Fate of selected RCRA compounds in a pilot-scale activated sludge system

This research determined the removal and fate of 11 selected RCRA compounds in a pilot-scale activated sludge system with a 4-day SRT and 7.5-hour HRT. Screened and degritted raw wastewater from a Cincinnati, OH, wastewater treatment plant was used for this study at the U.S. EPA's Test and Evaluation (T&E) Facility. A continuous feed of spike toxic cocktail of 0.25 mg/L each of acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, carbon tetrachloride, 1,1,1-trichloroethane, 1,1,2-trichloroethane, trichloroethylene, tetrachloroethylene, chlorobenzene, and ethylbenzene was used to produce an acclimated biomass. The test was run for 7 weeks. Volatilization losses in primary sedimentation exceeded 10% for carbon tetrachloride, 1,1,1-trichloroethane, 1,1,2-trichloroethane, and tetrachloroethylene. Sorption of the 11 compounds to primary and secondary sludge ranged from 0.6 to 5.1%. Nine of the 11 test compounds were removed > 94% with estimated biodegradation ranging from 0 to 93.4%.