SELECTING AMONG PHYSICAL/CHEMICAL PROCESSES FOR REMOVING SYNTHETIC ORGANICS FROM WATER

A rational framework for selecting the least-cost treatment technology for aqueous organic wastes was developed by using performance and cost models. The following three treatment options were evaluated for 15 different chemicals in this research: packed tower air stripping, packed tower air stripping followed by gas-phase adsorption (granular activated carbon) of off-gases, and liquid-phase adsorption (granular activated carbon). The least-cost air stripping tower design was found to change when off-gas treatment was added. Air stripping without off-gas treatment was determined to be less expensive than liquid-phase adsorption in nearly every case. A methodology was created for comparing the relative costs of liquid-phase adsorption and air stripping with gas-phase adsorption. The comparison methodology is based upon physical parameters of the target chemical: Henry's constant and the solute distribution parameter. The result is a diagram for rapid identification of cases for which one treatment option is significantly less expensive than the other.