ANAEROBIC FLUIDIZED-BED TREATMENT OF PROPELLANT WASTE-WATER

Treatment of propellant wastewater by anaerobic fluidized-bed bioreact ors (FBRs) containing granular activated carbon has been shown to be e ffective in laboratory and field feasibility studies. These studies we re conducted in 100 mm (4 in.) diameter columns (8 L volume) treating low volumes of water taken directly from a propellant-production opera tion. The contaminant of interest, dinitrotoluene, was converted anaer obically to diaminotoluene (DAT), with subsequent aerobic mineralizati on of the DAT in an activated-sludge process. A demonstration of this technology has been conducted at Radford, Virginia, Army Ammunition Pl ant, using a commercially available 500 mm (2O in.) diameter column (7 10 L volume) FBR modified for anaerobic operation. The FBR was followe d in series by a rotating biological contactor to simulate anaerobic p retreatment at a point source, followed by aerobic treatment at the ex isting facilities. Significant differences in the composition of the w astewater stream were encountered between the feasibility study and de monstration. The concentrations of easily degraded solvents (ethanol a nd ether) were much lower during the demonstration than during the fea sibility studies, The events encountered in scaling up the process fro m the laboratory to pilot scale are reported, and the results of the p ilot-scale demonstration are compared with the laboratory-scale data.