Micro-electric field-associated restructuring of bacterial communities enhances wastewater purification in constructed wetlands

Abstract

Summary To improve microbial activity and shock resistance in constructed wetlands (CWs), we established micro-electric field (MEF) enhanced CW systems to investigate their regulatory effects on domestic sewage treatment performance and bacterial communities. The results showed that MEF significantly improved the removal efficiencies of TP (16.97%–17.13%), NH4+-N (16.32%–28.93%), and COD (28.55%–53.81%). MEF also enhanced bacterial α diversity (Chao1, Shannon, Simpson) and altered community structure, with significant enrichment of Pseudomonadota and Bacteroidota that positively correlated with pollutant removal. Network analysis indicated that the MEF increased microbial network complexity and connectivity, and promoted competitive interactions within the community. Functional prediction revealed that MEF upregulated key pathways involved in carbon metabolism and nitrogen metabolism. We hypothesize that the MEF improves pollutant removal performance and stability in CWs by optimizing micro-environmental conditions and promoting a more diverse and functional microbial community. This work provides a microbiological foundation for developing energy-efficient, low-carbon wetland technologies.