Natural attenuation model and biodegradation for 1,1,1-trichloroethane contaminant in shallow groundwater
نویسندگان
چکیده
Natural attenuation is an effective and feasible technology for controlling groundwater contamination. This study investigated the potential effectiveness and mechanisms of natural attenuation of 1,1,1-trichloroethane (TCA) contaminants in shallow groundwater in Shanghai by using a column simulation experiment, reactive transport model, and 16S rRNA gene clone library. The results indicated that the majority of the contaminant mass was present at 2-6 m in depth, the contaminated area was approximately 1000 m × 1000 m, and natural attenuation processes were occurring at the site. The effluent breakthrough curves from the column experiments demonstrated that the effectiveness of TCA natural attenuation in the groundwater accorded with the advection-dispersion-reaction equation. The kinetic parameter of adsorption and biotic dehydrochlorination of TCA was 0.068 m(3)/kg and 0.0045 d(-1). The contamination plume was predicted to diminish and the maximum concentration of TCA decreased to 280 μg/L. The bacterial community during TCA degradation in groundwater belonged to Trichococcus, Geobacteraceae, Geobacter, Mucilaginibacter, and Arthrobacter.
منابع مشابه
Substrate interactions during aerobic biodegradation of methane, ethene, vinyl chloride and 1,2-dichloroethenes.
Intrinsic biodegradation of trichloroethene and 1,1,1-trichloroethane in groundwater at a Superfund site in California has been observed. An anaerobic zone exists in the area closest to the source location, yielding the expected complement of reductive dechlorination daughter products, including cis-1,2-dichloroethene (cis-DCE) and vinyl chloride (VC). Significant levels of methane and ethene w...
متن کاملLarge Carbon Isotope Fractionation during Biodegradation of Chloroform by <italic>Dehalobacter</italic> Cultures
Compound specific isotope analysis (CSIA) has been applied to monitor bioremediation of groundwater contaminants and provide insight into mechanisms of transformation of chlorinated ethanes. To date there is little information on its applicability for chlorinated methanes. Moreover, published enrichment factors (ε) observed during the biotic and abiotic degradation of chlorinated alkanes, such ...
متن کاملModelling the Fate of Petroleum Hydrocarbons in Groundwater
Models can be powerful tools to aid interpretation of data and for prediction of the fate of contaminants, as in the case of petroleum hydrocarbons in groundwater environments. Here we describe the transport processes that can be more or less dominant at different stages in the ‘life’ of a petroleum contaminant spill in groundwater, such as advection, dispersion, dissolution from free-phase non...
متن کاملThe effect of silica on the degradation of organohalides in granular iron columns.
Dissolved silica species are naturally occurring, ubiquitous groundwater constituents with corrosion-inhibiting properties. Their influence on the performance and longevity of iron-based permeable reactive barriers for treatment of organohalides was investigated through long-term column studies using Connelly iron as the reactive medium. Addition of dissolved silica (0.5 mM) to the column feed ...
متن کاملChlorinated solvents in groundwater of the United States.
Four chlorinated solvents-methylene chloride, perchloroethene (PCE), 1,1,1-trichloroethane, and trichloroethene (TCE)-were analyzed in samples of groundwater taken throughout the conterminous United States by the U.S. Geological Survey. The samples were collected between 1985 and 2002 from more than 5,000 wells. Of 55 volatile organic compounds (VOCs) analyzed in groundwater samples, solvents w...
متن کامل