An industrial client required a wastewater treatment process to treat a variety of wastewaters including oily bilge water, airport deicing glycol wastewater, and landfill leachates. Glycol wastewater resulting from aircraft deicing is very high in COD and often arrives at the plant in concentrations as high as 4%, in quantities which depend on the weather conditions.

ABL conducted treatability studies on the glycol wastewater and developed design criteria for the treatment system. The system was designed for a COD load of 1,100 kg/d. The system consists of flow equalizing tankage, dissolved air flotation (DAF) for pretreatment to remove oils, an 8,750 cubic meters extended aeration activated sludge system complete with clarifier, and an effluent equalization pond. Aeration is by subsurface fine bubble aerators and mechanical surface aerators.