Accelerated azo dye degradation and concurrent hydrogen production in the single-chamber photocatalytic microbial electrolysis cell.
The single-chamber microbial electrolysis cell constructed with a TiO2-coated photocathode, termed photocatalytic microbial electrolysis cell (PMEC), was developed to accelerate methyl orange (MO) degradation and concurrent hydrogen (H2) recovery under UV irradiation. Results showed that faster MO decolorization rates were achieved from the PMEC compared with those without UV irradiation or with open circuit. With increase of MO concentrations (acetate as co-substrate) from 50 to 300mg/L at an applied voltage of 0.8V, decolorization efficiencies decreased from 98% to 76% within 12h, and cyclic H2production declined from 113 to 68mL. As the possible mechanism of MO degradation, bioelectrochemical reduction, co-metabolism reduction, and photocatalysis were involved; and degradation intermediates (mainly sulfanilic acid and N,N-dimethylaniline) were further degraded by OH generated from photocatalysis. This makes MO mineralization be possible in the single-chamber PMEC. Hence, the PMEC is a promising system for dyeing wastewater treatment and simultaneous H2production.
School of Environmental Science & Engineering, Guangxi University, Guangxi Colleges and Universities Key Laboratory of Environmental Protection, Nanning 530004, China. Electronic address: houyp@gxu.edu.cn.
Yanping
Y
Hou
Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
Renduo
R
Zhang
School of Environmental Science & Engineering, Guangxi University, Guangxi Colleges and Universities Key Laboratory of Environmental Protection, Nanning 530004, China.
Zebin
Z
Yu
School of Environmental Science & Engineering, Guangxi University, Guangxi Colleges and Universities Key Laboratory of Environmental Protection, Nanning 530004, China.
Lirong
L
Huang
School of Environmental Science & Engineering, Guangxi University, Guangxi Colleges and Universities Key Laboratory of Environmental Protection, Nanning 530004, China.
Yuxin
Y
Liu
School of Environmental Science & Engineering, Guangxi University, Guangxi Colleges and Universities Key Laboratory of Environmental Protection, Nanning 530004, China.
Zili
Z
Zhou
D000814:Aniline Compounds / Q000737:chemistry / Q000378:metabolism; D001391:Azo Compounds / Q000032:analysis / Q000378:metabolism*; D002384:Catalysis; D004396:Coloring Agents / Q000032:analysis / Q000378:metabolism*; D004566:Electrodes; D004572:Electrolysis; D006859:Hydrogen / Q000378:metabolism; D014025:Titanium / Q000737:chemistry; D014466:Ultraviolet Rays; D062065:Wastewater / Q000382:microbiology; D018508:Water Purification / Q000379:methods*
D000814:Aniline Compounds; D001391:Azo Compounds; D004396:Coloring Agents; D006859:Hydrogen; D014025:Titanium; D062065:Wastewater; C009495:titanium dioxide; C100258:methyl orange; C015157:N,N-dimethylaniline
Azo dye degradation; Degradation mechanism; Hydrogen production; Microbial electrolysis cell; Photocatalysis