Energy recovery of ethanolamine in wastewater using an air-cathode microbial fuel cell

• ETA was effectively degraded in air-cathode single-chamber MFC.
• COD of 91% was removed in the MFC whereas COD of 83% was treated in an open circuit experiment.
• The maximum power density of 240 mW m−2 was observed.
• Coulombic efficiency of 18.2% was obtained in the MFC.

Ethanolamine (ETA) is widely used as a metal corrosion inhibitor and for CO2 capture. The treatment of ETA in wastewater involves advanced oxidation or electrolysis, which requires excessive energy since it is a not readily biodegradable organic containing amine. In this study, a microbial fuel cell (MFC) for simultaneous ETA degradation and electricity generation was investigated. 80 mL of an air-cathode single-chamber MFC was designed to determine the degradation and by-products formation of ETA and the power density. The reactor was inoculated with return activated sludge taken from a local wastewater treatment plant. This system was able to remove 91% of chemical oxygen demand (COD) and 37% of ammonia when ETA was injected into the MFC. A maximum power density of 240 mW m−2 (7.65 mW m−3) and a Coulombic efficiency of 18.2% were obtained with the ETA-fed MFC. From the results, although further research is required to treat ammonium derived from ETA degradation and to improve the performance of the MFC, it was found that the MFC would be a promising technology for ETA wastewater treatment, as well as electricity production.