电活性生物膜阳极构建及其对2,4,6-三氯酚同步降解和产电

Construction of highly active biofilm anode and its simultaneous electricity generation and degradation of 2,4,6-trichlorophenol

为实现氯酚(CPs)的高效降解和资源化利用,探究微生物燃料电池(MFC)体系优势功能菌,揭示生物降解路径.接种、驯化长春市南郊污水处理厂的厌氧活性污泥,获得生物膜阳极以构筑MFC-2,4,6-TCP体系,基于扫描电子电镜(SEM)、16S rRNA分析测序方法,考察生物膜阳极微生物的附着情况和优势菌种,基于电化学阻抗(EIS)、循环伏安(CV)和线性扫描伏安(LSV)等电化学分析手段,表征生物阳极的电化学性能和氧化还原能力.结果表明,生物膜阳极微生物种类丰富,其中Geobacter和Acinetobacter分别为MFC-2,4,6-TCP体系产电和降解驯化期的优势功能菌,体系最大输出电压可达0.55 V,最大功率密度为428.65 mW·m^(-2),对2,4,6-TCP的降解和矿化率可达97.5%和85.4%.随着MFC循环次数的增加,微生物代谢途径多样化,产电菌逐渐演替为协同菌,且优势功能菌对2,4,6-TCP降解的中间产物(环己醇),其毒性远低于氯酚或苯酚,更利于被微生物利用.该结果可为氯酚废水的实际处理提供新策略和技术参考.

In order to realize the high-efficient degradation and resource utilization of chlorophenols(CPs),the dominant functional bacteria of microbial fuel cell(MFC)system were explored,and the biological degradation pathways were revealed. Anaerobic activated sludge was inoculated and cultured in nutrient solution containing 2,4,6-trichlorophenol(2,4,6-TCP),and bio-anode was obtained to construct MFC-2,4,6-TCP system. The microbial attachment and structure on the electrode were investigated by scanning electron microscopy(SEM)and 16S rRNA sequencing,and the electrochemical performance and redox capacity of the electrode were characterized by electrochemical impedance spectroscopy(EIS),cyclic voltammograms(CVs)and linear sweep voltammetry(LSV). The results showed that the microbial species in the bio-anode were abundant,among which Geobacter and Acinetobacter were the dominant functional bacteria during the bioelectricity and biodegradation stages in MFC-2,4,6-TCP,respectively. The maximum output voltage of MFC-2,4,6-TCP system reached 0.55 V,and the maximum power density was 428.65 mW·m^(-2). 97.5% of2,4,6-TCP was degraded with highly dechlorination and mineralization efficiency(85.4%)by MFC-2,4,6-TCP system. With the increase of the MFC-2,4,6-TCP cycles,the microbial metabolic pathways were diversified,and the electrogenic bacteria gradually evolved into the synergistic bacteria.Moreover,the main intermediate product(cyclohexanol)was much less toxic than CPs or phenol,which was more favorable to be utilized by microorganisms. The results of this study can provide a new strategy and technical reference for the actual treatment of CPs wastewater.