A novel UV-assisted PEC-MFC system with CeO2/TiO2/ACF catalytic cathode for gas phase VOCs treatment

Chemosphere. 2020 Sep:255:126930. doi: 10.1016/j.chemosphere.2020.126930. Epub 2020 May 3.

Abstract

Emissions of volatile organic compounds (VOCs) air pollutants could worsen air quality and adversely affect human health, thus developing more efficient low-temperature VOCs removal techniques is desired. A novel continuous system integrating UV-assisted photo-electrochemical catalysis with microbial fuel cell (UV-assisted PEC-MFC) has been established for promoting removal of gaseous ethyl acetate or toluene and generating electricity simultaneously. In this system, CeO2/TiO2/ACF catalytic cathode is prepared and used for combination with bio-anode for accelerating cathodic reaction. This UV-assisted PEC-MFC system exhibits an excellent elimination capacity (EC) of ethyl acetate (∼0.39 g/m3, EC: ∼2.52 g/m3/h) or toluene (∼0.29 g/m3, EC: 1.89 g/m3/h) under close-circuit condition. Furthermore, an outstanding elimination capacity (EC: 28.04 g/m3/h) for high concentration toluene (∼4.10 g/m3) removal is obtained after toluene gas passes sequentially through the catalytic cathode then the bio-anode. This way of PEC degradation and biodegradation, avoids inhibition of exoelectrogens activity from toxicity of high concentration toluene. Simultaneously, the cell voltage of UV-assisted PEC-MFC system is stable at 0.11 V (vs. SCE) and 1.452×10-4 kWh is generated from treatment of toluene gas stream in 6 h duration time. The possible mechanism of VOCs removal in this novel system has been proposed and discussed. This study provides new technical basis for treating gaseous pollutants via integrating photo-electrochemical catalysis with electricity generating microbial fuel cell for energy conversion.

Keywords: CeO(2)/TiO(2)/ACF cathode; Electricity generation; Hydroxyl radical; PEC-MFC; VOCs removal.

MeSH terms

  • Air Pollutants / chemistry
  • Biodegradation, Environmental
  • Bioelectric Energy Sources
  • Catalysis
  • Electricity
  • Electrodes
  • Environmental Pollutants
  • Gases
  • Titanium
  • Toluene / chemistry
  • Ultraviolet Rays
  • Volatile Organic Compounds / chemistry*

Substances

  • Air Pollutants
  • Environmental Pollutants
  • Gases
  • Volatile Organic Compounds
  • titanium dioxide
  • Toluene
  • Titanium