Effect of poised cathodic potential on anodic ammonium nitrogen removal from domestic wastewater by air–cathode microbial fuel cells

• Published in: Bioresource technology Vol. 348; p. 126807
• Main Authors: Joel Koffi, N'dah, Okabe, Satoshi
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-03-2022
• Subjects: Air–cathode microbial fuel cells (MFCs); Ammonium Compounds; Anodic ammonium oxidation; Bioelectric Energy Sources; Bioelectrochemical ammonium nitrogen oxidation; Denitrification; Electrodes; Nitrogen - analysis; Poised cathodic potential; Waste Water; Bioelectrochemical ammonium nitrogen oxidation; Anodic ammonium oxidation; Air–cathode microbial fuel cells (MFCs); Poised cathodic potential
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2022.126807

•The effect of poised air–cathode potential on NH4+-N removal was investigated.•The NH4+-N removal rate of 150 ± 13 g-NH4+-N/m3/d was achieved at +0.7 V vs. SHE.•Poising the air–cathode increases the current, promoting anodic nitrification.•High NH4+-N removal was due to enhancing both anodic and aerobic NH4+-N oxidation.
Performances of anodic ammonia oxidation have been investigated for various bioelectrochemical systems at a wide range of poised anodic potentials in the literature. The effect of poised cathodic potential on ammonium nitrogen (NH4+-N) and total nitrogen (TN, sum of NH4+-N, NO2–-N, and NO3–-N) removal from domestic wastewater by single chamber air–cathode microbial fuel cells (MFCs) was investigated. Poising the air–cathode potential at +0.7 V vs. SHE significantly increased current generation (from 11 ± 1 mA to 22.8 ± 5 mA) and oxygen permeation into the MFC through the air–cathode (from 75.4 ± 1.2 g-O2/m3/d to 151 ± 3.7 g-O2/m3/d), which consequently resulted in a high NH4+-N removal rate of 150 ± 13 g-NH4+-N/m3/d and TN removal rate of 63 ± 16 g-TN/m3/d. These high NH4+-N and TN removal rates could be attributed to the enhancement of dual respiratory pathways: the electrode-assisted anodic and aerobic NH4+ oxidation.