Simultaneous nutrient and carbon removal and electricity generation in self-buffered biocathode microbial fuel cell for high-salinity mustard tuber wastewater treatment

Abstract

Mustard tuber wastewater (MTWW) was used as both anolyte and catholyte in biocathode microbial fuel cell (BMFC). The results showed simultaneous nutrient and carbon removal and electricity generation were realized in BMFC. Excellent Chemical Oxygen Demand (COD) removal occurred in both anode (>90%) and cathode (>91%). Concerning nutrient removal, it was mainly removed in cathode. The maximum total phosphorus (TP) removal could reach 80.8 ± 1.0% by biological action. Simultaneous nitrification and denitrification (SND) was realized in cathode. The bacteria involved in nitrification were Nitrosomonas and SM1A02. Oceanimonas and Saprospiraceae_uncultured (anaerobic denitrifier), Thauera, Stenotrophomonas, Flavobacterium and Marinobacter (aerobic denitrifier), and Thioalkalispira (autotrophic denitrifier) were responsible for denitrification. Considering slight variation of anode and cathode pH, it could be concluded that MTWW was adequately self-buffered when used as electrolyte. Furthermore, electricity generation decreased with cathodic dissolved oxygen (DO) declining. These findings provide a novel method for MTWW resourceful treatment.