High electricity generation and exhaust gas treatment enhancement using a microbial fuel cell of biological cathode equipped with conductive packing materials

Biotrickling filters (BTFs) designed for the treatment of volatile organic compounds (VOCs) have attracted much attention in the field of environmental engineering. As one of the main pollutants in VOCs, xylene is an aromatic hydrocarbon that poses a threat to human health. In this study, a biotrickling filter -microbial fuel cell (BTF-MFC) system was constructed to treat p-xylene by using a BTF filled with conductive packing materials as the biocathode for microbial fuel cell (MFC). The BTF-MFC showed good p-xylene removal performance even at high inlet concentrations. The elimination capacity reached 27.67 g/m3h at a 400 s empty bed residence time, and the removal efficiency reached 98.31% at a 300 s empty bed residence time. The conductive packing materials added to the BTF-MFC effectively promoted bacterial colonization, which as a result promoted p-xylene degradation and increased power output. The output voltage reached 725 mV, with a power density of 3.50 W/m2. The abundance of the genera Hydrogenophaga, Flavihumibacter, Chryseobacterium, and Mycobacterium, which have an excellent degradation capacity for aromatic compounds, increased during BTF-MFC operation.