title: Effects of an electric field and zero valent iron on anaerobic treatment of azo dye wastewater and microbial community structures.
abstract: A zero valent iron (ZVI) bed with a pair of electrodes was packed in an anaerobic reactor aiming at enhancing treatment of azo dye wastewater. The experiments were carried out in three reactors operated in parallel: an electric field enhanced ZVI-anaerobic reactor (R1), a ZVI-anaerobic reactor (R2) and a common anaerobic reactor (R3). R1 presented the highest performance in removal of COD and color. Raising voltage in R1 further improved its performance. Scanning electron microscopy images displayed that the structure of granular sludge from R1 was intact after being fed with the high dye concentration, while that of R3 was broken. Fluorescence in situ hybridization analysis indicated that the abundance of methanogens in R1 was significantly greater than that in the other two reactors. Denaturing gradient gel electrophoresis showed that the coupling of electric field and ZVI increased the diversity of microbial community and especially enhanced bacterial strains responsible for decolorization.
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian, China.
authors.forename: Yiwen
authors.initials: Y
authors.lastname: Liu
authors.forename: Yaobin
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xie
authors.initials: X
authors.lastname: Quan
authors.forename: Jingxin
authors.initials: J
authors.lastname: Zhang
authors.forename: Huimin
authors.initials: H
authors.lastname: Zhao
authors.forename: Shuo
authors.initials: S
authors.lastname: Chen
mesh_terms: D001391:Azo Compounds / Q000378:metabolism*; D001421:Bacteria, Anaerobic / Q000302:isolation & purification* / Q000502:physiology* / Q000528:radiation effects; D004396:Coloring Agents / Q000378:metabolism* / Q000528:radiation effects; D004574:Electromagnetic Fields; D007220:Industrial Waste / Q000517:prevention & control*; D007501:Iron / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification / Q000379:methods*
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D007220:Industrial Waste; D014874:Water Pollutants, Chemical; D007501:Iron