Enhanced performance of microbial fuel cell with electron mediators from tetracycline hydrochloride degradation.

Abstract

Tetracycline hydrochloride (TCH) is a typical antibiotic pollutant with high toxicity and persistence. The degradation of TCH and the generation of the associated electron mediator in a dual chamber microbial fuel cells (MFCs) were studied. The results of liquid chromatography revealed that TCH could be effectively removed (>93%) in MFCs mode. The maximum COD removal was 88.14 ± 1.47% in MFCs while it was 69.57 ± 1.36% in open circuit MFCs. According to cyclic voltammetry, the presence of the relevant redox peaks clearly suggested that the intermediates from TCH degradation could act as endogenous electron mediator. The highest power density of 120.02 ± 2.76 mW/m² and the lowest internal resistance of 18.68 Ω were achieved in MFC with 2 mg/L of TCH. Microbial community analysis illustrated that Bacteroides, Comamonas, Clostridium_sensu_stricto, Desulfovibrio and Geobacter were enriched and played a dominant role in TCH degradation and power generation. Electrochemical active bacteria had certain tolerance to TCH and the inhibiting threshold value of TCH was below 5 mg/L. This study provided a new thinking that low concentration of TCH could produce electron mediators to improve the performance of MFC system.

Key findings

• ▸The results of liquid chromatography revealed that TCH could be effectively removed (>93%) in MFCs mode.
• ▸47% in MFCs while it was 69.
• ▸36% in open circuit MFCs.
• ▸76 mW/m² and the lowest internal resistance of 18.
• ▸68 Ω were achieved in MFC with 2 mg/L of TCH.

Keywords

Identifiers

DOI

10.1016/j.envres.2021.112605

PubMed

34958780

Journal

Environmental research

Year

2022