Efficient bioanode from poultry feather wastes-derived N-doped activated carbon: Performance and mechanisms

Abstract

Bioelectrochemical systems have gained great interest as a viable wastewater treatment and energy recovery technology. How to achieve the efficient interfacial electron transfer from microbes to the electrode and reduce the cost are challenges of bioelectrochemical systems. This study demonstrated that the goose feather-derived N-doped activated carbon could be adopted as the effective anode modifier to improve the bioanode performance of bioelectrochemical systems. Various electrochemical characterizations showed that both the electrochemical activity and electron transfer efficiency of the electrodes were improved after modification with the goose feather-derived N-doped activated carbon. By using Shewanella oneidensis MR-1 inoculated bioelectrochemical systems with the goose feather-derived N-doped activated carbon-modified anode, a current density of 0.96 ± 0.03 A/m2 was achieved, which was about 2 times higher than that without modification. Further analysis revealed a simultaneous enhancement of direct and flavins-mediated extracellular electron transfer after the modification with the goose feather-derived N-doped activated carbon. This enhanced extracellular electron transfer could be not only attributed to the intense interaction between cytochromes OmcA/MtrC and the goose feather-derived N-doped activated carbon, but also due to the improved flavins redox reaction on the goose feather-derived N-doped activated carbon-modified anode surface. This study broadens the recipe of bioanode of BESs via rational use of natural solid waste materials.