Degradation Mechanism of Trichloroethane and Dioxane Co-Contamination Via a Zvi-Anaerobic Microbe Combined System

Degradation mechanism of trichloroethane and dioxane co-contamination via a ZVI-anaerobic microbe combined system

Li-hua Fana, Hui Lia(, Ji-dong Guc, Jie Yangd, Qiang Lua, Zhi-yuan Suna, Qiu-yue Fenga, Ya-qing Chena, Kuang-fei Lina, Yong-di Liu a(


a State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, P.R. China;
b School of Biological Engineering, East China University of Science and Technology, Shanghai 200237, P.R. China;
c School of Biological Sciences, Swire Institute of Marine Science, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, P.R. China
d Research Institute of Wastes and Soil Remediation, Shanghai Academy of Environmental Sciences, Shanghai 200233, PR China

(Corresponding author:
Hui Li
Email: huili@ecust.edu.cn
Yong-di Liu
Email: ydliu@ecust.edu.cn
Tel.: +86 21 64251758; fax: +86 21 64253188
Abstract: Trichloroethane (TCA) and dioxane often occur in soil and groundwater in the form of complex contaminants. In this study, a zero-valent iron (ZVI)-anaerobic sludge combined system obtained over 300 d of acclimation in an upflow anaerobic sludge blanket (UASB) reactor was developed to treat a TCA and dioxane-complex pollutant (both at 70 mg/L), and it presented removal percentages of 97.5% and 92.0%, respectively. TCA generated chloroethane (CA) through reductive dechlorination of ZVI, and the CA concentration in the effluent was 21.8 mg/L, whereas the Fe2+ and Fe3+ concentrations were 144.2 mg/L and 20.34 mg/L, respectively. An analysis of 16S rRNA gene libraries showed that the anaerobic sludge contained six bacteria species, including Clostridia, Betaproteobacteria, Deltaproteobacteria, Gammaproteobacteria, Alphaproteobacteria and Bacilli, of which Ferribacterium limneticum cda-1 and bacterium UWNR3 were Fe...