Improved bioelectricity production using potassium monopersulfate as cathode electron acceptor by novel bio-electrochemical activation in microbial fuel cell

摘要

Potassium monopersulfate (PMS) without a catalyst as cathode electron acceptor was first established to improve the electricity generation performance of a microbial fuel cell (MFC) in this study. The work investigated the performance with pure PMS (PPMS) and compound PMS (CPMS). The concentration and initial .pH of PMS had an effect on the electricity generation, which increased with higher PMS concentration and lower catholyte pH. In the PPMS-MFC system, the maximum voltage (0.972 V), power density (1637 W/m(3)), optimal exchange current density (2.000 A/m(3)) and minimum polarization impedance (Rp: 97.33 Omega) were reached at 10 mM PMS and pH 3.0. However, the maximum power density (8.60 W/m(3)) was exhibited at 70 mM PMS and pH 3.0 in the CPMS system. Additionally, high COD removals of 99.41% and 98.71% in anode chambers were obtained in the two systems, respectively. Sulfate radicals (SO4 center dot-) and hydroxyl radicals (center dot OH) played significant roles in the PPMS-MFC, while HCIO was also a contributor in addition to SO4 center dot- and center dot OH in the CPMS-MFC. Furthermore, SO(4)(center dot- )and center dot OH was generated in situ in the cathode to promote the reduction reaction. The inorganic anion had different effects on electricity generation. Finally, while energy was recovered, rhodamine B (RhB) was added to the cathode chamber and then removed successfully in PPMS-MFC system. This work confirmed that only PMS could be activated by bio-electrochemical method, which is an energy-saving, environmentally friendly and effective activation approach, and thus, it could be used as an efficient acceptor in a MFC. (C) 2019 Elsevier B.V. All rights reserved.