【摘要】 电极的结构和性质是影响生物电化学体系(BES)阴极反应效率的重要因素。以对氯硝基苯(4-CNB)为去除对象,研究了MnO2对BES阴极生物电还原水中4-CNB的强化作用。结果表明,使用碳电极原位还原KMnO4的方法能够在碳布(CP)表面生长具有连续均一三维片层结构的MnO2,且CP-MnO2电极对4-CNB的还原活性较CP电极更高;两种电极对4-CNB的去除均遵循一级反应动力学,CP-Mn O2能够更加有效地去除水中的4-CNB,其反应动力学常数是普通CP电极的1.47倍。MnO2对4-CNB生物电还原的强化作用主要是由于MnO2三维片层结构极大地增加了电极表面积,为电活性细菌和生物膜附着生长提供了更多的位点和空间,进而提高了生物膜密度;此外,MnO2的准电容特性通过Mn(Ⅳ)和Mn(Ⅲ)之间的快速转换提高了电子在界面上的转移速率。该法操作简单、绿色、成本低,在构建BES高效电极强化去除水中污染物效果方面有着很高的潜在应用价值。更多还原

【Abstract】 The electrode structure and property are the important factors that impact cathodic reaction efficiency of bioelectrochemical system( BES). The enhanced removal of 4-chloronitrobenzene( 4-CNB) in BES by Mn O2 was investigated. The results demonstrated that the in-situ reduction of KMn O4 by carbon electrode could achieve the growth of the continuous uniform three-dimensional structured Mn O2 on the surface of carbon paper( CP). The CP-Mn O2 electrode was more active than CP electrode for bioelectrochemical reduction of 4-CNB. The 4-CNB removal accorded with the first-order kinetics,and the kinetic coefficient of CP-Mn O2 electrode was 1. 47 times that of CP electrode,indicating that CP-Mn O2 electrode was more efficient in removal of 4-CNB. The enhanced performance mainly originated from the substantial increase in surface area caused by three-dimensional structure for increased local density of electrochemically active biofilm. Besides,the pseudo-capacitive property of Mn O2 also promoted the interfacial electron transfer between biofilm and electrode. This study provided a simple,green and cost effective method for fabrication of high-efficiency electrode for removal of pollutants in water.更多还原