ANAEROBIC DEGRADATION OF 1,1,1-TRICHLOROETHANE WITH THE AMENDMENT OF DIFFERENT SUBSTRATE AND MICROBIAL CONCENTRATIONS

An investigation involving the supplement of different concentrations of a substrate and microorganisms was carried on under anaerobic condi tion to assess the concentration effects of the substrate and microorg anisms on the in-situ bioremediation of 1,1,1-trichloroethane (TCA). E xperimental results demonstrated that the addition of higher concentra tions of the substrate and microorganisms would;enhance the biotransfo rmation of TCA. The biotransformation rate of TCA increased progressiv ely with the increase of the concentrations of the substrate and micro organisms. Whereas the acclimation had an opposite effect. 17 % to 57 % and 26 % to 41 % of TCA removals was exhibited in 0.56 mg-VSS/L biom ass-amended system when the supplemental substrates were acetate and g lucose, respectively, with the concentration ranging from 10 to 100 mg /L. Whereas great than 99 % and 52 % to 62 % of TCA removals were obse rved in the heavily inoculated system with the amendment of glucose an d acetate, respectively. The degradation second order rate constants o f TCA, k(2), ranging from 1.67 x 10(-4) L/mg/day and from 0.64 x 10(-4 ) to 16.9 x 10(-4) L/mg/day to 4.49 x 10(-4) L/mg/day to 16.9 x 10(4) L/mg/day for glucose- and acetate-amended batches, respectively, were also demonstrated for a wide range of experimental settings. Based on results in this study, we can conclude that the biormediation of groun dwater contaminated with heavily chlorinated hydrocarbons in feasible in aquifer systems with appropriate concentrations of substrate and mi croorganisms. Copyright (C) 1996 Elsevier Science Ltd