Microbial fuel cell-driven alkaline thermal hydrolysis for pretreatment of wastewater containing high concentrations of tetracycline in the cathode chamber
Journal
Journal of Environmental Chemical Engineering
Journal Volume
9
Journal Issue
1
Date Issued
2021
Author(s)
Abstract
Wastewater containing high concentrations of antibiotics may inhibit the biological treatment processes, and it could also result in an increase in antibiotic resistant genes in the biological treatment system, causing risks in the environmental waters. Therefore, in this study, taking advantage of the unstable characteristics of tetracycline in alkaline conditions, dual-chamber microbial fuel cells (MFCs) were coupled with the heater to drive the alkaline thermal hydrolysis of tetracycline in the cathode chamber, making tetracycline degradation without contact with microorganisms in the anode chamber. It was observed that tetracycline degradation rates under closed circuit conditions were faster than those under open circuit conditions due to the rising pH in the cathode chamber of closed circuit MFCs, and the temperature increase could result in a decrease in half-life of tetracycline degradation. The TOC analysis showed that most TOC was not removed after 48 h reaction, suggesting tetracycline was mainly transformed to byproducts in the cathode chamber. High resolution mass spectrometry identified the transformation products resulting from the alkaline thermal hydrolysis of tetracycline, and the minimum pharmacophore of tetracycline was altered, which would lead to the loss of antibacterial activity. Microtox tests confirmed the reduction in the toxic effect of tetracycline to luminescent bacteria after treatment in the cathode chamber. Our results have demonstrated the effective degradation of tetracycline using MFC-driven alkaline thermal hydrolysis, which will have potential to be a pretreatment process to assist the subsequent biological treatment processes to destroy high concentrations of antibiotics in the wastewater. ? 2020 Elsevier Ltd.
Subjects
Alkalinity; Antibiotics; Biochemical engineering; Biodegradation; Biological water treatment; Cathodes; Degradation; Hydrolysis; Mass spectrometry; Wastewater treatment; Anti-bacterial activity; Antibiotic-resistant genes; Biological treatment process; Biological treatment systems; Closed circuit conditions; High resolution mass spectrometry; Microbial fuel cells (MFCs); Open circuit conditions; Microbial fuel cells
Type
journal article