Enhance the removal of pyrene by 3,4-ethylene dioxythiophene modified electrode in microbial electrochemical system

In this study, the conductive polymer (3,4-ethylene dioxythiophene, PEDOT) was utilized to modify the anode of the sediment microbial electrochemical system, resulting in improved electrical properties and enhanced removal of polycyclic aromatic hydrocarbons pyrene from sediments. The results indicated that the capacitance of the modified anode increased by 94.5 F, the internal resistance decreased by 23.67 Omega, and the maximum output voltage of the close circuit system increased by 264 mV compared to the unmodified anode close circuit system with the external resistance of 500 Omega. The removal efficiencies of pyrene by the modified anode system were found to be 85.04 %, which represented an increase of 18.06 % over that of the unmodified anode system. The distribution of microbial community structure on the anode surface indicated that the modification of the anode by PEDOT enriched its surface with a relatively higher abundance of electroactive microorganisms and degradation-dominant microorganisms. Combined with the modified anode's larger capacitance and smaller internal resistance, a greater number of electrons were utilized for the redox reaction of pyrene under the mediation of microorganisms, thereby promoting the removal of pyrene from sediments.