Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) bioanodes in Co-doped modified microbial fuel cell promote sulfamethoxine degradation with high enrichment of electroactive bacteria and extracellular electron transfer

Microbial fuel cell (MFC) is a new renewable energy technology, which has a wide range of applications. In this paper, the refractory organic matter sulfamethoxazole (SMX) was degraded by MFC technology, and the electricity generation performance was analyzed in detail. Since Ni and Fe ions can promote electron transfer, the presence of S ions can enhance the biocompatibility of the material, in this study, nano-ferro nickel sulfide (NiFe2S4) was prepared by hydrothermal method, and co-doped with ferro oxide (Fe3O4) nanoparticles to modify the poly (3,4-ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT: PSS) hydrogel served as the bioanode of MFC. Through high throughput results, we found the enriched electro producing bacteria Desulfuromonas and Fe-S cluster oxidoreductase, proving that bimetallic sulfides have good synergistic effect with metal oxides, which can provide more active sites and accelerate the EET process. The maximum power density obtained as a bioanode in MFC was 3.67 W/m3. During degradation of SMX, the maximum power density was 2.39 W/m3. At the same time, the degradation efficiency of SMX reached 93.78 %, and the chemical oxygen demand (COD) removal rate was 32.52 %. This provides a valuable reference for the degradation of refractory organic compounds such as antibiotic SMX, and also provides multi-dimensional thinking for renewable energy technologies.