Enhanced performance and microbial community analysis of bioelectrochemical system integrated with bio-contact oxidation reactor for treatment of wastewater containing azo dye

• Published in: The Science of the total environment 2018-09, Vol.634, p.616-627
• Main Authors: Wang, Youzhao, Pan, Yuan, Zhu, Tong, Wang, Aijie, Lu, Yalun, Lv, Liting, Zhang, Kuo, Li, Zijun
• Format: Article
• Language: English
• Subjects: Azo dye removal; Bio-contact oxidation; Bioelectrochemical systems; Microbial community structure; Response surface methodology
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2018.03.346

Feasibility and superiority of the bioelectrochemical system integrated with biocontact oxidation (BES-BCO) for degradation and/or mineralization of azo dyes have been confirmed. In this study, the effects of hydraulic retention time (HRT), applied voltage, and dissolved oxygen (DO) concentration at the bioanode on the performance of BES-BCO and traditional BES were investigated. Using the response surface methodology, the optimum values of HRT, applied voltage, and DO concentration at the bioanode of BES-BCO were investigated to obtain the maximum decolouration and COD removal efficiency and minimum specific energy consumption (SEC). The microbial community structure in BES-BCO was studied for analyzing the change following the introduction of oxygen. The optimised solution was an applied voltage of 0.59V, HRT of 12h, and DO concentration of 0.96mg/L at the bioanode. Under such conditions, the DE, COD removal efficiency, and SEC values were 94.62±0.63%, 89.12±0. 32%, and 687.57±3.86J/g, respectively. In addition, after changing from BES to BES-BCO, the bacterial community structure of the bioanode underwent significant changes. Several aerobic aniline-degrading bacteria and anode-respiration bacteria (ARB) were found to dominate the community of the anode biofilm. The results showed that the removal of azo dye degradation by-products was closely correlated with the o-bioanode and the BCO bacterial community structure. [Display omitted] •The effects of HRT, applied voltage and DO on the performance of BES-BCO without and with BCO were investigated.•The optimised condition was an applied voltage of 0.59 V, HRT of 12 h, and DO concentration of 0.96 mg/L at the bioanode.•Under the optimization conditions, the DE, COD removal efficiency, and SEC values were 94.62 ± 0.63%, 89.12 ± 0. 32%, and 687.57 ± 3.86 J/g.•Several aerobic aniline-degrading bacteria and anode-respiration bacteria were found to dominate the community of the anode biofilm.•The removal of azo dye degradation by-products was correlated with the o-bioanode and the BCO bacterial community structure.