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 condition to assess the concentration effects of the substrate and microorganisms on the in-situ bioremediation of 1,1,1-trichloroethane (TCA). Experimental results demonstrated that the addition of higher concentrations of the substrate and microorganisms would enhance the biotransformation of TCA The biotransformation rate of TCA increased progressively with the increase of the concentrations of the substrate and microorganisms. 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 biomass-amended system when the supplemental substrates were acetate and glucose, respectively, with the concentration ranging from 10 to 100 mg/L. Whereas great than 99 % and 52% to 62% of TCA removals were observed in the heavily inoculated system with the amendment of glucose and acetate, respectively. The degradation second order rate constants of TCA, k2, ranging from l.67 x 10−4 L/mg/day to 4.49 x 10−4 L/mg/day and from 0.64 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 bioremediation of groundwater contaminated with heavily chlorinated hydrocarbons is feasible in aquifer systems with appropriate concentrations of substrate and microorganisms.