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Updated: May 13, 2026
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Mesocosm-Scale Constructed Wetland Design for Wastewater Treatment
Published on: May 2, 2025
Fe-C Micro-Electrolysis Driven Dyeing Wastewater Purification in Constructed Wetlands
Shiwen Xu1, Qingju Hao1,2, Xiaoya Chen1
1Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, China.
Summary
Fe-C micro-electrolysis in constructed wetlands significantly improved textile dyeing wastewater treatment and reduced greenhouse gas emissions. This novel approach enhances microbial activity for efficient pollutant removal and low-carbon industrial wastewater remediation.
Area of Science:
- Environmental Science
- Environmental Engineering
- Microbiology
Background:
- Textile dyeing wastewater presents environmental challenges due to high chemical oxygen demand (COD), persistent organic compounds, and intense color.
- Conventional treatment methods often struggle with efficiency and can contribute to greenhouse gas emissions.
Purpose of the Study:
- To investigate the effects of Fe-C micro-electrolysis on textile dyeing wastewater treatment.
- To assess the impact on greenhouse gas emissions and microbial community structure.
- To compare different configurations of intermittently aerated vertical-flow constructed wetlands (CWs).
Main Methods:
- Four CW configurations were tested: gravel-based (GCW), biochar-amended (BCW), zero-valent iron (ZVI) amended (ZCW), and a combined biochar-ZVI system (ICW).
- Wastewater treatment efficiency (dyes, COD, NH4+-N, TP), greenhouse gas (GHG) emissions (CH4, N2O), and microbial community diversity and function were analyzed.
- Key microbial ratios (pmoA/mcrA, nosZ/(nirK+nirS)) and functional gene abundances were quantified.
Main Results:
- All CWs effectively removed dyes (>94%), COD (>81%), and nitrate-nitrogen (>94%).
- The integrated system (ICW) showed superior performance in NH4+-N (>85%) and TP (79.75%-96.46%) removal.
- ICW achieved the lowest integrated global warming potential (GWP), with a 62.75% reduction compared to GCW, due to suppressed CH4 and N2O emissions.
- Microbial analysis revealed higher richness and diversity in ICW, with enriched functional genera for dye degradation, denitrification, and electrogenesis.
Conclusions:
- Fe-C micro-electrolysis, particularly in the combined biochar-ZVI system (ICW), offers efficient and stable treatment for textile dyeing wastewater.
- This approach significantly mitigates greenhouse gas emissions by modulating microbial pathways involved in methanogenesis and denitrification.
- The synergistic effect of biochar and ZVI optimizes microbial community structure and function, providing a novel low-carbon solution for industrial wastewater remediation.
