf) FIFTH - 1 FOOT LAYER ADDED AT THE END OF FOURTH DAY Figure 45. Pore Pressure Profile Co

N. - TIMEO0 ( El 12 HOURS 2 3OURS | ~ ~ ~ ~ XJ iv i I ia i'\ 12 i J!!! i i ~ I \;s! n i_ _____i__i __!! _ _ _ _ N:_ _______ ~3 a ^,~~ ~ ~ ~ ~I C) I C) a ~ i!. 1 i I j \ t **. \' \a " ^' IIZ''' l f t i i i 1- *? -M.!' |i a _ I I. *!; _ I _ ~ ~ ~ ~ ~ ~~~~~~~~~~~~~~c HH — \ —--— \ —-I LLJ —-— __ - _________^-______________ f~~~~~~~~~~~~fT! J^"I \^^; ^ * i i o u ff 20 40 60 800 20 40 60 0 40 60 PORE PRESSURE (psf) SIXTH - 1 FOOT LAYER ADDED AT END OF FIFTH DAY - SETTL ED ONE DAY Figure 46. Pore Pressure Profile (6 - 1 Foot Layers of Sludge) I ~i tn r~~~~~~~~~~~~~~~~~~~~III O~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0;i t~~~~~ ~~~L

'' I DAYS,'! I X *::' - S C..Li.. T!~I T ~VI:; ~ ~_ __ __ _,\ I __, j,_ c:I -| i j _____ 2 I_'__ Q i I PSF S 0 _., SI^^ _ L 1 _ - \ _S_____ _f;'^ * j 1!' * 1!'? l i ^ ~ C Z I o. j I i /' f! tj1 Figure 47. Pore Pressure Pro) (100 psf Surcharge) 0o o%~

APPENDIX I SAMPLE DATA AND COMPUTATIONS FROM TRIAXIAL TEST

187 APPENDIX I (CONT'D) SAMPLE DATA AND COMPUTATIONS FROM TRIAXIAL TEST 2 Sample #4 Diam = 3.32 cm, Length = 8.30 cm, Area = 8.65 cm 31% Moisture, 30 psi Confining Pressure Diff. (p) Dial AL/Lo A/(1 - AL/Lo) Load Load AG1 = P/A L (Strain) (Strain) Dial (kg) (Stress).02.024 8.659 60 3.120.360.05.06 8.662 115 5.98.69.10.12 8.667 195 10.14 1.17.15.181 8.673 250 13.00 1.499.20.241 8.678 320 16.64 1.918.25.30 8.683 370 19.240 2.216.30.36 8.688 415 21.580 2.484.35.422 8.694 467 24.284 2.793.40.482 8.699 515 26.780 3.079.45.542 8.704 560 29.120 3.346.50.602 8.709 600 31.200 3.582.55.663 8.715 640 33.28 3.82.60.72 8.72 680 35.36 4.055.65.78 8.725 715 37.18 4.26.70.84 8.73 750 39.00 4.47.75.90 8.74 790 41.08 4.70.80.96 8.74 820 42.64 4.88.85 1.02 8.75 852 44.30 5.06.90 1.08 8.75 882 45.86 5.24.95 1.145 8.76 910 47.32 5.40 1.00 1.21 8.76 937 48.72 5.56 1.05 1.27 8.77 962 50.02 5.71 1.10 1.32 8.77 988 51.38 5.86 1.15 1.40 8.78 1017 52.88 6.02 1.20 1.45 8.78 1035 53.82 6.13 1.25 1.51 8.79 1060 55.12 6.27 1.30 1.57 8.795 1084 56.37 6.41

188 APPENDIX I (CONT'D) SAMPLE DATA AND COMPUTATIONS FROM TRIAXIAL TEST Sample #4 Diam = 3.32 cm, Length = 8.30 cm, Area = 8.65 cm 31% Moisture, 30 psi Confining Pressure Diff. (p) Dial AL/L A/(1 - AL/L ) Load Load AG1 - P/A L (Strain) (Strain) Dial (kg) (Stress) 1.40 1.69 8.81 1122 58.34 6.63 1.45 1.75 8.81 1140 59.28 6.73 1.55 1.87 8.82 1160 60.32 6.84 1.60 1.93 8.83 1175 61.10 6.92 1.65 1.99 8.83 1200 62.40 7.07 1.70 2.05 8.84 1213 62.56 7.08 1.75 2.11 8.84 1225 63.70 7.20 1.80 2.17 8.85 1238 64.38 7.28 1.85 2.23 8.85 1253 65.16 7.36 1.90 2.29 8.86 1265 65.78 7.42 1.95 2.35 8.86 1280 66.56 7.51 2.00 2.41 8.87 1290 67.08 7.56 2.05 2.47 8.88 1302 67.70 7.63 2.10 2.53 8.88 1310 68.12 7.67 2.15 2.59 8.89 1320 68.64 7.72 2.20 2.65 8.89 1328 69.06 7.76 2.25 2.71 8.90 1335 69.42 7.80 2.30 2.77 8.90 1344 69.89 7.85 2.35 2.83 8.91 1350 70.20 7.88 2.40 2.89 8.92 1360 70.72 7.93 2.45 2.95 8.92 1368 71.14 7.98 2.50 3.01 8.93 1375 71.50 8.01 2.55 3.07 8.93 1382 71.86 8.05 2.60 3.13 8.94 1388 72.18 8.08 2.65 3.19 8.94 1397 72.64 8.12 2.70 3.25 8.95 1404 73.01 8.16

189 APPENDIX I (CONT'D) SAMPLE DATA AND COMPUTATIONS FROM TRIAXIAL TEST SAMPLE #4 Diam = 3.32 cm, Length = 8.30 cm, Area = 8.65 cm 31% Moisture, 30 psi Confining Pressure Diff. (p) Dial AL/Lo A/(1 - AL/Lo) Load Load ACi = P/A L (Strain) (Strain) Dial (kg) (Stress) 2.75 3.31 8.95 1410 73.32 8.19 2.80 3.37 8.96 1415 73.58 8.21 2.90 3.49 8.97 1425 74.10 8.26 2.95 3.55 8.98 1432 74.46 8.30 3.00 3.61 8.98 1437 74.72 8.32 3.05 3.68 8.99 1443 75.04 8.35 3.10 3.74 8.99 1446 75.19 8.36 3.15 3.795 9.00 1448 75.30 8.37 3.20 3.86 9.00 1450 75.40 8.37 3.25 3.92 9.01 1450 75.40 8.37 3.30 3.97 9.02 1450 75.40 8.36

VITA

190 VITA Eugene Andrus Glysson was born on August 16, 1926, in Montpelier, Vermont. He was graduated from Lamoille Central Academy in Hyde Park, Vermont, June, 1944. In September, 1944 he entered the University of Vermont in the Civil Engineering curriculum. He was called into the United States Navy in December, 1944, and served in the U. S. Navy until August, 1946. In September, 1946, he returned to the University of Vermont and completed his undergraduate work in June, 1949, with a Bachelor of Science in Civil Engineering. After graduation he was employed as a civil engineer in the Vermont State Highway Department and served as Assistant to the District Highway Commissioner, in District 5 of that department. In January, 1950, he entered the University of Michigan in the Horace H. Rackham School of Graduate Studies in the Sanitary Engineering graduate program; and in February, 1951, received the Master of Science in Sanitary Engineering. In February, 1951, he was appointed Instructor in the Civil Engineering Department of the University of Michigan; was promoted to Assistant Professor in July, 1955; and Associate Professor in July 1962. During his tenure at the University of Michigan, he has been involved with teaching and research in the field of water supply, waste water treatment, and solid waste

191 engineering. He has held the position of Director of the Rocky Mountain Field Station, during the years 1959-63, and was Director of the Solid Waste Engineering Training Program in the Civil Engineering Department, 1966-71. In September, 1968 he requested and was granted a sabbatical leave to attend Drexel University for a calendar year during which time he fulfilled the residence requirement for the Ph.D. in the Environmental Engineering and Science Program. Mr. Glysson is a Registered Professional Engineer and has served as consultant to various public and private agencies. He is currently Project Manager of the Solid Waste Management Study for Washtenaw County, Michigan and has served as a consultant to the U. So Bureau of Solid Waste Management Operations of the Environmental Protection Agency, and the World Health Organization. Also, Mr. Glysson is the author of several papers in environmental engineering and solid waste technology, and holds membership in Sigma Xi, Chi Epsilon, Phi Kappa Phi, honoary societies.