Abstract: Electrochemistry(electro-assisted)was introduced to the microbial reduction of PCP in order to resolve the lack of electron donor and the slow reduction rate.It was found that the PCP degradation efficiency of 97% in the electro-assisted microbial system was higher than the sum of that of 62% in the microbial system and that of 26% in the electrochemical system by about 10%.The cyclic voltammetry(CV)curves of the PCP reduction degradation in the electro-assisted microbial system and in the electrochemical system were compared.There were obvious redox peaks in the cyclic voltammetry curves of the electro-assisted microbial system and the electron transfer rate was 0.856 m穝^-1,the electron transfer coefficient was 2.024 in a two-electron transfer process,which conformed to the biodegradation characteristics.The electron given by the electric field did accelerate the electron transfer during the microbial respiration.There was reverse electronic transfer between the electrodes,cytochrome c,cty穊c1,NAD and pollutants in the electro-assisted microbial system and the long-range electron transfer processes of multiphase interface between the electrode,microorganisms and pollutants were implemented. The study provides a new concept of electrochemical synergy with microbial reduction for environmental pollution control.

Key words: electro-assisted microbial system, PCP, cytochrome c, long-range electron transfer, reverse transfer

摘要： 针对微生物还原降解五氯酚(PCP)缺乏电子供体及过程缓慢的问题,将电化学(电辅助)引入微生物还原降解过程。研究发现电辅助微生物体系的降解效率为97%,这比微生物体系(降解效率为62%)和电化学体系(降解效率为26%)的加和高约10%。对比研究了电辅助微生物体系和电化学体系对PCP还原降解的循环伏安曲线,结果表明:电辅助微生物体系的循环伏安曲线上存在明显的氧化还原峰,电子传递速率为0.856 m·s^-1,电子传递系数为2.024,为两电子传递过程,符合生物降解规律,证实了电辅助加速了微生物降解过程的电子传递速率。电辅助微生物体系中存在着电极、细胞色素c、cty·bc1、NAD和污染物间的逆向电子传递途径,可实现电极-微生物-污染物间多相界面的长程电子传递过程。该研究为环境污染治理提供了一种电辅助与微生物协同作用的新理念。

关键词: 电辅助微生物, 五氯酚, 细胞色素c, 长程电子传递, 逆向传递