Journal Article

Simultaneous removal of heavy metals and bioelectricity generation in microbial fuel cell coupled with constructed wetland: an optimization study on substrate and plant types

Zhang, Qingyun, Xu, Dayong, Liu, Tingting, Wang, Lu, Tao, Zhengkai

2022

Overview

A microbial fuel cell coupled with constructed wetland (CW-MFC) was built to remove heavy metals (Zn and Ni) from sludge. The performance for the effects of substrates (granular activated carbon (GAC), ceramsite) and plants ( Iris pseudacorus , water hyacinth ) towards the heavy metal treatment as well as electricity generation was systematically investigated to determine the optimal constructions of CW-MFCs. The CW-MFC systems possessed higher Zn and Ni removal efficiencies as compared to CW. The maximal removal rates of Zn (76.88%) and Ni (66.02%) were obtained in system CW-MFC based on GAC and water hyacinth (GAC- and WH-CW-MFC). Correspondingly, the system produced the maximum voltage of 534.30 mV and power density of 70.86 mW·m −3 , respectively. Plant roots and electrodes contributed supremely to the removal of heavy metals, especially for GAC- and WH-CW-MFC systems. The coincident enrichment rates of Zn and Ni reached 21.10% and 26.04% for plant roots and 14.48% and 16.50% for electrodes, respectively. A majority of the heavy metals on the sludge surface were confirmed as Zn and Ni. Furthermore, the high-valence Zn and Ni were effectively reduced to low-valence or elemental metals. This study provides a theoretical guidance for the optimal construction of CW-MFC and the resource utilization of sludge containing heavy metals.

• Publisher: Springer Berlin Heidelberg,Springer Nature B.V
• Subject: Activated carbon / Activated sludge / Aquatic plants / Aquatic Pollution / Artificial wetlands / Biochemical fuel cells / Bioelectric Energy Sources / Bioelectricity / constructed wetlands / Construction / Earth and Environmental Science / Ecotoxicology / Eichhornia crassipes / electric potential difference / Electricity / electricity generation / Electrodes / Environment / Environmental Chemistry / Environmental Health / Environmental science / Floating plants / Fuel cells / Fuel technology / Heavy metal removal / Heavy metals / Iris pseudacorus / Metals / Metals, Heavy / microbial fuel cells / Microorganisms / Optimization / Plant roots / Research Article / Resource utilization / Roots / Sludge / Substrates / Waste Water / Waste Water Technology / Water hyacinths / Water Management / Water Pollution Control / Wetlands / Zinc