COMETABOLIC DEGRADATION OF 1,1-DCE WITH BENZENE AS THE PRIMARY SUBSTRATE BY AEROBIC SLUDGE

摘要

Laboratory batch experiments have been performed with aerobic sludge obtained from a sewage treatment plant in Beijing to investigate the cometabolic degradation of 1,1-dichlorethlyene (DCE) with benzene as the primary substrate. The model incorporated competitive inhibition, the stimulating effect of growth substrate and the distribution of DCE and benzene in the liquid and gas phase was proposed to describe the degradation kinetics of 1,1-DCE. The experiments revealed that the optimum benzene concentration for 1,1-DCE degradation varied with the initial concentration of 1,1-DCE. Benzene needed to be below l0mg/L prior the onset of biodegradation of DCE. The maximum specific degradation rates (k_c) for 1,1-DCE and benzene (ks) were 0.105±0.002 (u.g DCE/ (mg.VSS.hr)) and 0.0155+0.001 (mg benzene/(mg. VSS.hr)), respectively. The half-saturation constant of 1,1-DCE and benzene were 137.1±4.2 (μg/L) and 27.6±0.07 (mg/L), respectively. In addition, the model predictions conformed well to the observed data for 1,1-DCE and benzene with all the correlation coefficients greater than 0.99.