Treatment of Coal Tar Wastewater and Electricity Production Using a Microbial Fuel Cell

Coal tar wastewater treatment and electricity production using a microbial fuel cell (MFC) is reported for the first time in this paper. During the test, removal of COD and sulfate, pH variation, voltage output, and power density were monitored for a 24-day period. In addition, degradation of specific coal tar compounds and changes in concentrations of other chemical elements were examined before and after the MFC treatment. Results showed that pH decreased from 7.8 to 6.95 while 87.9% of COD and 57.1% of sulfate removal efficiencies were achieved. Concentration of almost all the chemical elements decreased as a result of the MFC treatment except for boron and arsenic. In particular, sulfur removal efficiency was 41.1%. Specific organic compounds identified in the wastewater by GUMS included phenol, benzonitrile, 2- and 3- methyl phenol, and naphthalene among others. Coal tar compounds such as phenol and naphthalene were not detected after the MFC treatment. Maximum voltage output and power density were 543 mV and 4.54 mW/m(2), respectively. These results suggest that MFC could be a cost-effective treatment method for coal tar wastewaters.