Effect of Temperature on Nitrogen Removal and Electricity Generation of a Dual-Chamber Microbial Fuel Cell

Microbial fuel cells (MFCs) have gained increasing attention as an effective pathway for wastewater treatment and electrical energy recovery. In this study, the pollutant removal, N2O production, and electricity generation at different temperatures (25–45 °C) in a dual-chamber MFC were investigated. The optimal temperature for pollutant removal and electricity generation was 35 °C. The results showed that maximal removal efficiencies of chemical oxygen demand (COD), ammonium (NH4+), and total nitrogen (TN) were 73.98 ± 0.92%, 99.24 ± 0.85%, and 8.28 ± 0.45%, respectively. The maximum of nitrous oxide (N2O) was 4.27 ± 0.11 mg L−1 at 35 °C. Meanwhile, the maximum of power density, current density, and coulombic efficiency (CE) were 0.54 W m−3, 6.51 A m−3, and 8.12 ± 0.04%, respectively. The results indicate that MFC is a promising technology for simultaneous pollutant removal and electricity generation in temperate regions. Moreover, microbial community analysis suggested that the dominant reaction in the cathode may include aerobic nitrification, autotrophic denitrification, heterotrophic denitrification (aerobic and anoxic), reduction of oxygen, and nitrogen fixation.