Simultaneous Degradation of Penoxsulam with Power Generation in Microbial Fuel Cells

The widespread use of penoxsulam has increased the potential for environmental risks. In this study, a microbial fuel cell (MFC) was investigated and optimized for degradation of penoxsulam and corresponding power generation performance. Of the electricity producing bacteria tested, Shewanella putrefaciens was found to be the most suitable, and reached a maximum power of 260.4 mW/m(2) along with a penoxsulam degradation efficiency of 95%. MFC electrical performance was greatly enhanced by increasing the anode carbon felt surface area from 5 to 20 cm(2), which raised the MFC electrical power from 90.3 to 240.3 mW/m(2) and increased the penoxsulam degradation efficiency in parallel. The initial penoxsulam concentration in the reaction system influenced MFC power generation, where higher initial penoxsulam concentrations inhibited microbial activity, decreased the MFC power performance, and reduced the penoxsulam degradation efficiency. In addition, the MFC reaction system pH influenced MFC electrical performance, and adjusting the pH to 8 increased the peak voltage and power density to 0.687 V and 264.8 mW/m(2), respectively. S. putrefaciens secretes soluble compounds to mediate electron transfer and the addition of Riboflavin (RF) increases the charge transfer efficiency. Our findings provide a basis for revealing the mechanism by which organic contaminants are degraded in MFCs, and demonstrate the feasibility of MFCs for efficient penoxsulam degradation and power generation.