Application of sieve-tray air strippers to the treatment of surfactant-containing wastewaters

Abstract

Using sieve-tray air stripping as a means of removing contaminants from surfactant solutions was studied to determine if tray air stripping can be applied successfully to treating surfactant-containing wastewaters and, if so, to develop a quantitative approach for designing tray air-stripping systems for treating surfactant-containing wastewaters. High-concentration surfactant solutions were prepared and contaminated with five different volatile organic compounds. Removal of the organic compounds was evaluated using a commercial sieve-tray air stripper. Overall, the air stripper was able to efficiently remove the contaminants from solution, and correction of Henry's Law constants for micellar solubilization-induced volatility reduction allowed tray air-stripper design equations to quantitatively predict air-stripper removal for all contaminants. Foaming within the air stripper could be controlled with low concentrations of a silicone-polymer antifoaming agent. Although adding antifoaming agents may be undesirable for some applications, other applications can benefit from the operational and performance advantages of sieve-tray air strippers. Issues related to air-stripper design for low-volatility compounds are also discussed.