Groundwater cleanup by in-situ sparging .12. An improved aeration curtain design

The performances of three designs of aeration curtains are modeled mathematically, and the results of model computations are used to compare the efficiencies of the designs. The efficiency of the standard crosscurrent design for trichloroethylene (TCE) removal is found to be substantially less than that of a crosscurrent/countercurrent design in which a vertical barrier in the curtain causes flow of the water countercurrent to that of the air. This design, in turn, is less efficient than a design in which the bottom section of the curtain is operated in a purely countercurrent mode. Model calculations indicate that this last design is readily able to achieve removals of volatile organic compounds such as TCE of better than 99%. The implications of the three designs for bioremediation are explored; all provide satisfactory oxygen transfer. Aspects of construction and implementation are discussed.