<TEXT N="B01035380"> <BODY> <DIV1> <P><PB REF="00000001.tif" SEQ="00000001" RES="600dpi" FMT="TIFF6.0" FTR="TPG" CNF="775" N="1"> USE OF CHLORIDE OF LIM0E AND LIQUID CHLORINE AS STERILIZING AGENTS, HISTORICAhL DEVELOPMENT:- Although chlorine is one of the most widely distributed elements, yet its discovery is of relatively recent date. The fL-mous Swedish chemist, Scheele, is given credit for its discovery* It is a heavy gas. pf green color, -and of very corrosive properties. It attacks violently xreta.l and organic bTodies. It is soluble in water and gfives a greenish solution of irritating smell, a.nd soon deaoi.oposes, especially when exposed to light. The gca-s ca.nb;:el,Iiiuified,by compressing it in special machines, airid i s;ikAep-t -and transported in strong steel cylinders ard has be-eo:'iLe?:] E m,rcial article. The bleaching' power>.Tf -th'. *ggaCs a.ttracted first attention to its use. Prior to.th is most of the linen wras sent to Holland and Fla nders where&'a highly profi table but conservative bleaching industry flourished, based on a fini cs'ing process in which ther use of buttermiilk seemed indispensable. The first use of chlorina (as a blea.ching ag-nt resulted in the rotting of the linen. But this defect was remedied by neutralizing the obnoxious properties of the gas by absorbing it first into a solution of alkali. Soda v-as used at first but i7as expensive,:ind after twelve years of labor Dr. Henry succeeded in substituting milk of liume, thus converting the powerful chlorine gas into a dry, portable, handy form containing 35^ of efficient chlorine. By combinring it with slaked lime, "chloride of lime" was formed. This is also known as "Bleach" ".Bleaching Powder" </P> <P><PB REF="00000002.tif" SEQ="00000002" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000002"> </P> <P><PB REF="00000003.tif" SEQ="00000003" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="815" N="2"> 2 "Hypochlorite of Lime", etc. The industrial use of a#loride of lime dates from the year 1800. An interesting comparison of the amount manufactured and the price per ton i s given by Mactear as follo s:1799 - 1800 52 tons @ $680o00 per ton 180o 147 " @ 54550 i 1820 333 " 29200o 182 910 " 131 00 " 1870 925 " 41,50 The production of chlorine was of necessity linked to th e soda industry, or Leblane process, since the initial raw miaterial, common salt or sodiuk chloride, is the same for both, The greatest development of the production of chloride of lime dates from the introduction of the British Alkali Act about 1865, when the so da manufacturers wiere compelled to cease discharginog large volumes of hydrochloric acid vapors into the air, or condensed acid into the streams. The available outlet for this bothersome by-product was the manufacture of chloride of lime; hence the development of a market for i it use. From this act to prevent a nuisance has grown up an industry which now gives u: not only a material for bleaching paper and textiles, but also a disinfectant and deodorizing agent, During the early years of its development a large portion of the hydrochloric acid had to be wasted, as the market for chloride of lime was much more limited than the demand for alkali so About this time a new method for making soda,from salt and ammnonia, known as the Solvay processwas foundo In this process no chlorine was given off with which to form chloride of lime a, a by-product. For this reason the old Leblanc </P> <P><PB REF="00000004.tif" SEQ="00000004" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000004"> </P> <P><PB REF="00000005.tif" SEQ="00000005" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="842" N="3"> 3 process was able to hold its own due to the ever growing demand for chloride of lime. But in 1890 a new rival entered the race. The first K1 electrolytic works, for the electric production of alkali and chlorine was installed in Frankfort, Germany. By this process soditum chloride was split into its constituents, sodium and chlorine. The sodium uniting with the water foxms caustic soda. The chlorine is used for various purposes, It is either liquified and transported in steel cylinders, or combined with slaked lime, forming chloride of lime. This is packed in barrels or steel drums, and generally contains from 30% to 405 available chlorine. USE OF CHLORIDE OF LIMlE:- This new process developed very rapidly not only in Germany but in other countries more especially in the United States. In 1912 it was estimated that more than 30,000 electric horsepower were used daily in its production. In 1912 the world's production of chloride of lime approximated 400,000 metric tons. The statistics for 1910 show the following production:Great Britain 110,000 metric tons, Germany 90,000 United States 80,000 "o France and Belgiuwn 40000 " Aus trai, Italy, Spain 30 000 t " Russia 22,000 " " The United States started making Chlorife of lime in 1895, and the following table will illustrate the development: </P> <P><PB REF="00000006.tif" SEQ="00000006" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000006"> </P> <P><PB REF="00000007.tif" SEQ="00000007" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="816" N="4"> 4 UNITED STATES IMPORTS AND PRODUCTION OF CHLORIDE OF LIME2 (metric tons) Year Imports Production 1850 2,810 1855 4,5 60 1860 7,850 1865 10,500 1870 1o,50oo 1875 22,000 1880 34,000 1885 43,300 1890 45,100 1895 45, 600 1900 01, 0 10,000 1905 43,600 17,800 1910 42, 600 81,000 Calciumx oxychloride, Ca 0 C12, is generally accepted to be the essential constituent of dry chloride of lime, and to undergo in contact with water, the following change:2 Ca 0 C12 Ca ( $ C )2 t Ca C12 calcium oxychloride: calciun hypochlorite + calcium chloride Chloride of lime is soluble in about twenty times its weight of water, leaving a small insoluble residue, mostly calcium hydrat(o In an aqueous bibution, calcium hypochlorite forms the only valuable constituent, the calcium chloride being inert and valueless. In its industrial application of bleaching, deodorizing, or disinfection, chloride of lime does not act by its chlorine, but by its oxygen. Its action is rot "hhlorination" bu t"oi dati on" Chloride of lime is valued and sold on its percentage of "available chlorine", a term which indicates the whole amount of free chlorine that becomes available in decomposing chloride of lime by means of strong acid. Half </P> <P><PB REF="00000008.tif" SEQ="00000008" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000008"> </P> <P><PB REF="00000009.tif" SEQ="00000009" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="831" N="5"> of the available chlorine is derived from the calcium hypochlorite, and half from the hydrochloric acid employed either as such or generated from the calcium chloride thru action of another strong acid' In keeping and storing chloride of lime the factors to guard against are carbonic acid, moisture, light and heatO Therefore it should be kept in closed veosels, and in a dry cool place. Lunge ( Sulphuris Acid and Alkali, Vol 3, p.642) gives two typical analyses of commercial chloride of lime which may be of interest as follows:Available chlorine 37,00 % 38 30 % Chlorine as chlorides 0,35 0 59 Chlorine as chlorates 0.*25 0.08 Lime 44.49 43 34 Iron oxide 0o 05 0.04iw: Magnesia 0,40 0.31 1 umi na 0.43 0.41 Carbon dioxide 0,18 0,31 Silica, etc. 0,40 0.30 Water and loss 16.45 16. 3 100 00 100 00 The fact that the available chlorine or hypochlorate is quite easily soluble, even in fairly cold water, and the undissolved sludge of hydrated lime, silica, etc., settles readily makes it possible to obtain clear colutions of chloride of limes for a constant feed in water or sewage purification, A few simple rules should be observed: First, aco not mix too stiff a paste, otherwise a gelatinizing action takes place and greater difficulty is settling is encountered. Never mix a paste with less than one-half gallon of water for one pound of chloride of lime. Second, it is not necessary or desirable to grind or </P> <P><PB REF="00000010.tif" SEQ="00000010" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000010"> </P> <P><PB REF="00000011.tif" SEQ="00000011" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="846" N="6"> 6 brea)k up the lumps too thoroughly; the available chlorine nearly all dissolves readily and too much agitation is detrimental to prompt settling. A- stock solution of chloride of lime containing approximately 2% available chlorine may be prepared as follOws:Three hundred pounds qpf commercial chloride of lime ( 35% available chlorine) equals lo5 pounds of available chlorine, assuming a recovery of 160 pounds of this free from sludge. These 100 pounds must be contained in 600 gallons to give a clear standard 2% slution* Due allovwance must be made for proper washing of the sludge, it thus contains in addition to the suspended lime and silica, a solution of equal strength to that of the clear liquid. The amount of sludge ise equivalent to about 1 gallon $or each 5 lbs. of chloride of lime used, Various forms of apparatus may be used. The essential parts are illustrated in Figs, 1, 2, and 3. This apparatus is an emergency outfit used by the State Board of Health at Monroe, Michigan during the Typhoid Fever epidemic of 1915. It consists of a mixing barrel, two storage barrels, and a dosing box. The hypochlorite solution was mixed in the upper barrel, and after time was allowed for settlement, the cleard liquid was drarwn off into one of the storage barrels below, thru a pipp placed far enough aheve the bottom of the mixing barrel to avoid drawing off any of the settled sludge. The amount of dose applied was regulated by hand control of a small pet-cock thru which the soluL.tion flowed from the dosing box, The dosing box was fed from two storage barrels in turn and a </P> <P><PB REF="00000012.tif" SEQ="00000012" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000012"> </P> <P><PB REF="00000013.tif" SEQ="00000013" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="126" N="7"> Hfed)CY //YPoeHi-oftra zDoil,,Y6 AppH^S~rUS.5 BY 7H',e 5-r.crfe B ol4s fHa9TH.. s.. >.. k. v.: a:. g: x s~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~s s s.;...........3...s..s........ i;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~;i II ls: 1.... I Ii llllllllllijijiljijil: I.......................... /gs1 ri:................................................................................; 0 0 t00 ffffff t0000 tS~tSSS: 0 f; ff t00: t? 0 0 ff f~t 0 0 t0 0: 0: f ft t 0:: C:0000S'St00000 f0000 ff ff DDS f........24 0;fX 0 0 fff 0;; 0.............;; ~ sz~ I mxIergenS>.y I-yp ilesllte:AppItuS<:0:: i-i-iri~i~i~i-i 0BoN: forX:; eis -te 9.. ~~~::-: _ —-—:-:: -:_-:: —:i-i~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~ ~~~ ~~~ ~~~~~~~~~~~~~~~~~~~~~~..............................................................................................:::::::::....... -.......................... - X -...........::: iii~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~i: I~~~~............................. ~~~~~~~~~~~:~~~~~~~:::::a::::3;1:1::~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~~~~~~~.............. ~~~~~~~~~~~~::::i:~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.....................................i~,iiiii i~~i' ~lii~i:; I:::~~~~~~~~~~~~~~~~~~:: ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 0::i 11~~~~~~~~~~~~~~~~~~~~...... Itlllllllllll~~~~~~~~~~~~~~~~~~~~~~l~~~l'i-Ij-j- l~~~~~~~~~~~~~~~~~ii~~~~~~i~~~j-jj~~~~~~~~~j~~~j ii:\~~........:j::::::~ ~~ ~~ ~~ ~~ ~~ ~~~ ~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~..........:::::::::I ~:::~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~......... ~~~~lii~~~~~~~~~~l~~~~~~~~~~~ "::::::::::::::jj:~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.......:i,,e:,:: _r: sii i~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~...............................:::r:::::::::::::::::::::::::::::::::::::::::f I11 iii~~~~~~~~~~~~~~~~~....................................~~~~~~~~~~~~~~~I j:::-~~~~~~~~~~~~~~~~~....... i~~~d~~P~~~k~~B~~X- -:) I-l-ll-ll'iiiiiiiiR~~~~~~~~~~~~~~~~~~~~~~~~~~i~~:~~d~~~i ~ ~............:::::t:E _:: —-— i_-:_ —:;i'iii~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~iiiiti_::::i~~~~~~~~~~~~~~~......... ~~::::::::::::::::::::::::::::::::::P:~~~~~~~~~~~~~~~~~~~::::::::::::::::::::::::::::::::::;~:::::::~~~~~~~~~~~~~~~~~~~~~~~:::................................... ~~~~~~::::::::::::::::::~ ~~ ~~ ~~ ~~ ~~ ~ ~~ ~ ~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.................. t -a~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.......::: ii:].I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~lii~~~~~~~~~~~::~~~~~~~~~::~~~~~~~~~:~~~~~~.~~~~~~.~~~~~~~~~~:Q-..............: -- --- -- -: ------—:'-: --::: - -:- -::- - -: --::: —-:: -: -- -- - - -..............:: -:::::::: I::-::::::::: _: -::'~ ~ ~~~~~~.................. ~ ~ ~ ~ ~ ~ d.~:3 </P> <P><PB REF="00000014.tif" SEQ="00000014" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000014"> </P> <P><PB REF="00000015.tif" SEQ="00000015" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="845" N="8"> 7 constant head of solution in it was miintained by a ballcock. By knowing the ratio of pumping, it was an easy matter to aajust the pet-cock so any desired ratio of flow of hypochlorite solution might be obtained. In this case a quart measure was used and ratios figured out in pints of hypochlorite per minute, For a permanent affair the tanks sho1uld be made of concrete or at least tled with cement, and adjustable means provided for drawing off the clear liquor from above as well as an outlet for removing the sludge at the bottom. It is recommended that the solution be allowed to settle for at least 8 hours and preferably over night. The standard stock solution thus prepared will contain available chlorine equal to -J lb. of chloride of lime per gallon, or about 2% available chlorine or 6% of chloride of lime by weight. </P> <P><PB REF="00000016.tif" SEQ="00000016" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000016"> </P> <P><PB REF="00000017.tif" SEQ="00000017" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="540" N="9"> Lbs. Chloride of lime o) C) c' -ru N) C C CO - ) > ) 1per 100,00000 gal.water ^ 0 2 0 0 0 r F H*..,, Parts Chloride of Lime i. 0. Parts Chlorine per H t O ~J O OO ~L^ eo ~ ~ 4s tl,, o o.coD o 0 o oH. o IU \ oN co 1,000,000, 00 parts wiater H ^..0.o0 0 0 Pr oe N H H- H H H H o o o Co H Grains Chloride of Lime d Ho0,O Co o \ c. o a p on 0 P per gallon of water O o *.. * Grains Available: H Co) 0 0 0 0 C) o Coo o 0 C 0 C) Chlorine per gallon of c <\ -. oj to PJ,., o, H' C Q) Jtf cHJ 0' H ^ 3 so W'-A w ater. P' 0 b tmi Drops Chloride of Lime t-.) U. )t to L 0 N) No N ~ H H H H. Sol. 2% Chlorine or H -- \Jr, NO O) _ vI O x N lb. Chloride of lime H ) \ o C) o \ o \n o \ o \u o Jni o \ o (per gal) used per gallon of water.. e3 </P> <P><PB REF="00000018.tif" SEQ="00000018" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000018"> </P> <P><PB REF="00000019.tif" SEQ="00000019" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="840" N="10"> LIQUID CILORINE:- Liquid chlorine is the trade name for liquefied chlorine gas. As stated befors the gas is generated by the electrolysis of brine. It is dried, compressed and cooled until it liquefies. In the coursd of this process the gas is relieved of all such impurities as water, carbon dioxide, oxygen, air, etc., so that the final product represents the elemenit chlorine in its most efficient form of about 99.5 to 99.9 per cent purity. Chlorine in this liquid state occupies only one four-hundredth ( 1/ 400 ) of the space of the gas under the same t emperature conditions anrd is placed in steel cylinders of about eighty lbs. weight having a capacity of 100 to 110 lbs. These units of about 180 lbs. gross xweight have been found to be the most convenient form for all practical purposes. The chlorine can be drawn off at will by opening the valve on the top of the cylinder. It does not matter how -amuch or how little is taken from the cylinder, liquid chlorine being the pure compressed gas, does not deteriorate or lose in efficiency by storing, as in the case with bleaching powder. The industry of chlorine liquefaction is of very recent date in this country, the first liquefying plant having been started only seven years ago. Since then the industry and the introduction of its product into new fields of application have grmaw very rapidly and it is now used extensively in textile mills, for general bleaching purposes and by the chemical manufact uring industries in various processes such as detinning, etc., after having shown </P> <P><PB REF="00000020.tif" SEQ="00000020" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000020"> </P> <P><PB REF="00000021.tif" SEQ="00000021" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="831" N="11"> considerable advantages as to high efficiency, easier handling and higher economy than other and older methods of application, Only after chlorine had thus been brought into a form whdch permitted convenient ha —ndling by the trade in general could it be considered feasible to conduct experiments with the idea of using its well known bactericidal properties for water sterilization by direct application. These experiments have been carried on by different scientists, the first to publish any results being Maj. C.R. Darnell, who in the fall of 1910 conducted laboratory tests with very good results basteriologically, but the method employed was not one of practical application for a large water -upply. Many experiments have been conducted since that time and many good results obtained. All of this experimental mrk demonstrated the advantageous features of the use of liquid chlorine and definitely determined its exceptional bactericidal properties, yet on the other hand -he drawbacks and inefficiencies of the various methods of applyi.ng the chemical were forcibly impressed upon the minds of those who attempted its control. The difficulty atrose in the develop:ment of a commercial and practical apparatus for efficiently regulating the rate of flow of the chlorine gas. Most of the failures on this score were due to the strong corrosive effects of chlorine on all kinds of metals, wood,:rubber, etc., Various types of controlling apparatus have been developed. They are knownm as either thie wet or dry f eed. In the dry feed the gas goes direct to the water supply, </P> <P><PB REF="00000022.tif" SEQ="00000022" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000022"> </P> <P><PB REF="00000023.tif" SEQ="00000023" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="841" N="12"> while in thewet feed the gas is first absorbed by a small quantity of water lwhich in turn is fed into the supply ~ The apparatus for the wet feed usually consists of a series of pipe coils for connecting the cylinders of gas to a manifold hpon which is placed a pressure gauge with a specially prepared diaphragm for determining the initial pressure and indicating when the cylinders are exhausted. Beyond this gauge two pressure regulating devices are installed, the first being used primarily for recucing the initial cylinder pressure and maintaining it at a predetermined mamimum, while the seoond is used for r-egulating this reduced pressure through a range sufficient to give the desired discharge of gas. To a branch outlet on the line between the last controlling valve and the discharge orifice there is attached a;low pressure chlorine gauge which is calibrateed empirically to indicate the rate of flow of g;as in pounds per hour. After passing the discharge outlet the gas is conducted by composition hardrubber tubing to an absorption tower designed to secure a thorough admixture of the chlorine in a minor quantity of water without the escape of any gas to the atmosphere~ This tower may be made. of stoneware, composition or any material which iill resist the chemical action of the gas during the absorption process. This tower is open to atmospheric pressure at the top and any failure bo secure an absolute absorption is indicated and known immediately by the presence of free chlorine in the atmosphere. The chlorinated water solution flows by gravity from the bottom of the tower to any desired point of application to the water supply'. It has been found that hard rubber composition makes a very good material for </P> <P><PB REF="00000024.tif" SEQ="00000024" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000024"> </P> <P><PB REF="00000025.tif" SEQ="00000025" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="122" N="13"> ?)/Pex OF CHLO~IlVE /CONTROL/ 1R4PPA/TU~..E..~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~...... I Model "D" glarer T y p e d pparatus 1 Wl11t~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~................S lS.!iiE tERaiSuEiii~:::EEEg:::E::::E:::EE~E:0::f::05Vi~ ES DnSigt::~a:::::::::::::!: -0-::::::S: Model "C" Metter ty~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~00S00000000000000e.00000000000000000I0000000000000000000para000000000:00000000000W0000000us00: ig 0000............ l~ ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~........I...... v S - -. W;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~......... </P> <P><PB REF="00000026.tif" SEQ="00000026" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000026"> </P> <P><PB REF="00000027.tif" SEQ="00000027" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="108" N="14"> ~ ~i~,~~~~~~~~~~~~~~~~~~~~~~~~~44,i,',44,1 >~~~~t ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~4..,~44.....>4, 6~~~~~~~~~4~ ~ ~ ~~~~~/ ~:::i ~l ~ LLI F ---------------- I:1; 4 4 4 ------- - -- - ------- MEc. CO3 SEEM44444 4,> 4 h~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >4>444>~. 4 Bgl~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~44 44 4444444r4 - a~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~4.44/4~It~B C~~~~~~~~~~~~~~~~~~~~~~~~~~~~t~~~~~~~.~.>'4.444 44>4 44~4. 444>4 < Wt2 W;"::: ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 44,. >4444444444,> > 4 ~ - 444 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~44 >4444 4b 4 >4.'r>a24 >~44. 44 >4<4 4444><4>4>4>4~4.'4~~~~~~~T~t 44 ><44444><4t>o ",44..4.,4.,.,,.~>4>44444444444444<~~>. 4 444444444/4 4>4>4>::::~ ~ ~ ~ ~ 4 4F; ~.444444+"'' 2 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~ ~~~~~~~~~~! ""\~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~4 4~~~~~~~~~~~~~~~~ 44~ 44 ~~~~~~p ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ r~~~~~~~4 Fi\~~~~~~~~~~'iD8~~~~~~~~~4i~~~~~i~~~~-~~~~~~~~~~~~;~~~~1. > >444. 4 i::~~:::: -::::::-:-::::::: s ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 4 </P> <P><PB REF="00000028.tif" SEQ="00000028" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000028"> </P> <P><PB REF="00000029.tif" SEQ="00000029" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="835" N="15"> the construction of these towers. They are filled with coke tomi give surface for the vwa.ter ihich trickles down from the top. CO0lMlPARISONS:- Mr..Frank D. West, chemist in charge of the Torresdale Laboratory, claims the following advantages of liquid chlorine over chloride of lime as used at the Torresdale filtration plant: 1. That liquid chlorine is an absolutely pure chemical concentrated in small cylindiers while chloride of lime is bulky, requiring large spaae for storing. 2. As to the saving in space required a one hund/,;ed pound cylinder occupies 64 sq. inches floor space. A stock'or fifty days at two hundred pounds per day would occupy a space of 45 ftuare feet five feet high. 20,000 lbs. of bleach, enoug for but seenteen days at twelve hundred pounds per day would occupy 160 sq. feet. Cn a basis of 6 to 1 about ten to eleven times -as much space is required for bleach as for liquid chlorine. 3. With efficient controlling devices liquid chlorine will eliminate the disagreeable odors and corrosive influences of chloride of lime; consequently the installation may be placed in position where the use of chloride of lime is impossible. 4. Liquid chlorine will retain its full efficiency over unlimited time whereas chloride of lime deteriorates rapidly. This is onie of the best arguments for liquid chlorine, especially for small installations. %. The floor space occupied by liquid chlorine plants is small, whereas chloride of lime installations require </P> <P><PB REF="00000030.tif" SEQ="00000030" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000030"> </P> <P><PB REF="00000031.tif" SEQ="00000031" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="776" N="16"> large mixing tanks, etc, The space occupied at Torresdale ior bleach treatment i:d ependent f the. spca for weiging was 22 by 16 feet; for tne liquid chlorine a-.pparatus; the cabinet is 2' by 4.4' and the space occupied by the twvers is 10' b:y about 2', 6. The reaction wirth liquid chlorine is simplified, while that vith c:loride bf lime is complex and less effective at low temperatures. The reactioYns for chloride of lime probably are C122 Ca2 CO H20 = Ca C03t 2 C10H t CaC12 a2O C1 2 J 2 C10H = 2 HC! ~ 0 2 HC1 + CaCO Ca C12 t H2 - C02 Jackson ( Sterilization of Cleveland Water Supply) gives the first part of the reactiin as CaC12 + H20 + C02 = CaC03+ HOC1 + HC1 For liquid chlorine Jackson gives C12 + H 0 - HOC1+ HC1 and HOC1 + HC1 = 2 IHC1 t- 0 It is a question if hypochlorous acid is formed and the author prefers the simple reaction of C1 2 H 0 2 HC1 + 2 2 This is a liberation of 23 - by weight of nascent oxygen and which together with'the powerful disinfecting action of the chlorine itself acting before it decomposes watAr gives the increased efficiency. 7., According to iMr. G, ID Jeckson (Proceedings American Waterworks As$$ociAtion, 1913) one pound liquid chlorine equals </P> <P><PB REF="00000032.tif" SEQ="00000032" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000032"> </P> <P><PB REF="00000033.tif" SEQ="00000033" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="810" N="17"> nine pounds chloride of lime; according to Mr. J. A. Kienle (Proceedings of American Waterworks Association, 1913) it equals eight. Theoretically it -;hould equal about three, but in practise considerable available chlorine is lost from the chloride of lime and the theoretical amount is nearer one to four. At Torresdale the rate is about one to six to one to seven. It is quite possible that *ith careless handling and storing of blleach at small plants the figure is nearzer one to eight than one to six. 8. No taste or odor appears in water treated with liquid chlorine. MIaj. Darnell stat.e that at least ttwo parts of lifquid chlorine, equivalent to sixteen pounds per million gallons inmust be used to give the slightest taste to Potomac river water. imr. Huy stated that wii7en using five pounds per million gallons a slight taste was noticed in the laboratories directly after dosing. On a test at t e Connecticut Hospital for the Insane, Middleto,'n, Corn, fourteen pounds per million gallons were used without its being noticed., It is quite possible that if th-e dosage is heavy enough the watter will rlave a taste o Firguring on a bais of six "to one, thirty pounds of chloride of lime would be needed to correspornd to 1Mr. Huy's five punnds; and eighty pounds to the amount mentioned by Mr. Darnell, From a close examuination of the literature on ehloride of lime the amount of chloride of lime tha.t wvill give a taste to. water:may be estimated at from seven to twenty pounds per million gallons of water, the average figure will be from ten to twelve. At the above rating this v:ouldi mean two,i pounds of liquid chlorine. A ileavy overdose can $e given without complaint, </P> <P><PB REF="00000034.tif" SEQ="00000034" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000034"> </P> <P><PB REF="00000035.tif" SEQ="00000035" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="828" N="18"> 9, Liquid chlorine does not change the character of the water by the introduction of lime salts. The lime salts will usually amount to not over one part per million. 10. Liquid chlorine necessitates no labor cost, while chloride of lime does. This is true, but a liquid chlorine apparatus requires skilled supervision to be operated properly and i not fool-proof. 11* Liquid -hlorine leaves no sludge, 12* Liquid chlorine will reduce the amount df alum needed for bacterial removal. There can be no question but that, in cases Where the water is comparatively clear and where alwn is used chiefly for bacterial removal, if liquid chlorine is used before filtration it vwill make a marked saving in the cost of alum and in many cases will not only' pay for itself but will decrease th.e general cost of the plant. A saving of one half grain per gallon or alum at one cent per pound by the u e of one pound iiquid chlorine pel million gallons at ten cents means a saving of 61 cents per million gallons. 13* The feed of liquid chlorine is regular from hour to hour and the feed of chloride of lime varies constantly Objections to JUse of Liquid Chlorine:- The chief objecti:n to the use of liquid chlorine lies in the concentrated energy of the material itself. If liquid chlorine is set free in small enclosures it will cause nausea. With ordinary co-mnon sense and judgment on the part of the &perator this is not likely to happen.'[he greatest danger lies in faulty cylinders arid faulty valves, If the cylinder valve were not turned off or if the cylinder leaks, it msut </P> <P><PB REF="00000036.tif" SEQ="00000036" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000036"> </P> <P><PB REF="00000037.tif" SEQ="00000037" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="798" N="19"> ce got out into the open air and the chlorine allowed to escape. Careful inspection of cylinders and va:lves must be made. Liquid chlorine, whi.e.- it comes in contact with moisture has a very corrosive action, but this has been overcome by the use of hard rubber pipes and towers. COSTS:- A- true comparison of costs carinnot be made on present prices, as the European War has caused a tremiendous inorea se in the cost of uthese ch emicals. Probably one of' the'est compari sons un-rder normal conditions is that furnished bMy Mr. West at t.e Torresdale plant, tihich is as follows: Chloride of lime costs us from $1.22 to "1o70 per hundred pounds, the usual quotation was $1.34 and the average figure $1. 40 Taking $1,40 as a basis; we used during 1913 an average of a little over twelve hundred pounds a day or $16o.80 a day for powder. Two laborers at 250 per hour were employed for eight hours or $ 4.00. per day, making a total cost of $20.80 per day exclusive of repairs, sample collecting or laboratory analysis. One hundred a.d eighty pounds of liquid chlorine (the amount used April 10) would coqt at ten cents per pound $18.00 per day. We have nowv passed the:r.or't conditions of the year, February and MTJ"rch, w-henr we used 234 pounds a cay or 4|23.40 cost. It is expected that we will be able to reduce the amount of liquid chlorine to at least lb. per million or 120 lbs. a day. We reached this Anril 22. </P> <P><PB REF="00000038.tif" SEQ="00000038" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000038"> </P> <P><PB REF="00000039.tif" SEQ="00000039" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="818" N="20"> Some supervision and handling of cylinders is required. At present the wrork is done by a $3.00 a day mechanic who also keeps the pre-filters in repair. His wages are charged against the pre-filter. A charge of $1,00 a day 7woulld be fair for this service. This is partly balanced'by the discontinuance of laborator'y analyses. The labor cost during 1913 of $4,00 per day with its output of 180,000,000 gallons amounted to but 2.2/ per million gallons. At Belmont and at Queen Lane the labor cost of about $1.50 per day amounted to 3.8%f and 3/ respectively. A-t the Roxboro plant the labor cost averaged over $1.00 per day mixing; this at Lower Roxboro cost 10 per million and at Upper Roxboro 6.7% per million. The cost per million gallons at these plants during 1913 amounted to 16% to 18/, At one pound per million gallons for liquid chlorine the cost would be 10%, or a saving of 6f to 8%f per million gallons. On April 14 the quantity used was reduced to j lb. per million or a cost of 5%, a saving of 1 to 13% per million. Belmont and Queen Lane are saving a labor cost of 3.8g and 3% per million gallons, Belmont is operating at a rate of -i lb. and Queen Lane at j lb., or about 5% each. On April 21 the amount used at Torresdale was reduced to 4 lb. or a cost of $13.5~0 per day, exclusive of a possible charge of $1.00 for labor* In general the cost of the two processes should be about equkl; if anything, liquid chlorine should prove the ch eap erz In an article enmitled "The Cost of Water Purification </P> <P><PB REF="00000040.tif" SEQ="00000040" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000040"> </P> <P><PB REF="00000041.tif" SEQ="00000041" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="821" N="21"> as affected by the War" publi.hed in the last numfber of the Journal of the American Medical Association the following i s given: The prices of certain chemicals used in water purification have risen greatly on account of the w.ar.The actual amount of chemicals used in water purification plants is insignificant from the standpoint of total consumption, and at present the difficulty of the situation consists in the fact tht the waterworks officials are at the mercy of thxe prices set by the needs of the manufacturers of explosives, and of many industrial processes.'The normal price of bleaching pqwder, for example, on the New York Market, is about $1.25 to 41.35 per cwt., wihile the New York wholesale quotation, Mar.4%, 1916, were from $10.50 toA$2.50 per cwt, Fortunately the advance in cost of liquid chlorine has been much less(about double the normal rate), so that chlorine disinfection may still be inexpensively carried out. It is to be hoped that waterworks officials will be on their guard against any tendency towards a lowering of the efficiency of purification because of the rise in operating expense. Here if anywhere, the motto "Safety First" has its place. Any saving effected in the quantity of chlorine or other chemicals used is trivial compared with the pos.;ible dangers of infection. The present chemical situation suggests at most the substitution of liquid chlorine for calcium hypochlorite, and where prattical, of lime or iron sulphate for aluminum sulphate. Wallace and Tiernan Co. Inc., of New York, give the following comparisons as to cost of apparatus: The average c:ost of a hypochlorite dosing device is </P> <P><PB REF="00000042.tif" SEQ="00000042" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000042"> </P> <P><PB REF="00000043.tif" SEQ="00000043" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="825" N="22"> $3000O0, including mixing tank and machinery, constant level boxes, orifices, etc,. Thi snwould be typical of the cost for a small plant, with that for larger plants, higher in proportion. The price of chlorine control apparatus (based on twelve types manufactured by this company), will run from $350o00 to $1200.00 depending upon the "type and capacityof the apparatus, and the conditions under w^hich it is to be installed. A fair average figure for the cost of a chlorinator would be $525.00. On this basis the average chlorinator costs $225,00 more than the average hypochlorite dosing device. CONCLUSIONS:- From the previous c.mparisons of efficiency, ease of application and costs it is evident that liquid chlorine has many advanttages over chloride of lime as a disinfectant in water purification. Nevertheless chloride o:E' lime still holds a valuable positio4 in this field and cannot be cast asid e at this time. In discussing the subject ME. C. A. Jennings wrote the following: The automobile has replaced the h;orse for many purposes but has not elimina'dd the horse. The writer feels that liquid chlorine will supplant hypo in many plants now using hypo, and that it w-ill be installed in a large number of cities,, not now using any disinfectant, in preference to hypo. However, he does not believe that hypo will be eliminated. It will probably be used for smaller installations, because of the smaller installation cost for the small and medium sized plant, and will be used to quite an extent f'r sewage, where'the odor from the drum and the turbid solution </P> <P><PB REF="00000044.tif" SEQ="00000044" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000044"> </P> <P><PB REF="00000045.tif" SEQ="00000045" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="814" N="23"> will not be objectionable. He does not believe thatt all the drawbacks laid to hypo are correctly placed. Many of the troubles laid to the use of hypo are really due to lack of attention; faulty design of treatment plant; incomplete mixing of the solution; expecting from the use of hypo a greater removal of bac teria than i s aeally practicable or necessary, and the adjustmernt of the lose. to obtain this;maxin mum r emo val Mr. Geo, C. Whipple expressed himself a.s follows: It seems evident that both calciLu hypochlorite and liquid chlorine may be relied upon to disinfect water supply and that Lhe two processes are about on a par as to the efficiency and freedom from taste and odor,, provided that both chemicals areadded to the water in proper amounts and with prope;r regularity. The advantages of liquid chlorine over calcium hypochlorite appear to lie in the field of ecomoxiy and convenience, It is not clear that in all cases liquid chlorine is cheaper; Both chemicals probably have their special adaptations and with time these will become defined.. From a comparison of a large amount of. data, one is greatly impressed by the very varied conditions under which these chemicals are used. Some waters being turbid and high, in organic matter while others are either filtered supplies or relatively clear waters, Therefore an estimate of tlhe amlounts necessary for any particular supply, by corparision li th, ther suppliess i impossible. The condition of the tater changes from day to day not only in temperature and ttirbidity but in dissolved organic matter which claims first use of the nascent oxygen giv-n off so that no d~finite dose can be s.sld to be correct for all times. Any </P> <P><PB REF="00000046.tif" SEQ="00000046" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000046"> </P> <P><PB REF="00000047.tif" SEQ="00000047" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="571" N="24"> di sinrlfec tion process, snoiWAl oe uc(comipani ea mu/ iao oraC r ry control. In lth.i way.; ani econoimical and reliable dose m; ay be applied according to tie condition ofi the water. i th tne remnarkablae ad vancereentiute xi~dth tfhele dis infecting; a..Fjenrcien int t''e past f~, years and th r;elative eat e arid co t Qf appli;ction to'watei slapplie amnd sewaige afilu eocic@ tere' is lo xose for t yphoid oo'r O l ~hr. iater- orne di,seas"e,. </P> <P><PB REF="00000048.tif" SEQ="00000048" RES="600dpi" FMT="TIFF6.0" FTR="UNSPEC" CNF="100" N="00000048"> </P> </DIV1> </BODY> </TEXT>