Evaluation of photocathode coupling-mediated hydroxychloroquine degradation in a single-chamber microbial fuel cell based on electron transfer mechanism and power generation

Abstract

A photocathode-microbial electrochemical coupling system (PC-MFC) using black phosphorus-doped titanium dioxide nanobelt (BP/TB) as a photocatalyst is constructed for the degradation of hydroxychloroquine (HCQ, used to treat COVID-19). The degradation efficiency of HCQ (100 mg/L) in coupling system is 73.7% within 8 h, higher than that of photocatalysis (69.5%), MFC (25.6%), and adsorption (9.6%). The photocathode coupling facilitates subsequent bioelectric treatment, resulting in complete degradation of HCQ (100 mg/L) within 96 h in PC-MFC, much higher than in MFC (51.1%). Illumination of PC-MFC significantly increases the cathodic abundance of Pseudomonadales ord. (from 1.83% to 66.30%), accumulates biomass, improves the electrochemical behaviors of photocathode and bioanode, and finally increases the maximum power from 241 to 280 mW/m 2 . The electron transfer pathways depende on nicotinamide adenine dinucleotide dehydrogenase , succinate dehydrogenase and terminal oxidase . The coupled system enhances the dechlorination reduction of HCQ and reduces the biotoxicity of its degradation pathway. PC-MFC represents a new strategy for the treatment and energy recovery of refractory organic compounds in wastewater. • A single-chamber microbial fuel cell with a coupled photocathode was constructed. • The system increased the removal of hydroxychloroquine (HCQ) by 52.0%. • The system facilitated electrochemical behaviors and electricity production. • Photocathode increased the abundance of Pseudomonadales ord. and enriched biomass. • The photocathode enhanced the dechlorination and reduced the toxicity of HCQ.

Identifiers

DOI

10.1016/j.jpowsour.2022.232625

Journal

Journal of Power Sources

Year

2023