title: Simultaneous sulfate and zinc removal from acid wastewater using an acidophilic and autotrophic biocathode.
abstract: The aim of this study was to develop microbial electrolysis cell (MEC) with a novel acidophilic and autotrophic biocathode for treatment of acid wastewater. A biocathode was developed using acidophilic sulfate-reducing bacteria as the catalyst. Artificial wastewater with 200mgL(-1) sulfate and different Zn concentrations (0, 15, 25, and 40 mg L(-1)) was used as the MEC catholyte. The acidophilic biocathode dominated by Desulfovibrio sp. with an abundance of 66% (with 82% of Desulfovibrio sequences similar to Desulfovibrio simplex) and achieved a considerable sulfate reductive rate of 32 gm(-3)d(-1). With 15 mg L(-1) Zn added, the sulfate reductive rate of MEC improved by 16%. The formation of ZnS alleviated the inhibition from sulfide and sped the sulfate reduction. With 15 and 25 mgL(-1) Zn added, more than 99% of Zn was removed from the wastewater. Dissolved Zn ions in the catholyte were converted into insoluble Zn compounds, such as zinc sulfide and zinc hydroxide, due to the sulfide and elevated pH produced by sulfate reduction. The MEC with acidophilic and autotrophic biocathode can be used as an alternative to simultaneously remove sulfate and metals from acid wastewaters, such as acid mine drainage.
authors.affiliation: School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, Guangdong, China.
authors.forename: Wenkai
authors.initials: W
authors.lastname: Teng
authors.affiliation: School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, Guangdong, China.
authors.forename: Guangli
authors.initials: G
authors.lastname: Liu
authors.affiliation: School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, Guangdong, China. Electronic address: luohp5@mail.sysu.edu.cn.
authors.forename: Haiping
authors.initials: H
authors.lastname: Luo
authors.affiliation: School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, Guangdong, China.
authors.forename: Renduo
authors.initials: R
authors.lastname: Zhang
authors.affiliation: School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, Guangdong, China.
authors.forename: Yinbo
authors.initials: Y
authors.lastname: Xiang
mesh_terms: D001419:Bacteria / Q000378:metabolism; D019149:Bioreactors; D002384:Catalysis; D004566:Electrodes; D004572:Electrolysis; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D013431:Sulfates / Q000378:metabolism*; D014865:Waste Disposal, Fluid; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
chemical_list: D013431:Sulfates; D062065:Wastewater; D014874:Water Pollutants, Chemical; D015032:Zinc
keywords: Acidophilic biocathode; Bacterial community; Desulfovibrio simplex; Sulfate removal; Zinc removal