MODELING OF THE FATE AND EFFECT OF CHLORINATED PHENOLS IN ANAEROBIC TREATMENT PROCESSES

Studies were conducted to assess the biotransformation kinetics and in hibitory effects of mono-, di-, and trichlorophenol on acetogenic and methanogenic reactions using a standardized anaerobic protocol (Young and Tabak, 1993). Intrinsic kinetic parameters were estimated for each reaction using the Monod model. Reductive dechlorination of the toxic ants was investigated using acclimated mixed cultures under methanogen ic conditions. The studies indicated that inhibition of acetogenesis a nd methanogenesis was best described using exponential rather than lin ear inhibition terms. A second significant observation was that acclim ated test cultures had a finite biodegradation capacity for each chemi cal that was related to the mass of microorganism present. A unique fe ature of the test program was that inhibition and biodegradation were modeled using the specific biomass responsible for acetogenesis and me thanogenesis rather than the total anaerobic biomass. (C) 1997 IAWQ. P ublished by Elsevier Science Ltd.