Optimized feeding schemes of heterotrophic anodic denitrification coupled with cathodic phosphate recovery from wastewater using a microbial fuel cell

Abstract

Enhanced water quality standards and increasing resource scarcity have prompted extensive research into low-cost nitrogen removal and phosphate recovery from wastewater. Microbial fuel cells (MFCs) offer a viable solution by simultaneously removing nitrogen, recovering phosphorus, and generating electrical energy. This study employed MFCs to achieve simultaneous nitrogen removal and phosphorus recovery, investigating the impact of different feeding schemes. The experimental results indicated that replacing the entire anode chamber solution and recycling the anode effluent to the cathode chamber effectively prevented the accumulation of nitrifying bacteria while achieving the highest pollutant removal performance. Under closed circuit conditions, the system consistently maintained low nitrite concentrations, achieving an average nitrate removal efficiency of 68.09 ± 1.86 % and phosphate recovery efficiency of 83.46 ± 5.30 %. Furthermore, this feeding scheme facilitated microbial growth and reproduction while also improving operational convenience. The study utilized metagenomics and other technologies to comprehensively analyze the system's operation mechanism and reasons for its excellent performance.