Degradation of nitrobenzene-containing wastewater by a microbial-fuel-cell-coupled constructed wetland

A single chamber membrane-less air cathode microbial fuel cell coupled constructed wetland (MFC-CW) was constructed to treat nitrobenzene-containing wastewater and generate electricity simultaneously. Three devices of blank control (CK), microbial fuel cell (MFC) and MFC-CW were investigated. The inherent relationship between substrate degradation and electricity generation were evaluated by the electronic characteristics. The maximum voltage of MFC-CW was obtained at the electrode spacing of 13 cm. The maximum power density of MFC and MFC-CW were 0.59 and 1.53 mW/m2 respectively. The maximum nitrobenzene removal rate of 92.89% was attained in the MFC-CW when the concentration ratio of nitrobenzene to chemical oxygen demand (COD) was 1:16 with hydraulic retention time at 24 h. The COD removal rate was between 67.92% and 78.30%, and the MFC-CW was efficient for COD degradation.