生物电化学系统对河道沉积物中抗生素的强化去除

生物电化学系统已被证明可以有效降解废水或污泥中的抗生素，但对于河道沉积物中抗生素降解效果的研究还十分有限.本研究以河道沉积物为底物，考察了沉积物中本底抗生素在微生物电解池（microbial electrolysis cell， MEC）和微生物燃料电池（microbial fuel cell， MFC）中的去除、迁移和降解效率，以及反应器运行期间的电化学性能和微生物种群结构变化.结果显示，MEC和MFC均可以强化沉积物中抗生素的去除，喹诺酮类抗生素和四环素类抗生素中的CTC的去除是向上覆水中迁移与生物电化学降解共同作用的结果，而大环内酯类抗生素和四环素类抗生素中的TC和OTC的去除主要是依靠生物电化学降解作用.TC和OTC在MEC中的降解效率分别比MFC高出82.6%和29.5%，而MFC对大环内酯类抗生素的降解效率比MEC高27.6%~40.6%.电化学性能测试结果显示，以河道沉积物为底物的MFC内阻较大导致其功率密度相对较低，但MFC阳极比MEC阳极表现出了更好的氧化效果.微生物种群结构变化分析发现，门水平上的Proteobacteria及其对应的纲水平上的Deltaproteobacteria和Gammaproteobacteria可能对抗生素的强化去除起到了主要的积极作用，而且MFC阳极比MEC更容易富集Proteobacteria.

Enhanced removal of antibiotics from the river sediments by bioelectrochemical systems

Bioelectrochemical system has been demonstrated to degrade antibiotics in wastewater or sewage sludge effectively, but research on the degradation of antibiotics in river sediments were still very limited. In this study, microbial electrolysis cell (MEC) and microbial fuel cell (MFC) reactors were constructed using river sediment as the substrate to investigate the removal, migration and degradation of antibiotics in sediments, as well as the variation of electrochemical characteristics and microbial community structures. Results showed that both MEC and MFC enhanced the removal of antibiotics in sediments. The removal of quinolones and CTC depended on both migration and biodegradation, while the removal of macrolides, TC and OTC was mainly due to the bioelectrochemical degradation. The degradation efficiencies of TC and OTC in MEC were 82.6% and 29.5% higher than those in MFC, respectively, while the degradation efficiency of macrolides in MFC was 27.6%~40.6% higher than that in MEC. The electrochemical analysis results showed that the power density of MFC with sediments as the substrate was relatively low due to the large internal resistance, but the anode of MFC showed better oxidation function than MEC. Microbial analysis showed that Proteobacteria and its corresponding class Deltaproteobacteria and Gammaproteobacteria were likely to play an important role in the enhanced removal of antibiotics, and MFC were easier to enrich Proteobacteria on anodes than MEC.