Single-chamber differs from dual-chamber bioelectrochemical systems in wastewater treatment and methane recovery under combined exposure to microplastics and antibiotics

Hui Wang; Hui Zeng; Junhong Zhang; Qixing Zhou

doi:10.1016/j.jhazmat.2025.139175

Single-chamber differs from dual-chamber bioelectrochemical systems in wastewater treatment and methane recovery under combined exposure to microplastics and antibiotics

J Hazard Mater. 2025 Jul 8:496:139175. doi: 10.1016/j.jhazmat.2025.139175. Online ahead of print.

Authors

Hui Wang¹, Hui Zeng¹, Junhong Zhang¹, Qixing Zhou²

Affiliations

¹ MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Carbon Neutrality Science Center, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
² MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Carbon Neutrality Science Center, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China. Electronic address: zhouqx@nankai.edu.cn.

PMID: 40651382
DOI: 10.1016/j.jhazmat.2025.139175

Abstract

The coexistence of microplastics (MPs) and antibiotics in wastewater poses important threats to microbial ecosystems and methane recovery during anaerobic digestion (AD). This study systematically compares the methanogenic performance and microbial response of single- and dual-chamber bioelectrochemical systems (BES) (0.8 V) exposed to a mixture of MPs (10 mg/L) and antibiotics (1 mg/L). Results demonstrated that single-chamber BES significantly enhanced methanogenesis, achieving a 21.19 % increase in methane production compared to conventional AD, while dual-chamber BES exhibited limited activity due to ammonia inhibition and acetate accumulation. Meanwhile, pollutant exposure dramatically altered the functional enzyme activities and microbial community structure. Metagenomic analysis revealed that methane was primarily produced via the acetoclastic pathway mediated by Methanothrix, with electrical stimulation promoting direct interspecies electron transfer. Pollutant exposure drastically altered microbial communities, reducing Euryarchaeota and enriching fermentative bacteria (e.g., Proteiniphilum). Notably, antibiotic resistance genes (ARGs) increased across all systems, with electrode carriers amplifying ARGs proliferation. However, single-chamber BES showed superior resistance to horizontal gene transfer of ARGs. Key metabolic pathways (e.g., glycolysis, TCA cycle) were markedly inhibited, highlighting the cascading effects of pollutants on microbial energetics. These findings highlight the potential of single-chamber BES for treating co-contaminated wastewater, providing critical insights for optimizing BES configurations.

Keywords: Antibiotic resistance genes; Bioelectrochemical systems; Combined pollutant exposure; Microplastics; Wastewater treatment.