Greywater and bacteria removal with synchronized energy production in photocatalytic fuel cell based on anodic TiO2/ZnO/Zn and cathodic CuO/Cu

Sze-Mun Lam; Jin-Chung Sin; Hua Lin; Haixiang Li; Honghu Zeng

doi:10.1016/j.chemosphere.2019.125565

Greywater and bacteria removal with synchronized energy production in photocatalytic fuel cell based on anodic TiO₂/ZnO/Zn and cathodic CuO/Cu

Chemosphere. 2020 Apr:245:125565. doi: 10.1016/j.chemosphere.2019.125565. Epub 2019 Dec 16.

Authors

Sze-Mun Lam¹, Jin-Chung Sin², Hua Lin³, Haixiang Li³, Honghu Zeng⁴

Affiliations

¹ College of Environmental Science and Engineering, Guilin University of Technology, Guilin, 541004, China; Guangxi Key Laboratory of Theory and Technology for Environmental Pollution Control, Guilin University of Technology, Guilin, 541004, China; Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst area, Guilin University of Technology, Guilin, 541004, China; Department of Environmental Engineering, Faculty of Engineering and Green Technology, Universiti Tunku Abdul Rahman, 31900, Kampar, Perak, Malaysia. Electronic address: lamsm@utar.edu.my.
² College of Environmental Science and Engineering, Guilin University of Technology, Guilin, 541004, China; Guangxi Key Laboratory of Theory and Technology for Environmental Pollution Control, Guilin University of Technology, Guilin, 541004, China; Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst area, Guilin University of Technology, Guilin, 541004, China; Department of Petrochemical Engineering, Faculty of Engineering and Green Technology, Universiti Tunku Abdul Rahman, 31900, Kampar, Perak, Malaysia.
³ College of Environmental Science and Engineering, Guilin University of Technology, Guilin, 541004, China; Guangxi Key Laboratory of Theory and Technology for Environmental Pollution Control, Guilin University of Technology, Guilin, 541004, China; Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst area, Guilin University of Technology, Guilin, 541004, China.
⁴ College of Environmental Science and Engineering, Guilin University of Technology, Guilin, 541004, China; Guangxi Key Laboratory of Theory and Technology for Environmental Pollution Control, Guilin University of Technology, Guilin, 541004, China; Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst area, Guilin University of Technology, Guilin, 541004, China. Electronic address: zenghonghu@glut.edu.cn.

PMID: 31855765
DOI: 10.1016/j.chemosphere.2019.125565

Abstract

An approach that can recuperate of energy from wastewater treatment process is highly necessitate and would help to surmount the both environmental pollution and energy crisis issues. A photocatalytic fuel cell (PFC) employing an anodic TiO₂/ZnO/Zn and a cathodic CuO/Cu has been applied to degrade the raw greywater, which realized advanced organics destruction, bacteria disinfection, and synchronously electricity production. The improved photocatalytic performance has been observed when the cell was incorporated with anodic TiO₂/ZnO/Zn under UV and sunlight irradiation due to the enhanced electric field conductivity of the catalysts and heterojunction interface of TiO₂. In the constructed UV-activated PFC system, the electricity production capability was observed with the measured voltage and power density of 868 mV and 0.0172 mW cm^-2, respectively. Advanced chemical oxygen demand (COD) removal efficiency of greywater achieved a 100% completion within 60 min of light irradiation. The Escherichia coli (E. coli) colonies decreased significantly and accounted ∼99% disinfection efficiency. Moreover, the photoelectrochemical and photoluminescence (PL) experiments elucidated that the charge carrier separation efficiency were higher when TiO₂ was coupled to ZnO. The organic matter elimination principle was assessed by radical trapping experiment, and the findings indicated that the hydroxyl (OH) radical and hole (h⁺) appeared as major functions in the reaction. The stable cycle operation of the cell has been also obtained owing to the stable and film-type materials of anodic material. This performance was among the highest documented for PFC using real wastewater effluent as the fuel source.

Keywords: Bacteria disinfection; Electricity production; Greywater; Photocatalytic fuel cell; TiO(2)/ZnO/Zn photoanode.

MeSH terms

Bacteria
Bioelectric Energy Sources
Biological Oxygen Demand Analysis
Catalysis
Copper
Electricity
Electrodes
Escherichia coli
Waste Disposal, Fluid / methods*
Wastewater / chemistry
Wastewater / microbiology*
Zinc
Zinc Oxide / chemistry

Substances

Waste Water
Copper
Zinc
Zinc Oxide
cupric oxide