Azo dye decolorization in an up-flow bioelectrochemical reactor with domestic wastewater as a cost-effective yet highly efficient electron donor source.
A major challenge of employing bioelectrochemical system (BES) for reductively degrading recalcitrant contaminants in industrial wastewater is lacking sufficient electron donors. In this work, domestic wastewater (DW) was demonstrated to efficiently drive BES for implementing the decolorization of azo dye, acid orange 7 (AO7). Side benefit was the simultaneous treatment of DW. Decolorization efficiency in BES fed with DW (RDW) was found to be comparable with that either fed with glucose (RGlu) or acetate (RAc). Much lower reductant usage ratio was observed in RDW. As a result, when the ratio of electron donors to azo dye decreased to 4.4 mol COD mol-1AO7, DE of RDWkept over 90% while DEs of RAcand RGluwere significantly dropped due to the insufficient electrons donation. Besides serving as electron donor, DW was proved to also provide some conductivity and buffer capacity. Accordingly, DE of RDWwas less deteriorated when fully removing the external buffer slats. This study comprehensively revealed the feasibility and superiority of DW as a cost-effective electron donor source in BES and brings this technology closer to the practice.
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
Min-Hua
MH
Cui
Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China.
Dan
D
Cui
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
Lei
L
Gao
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China; Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China. Electronic address: waj0578@hit.edu.cn.
Ai-Jie
AJ
Wang
Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China. Electronic address: hycheng@rcees.ac.cn.
Hao-Yi
HY
Cheng
D001391:Azo Compounds; D019149:Bioreactors; D004396:Coloring Agents; D004583:Electrons; D062065:Wastewater
D001391:Azo Compounds; D004396:Coloring Agents; D062065:Wastewater
Azo dye; Bioelectrochemical system; Cost-effective; Domestic wastewater; Electron donor source