Biological treatability of U.S. Navy aircraft paint stripping wastewater using activated sludge and rotating biological contactor processes

The U.S. Navy operates 41 shore aircraft paint stripping facilities that generate over 300 million gallons per year of highly contaminated wastewater which can include one to several of the following: phenols, methylene chloride, trichloroethylene, ortho dichlorobenzene, cresols, chromates, potassium hydroxide, ammonia, and sodium hydroxide. The six Naval Air Rework Facilities (NARFs) are the major generators, accounting for more than 95 percent of the total volume of the wastewater.;The current treatment practice at the NARFs includes joint treatment to remove heavy metals and cyanide. The lack of effective treatment options for removing toxic organics in the paint stripping wastewater, coupled with the introduction of stringent pretreatment Federal Metal Finishing Regulations and National Pollutant Discharge Elimination System (NPDES) standards with respect to toxic organics, dictates the need for additional treatment for removing these constituents.;This study was aimed at the determination of the biological treatability of U.S. Navy aircraft paint stripping wastewater using aerobic processes, namely, the aerobic suspended growth process (ASGP), i.e., activated sludge, and the aerobic attached growth process (AAGP), i.e., Rotating Biological Contactor (RBC). Both synthetic and actual wastewaters were used in the study.;The activated sludge process study was divided in two parts, namely ASGP I and ASGP II, and conducted in the batch mode. The ASGP I study was aimed at establishing the biological treatability of aircraft paint stripping wastewater. Parallel experiments were conducted to determine the extent of removal of pollutants by air stripping. The ASGP II study focused on three acclimation procedures (acclimation in the presence of glucose and nutrients, sewage and nutrients, and nutrients) and batch kinetics.;The RBC study involved both batch and continuous flow modes of operation. Batch RBC experiments involved two distinct methods of acclimation/treatment in the presence of glucose and nutrients and sewage and nutrients, and batch kinetics. The continuous flow RBC experiments were aimed at studying the treatability of both synthetic and actual U.S. Navy aircraft paint stripping wastewater in the presence of sewage and nutrients in varying proportions. The biological kinetic coefficients P and K...