TREATMENT OF SEMIVOLATILE COMPOUNDS IN HIGH-STRENGTH WASTES USING AN ANAEROBIC EXPANDED-BED GAC REACTOR

The potential of the anaerobic, expanded-bed granular activated carbon (GAC) reactor in treating a high strength waste containing RCRA semivolatile organic compounds (VOCs) was studied. Six semivolatiles, orthochlorophenol, nitrobenzene, naphthalene, para-nitrophenol, lindane, and dibutyl phthalate, were fed to the reactor in a high strength matrix of background solvents consisting of acetate, acetone and methanol. Performance was evaluated over a period of days. The reactor was found to effect complete removal of all the semivolatile compounds with the exception of orthochlorophenol. Removal of orthochlorophenol ranged from 77 to 99%. Removal of all the semivolatiles was elucidated relative to adsorption and biodegradation. With the exception of naphthalene, which was found to be completely removed by adsorption, all the other semivolatiles were removed primarily by biodegradation. COD removals in excess of 90% were also observed throughout the study.