Effect of micro electric field on cathode microbial diversity in the process of phenol degradation in microbial fuel cell

Abstract:

[Background] Phenol wastewater has attracted much attention as a kind of wastewater with strong toxicity and refractory degradation. At present, microbial fuel cell (MFC) have been widely used for the degradation of phenol wastewater. The power generation efficiency of MFC and the degradation efficiency of phenol are closely related to the microbial community in the reactor. [Objective] In order to improve the electricity generation effect of MFC and the degradability of harmful substances, it is necessary to explore the degradation of phenol in MFC and the structure of microbial community. [Methods] In open and closed circuit condition, high-performance liquid chromatography (HPLC) was used to test the removal rate of phenol by MFC; 16S rRNA gene high-throughput sequencing technology was used to analyze changes in the microbial community in the cathode compartment. [Results] The results showed that compared with open circuit control, the removal effect of phenol in closed circuit condition has been significantly improved. In addition, the species diversity of cathodic microorganisms has increased. Although the overall species abundance has decreased, the abundance of some electricity-producing and degrading bacteria has increased significantly, such as, Proteobacteria and Actinobacteria at the phylum level and Gammaproteobacteria at the class level. [Conclusion] The existence of the micro electric field promotes the growth of some functional microorganisms, which has a positive impact on the degradation of phenol and the power generation of MFC.