Current advances of VOCs degradation by bioelectrochemical systems: A review

The volatile organic compounds (VOCs) impose severe environmental issues such as haze, photochemical smog, ozone depletion, and global warming. The degradation of VOCs in the gas phase is determined by the gas-liquid mass transfer and/or the microbial activity depending on the properties of the VOCs such as solubility, bioavailability, and toxicity. Bioelectrochemical systems (BESs), integrating microbial-electro-chemical removal mechanisms, have been intensively investigated for the organic compound removal in wastewater. In BESs, the interaction between the microbes and electrodes facilitates the electron transfer rate during the organic compound degradation and hence have a great potential to enhance the microbial activity. Currently, BESs are also under development for the refractory VOCs removal both in the liquid phase and gas phase. This review summarizes the current advances of the VOCs removal by BESs in terms of the mechanisms, pathway, removal efficiency, and coulombic efficiency. Furthermore, the challenges and future perspectives on the development of the efficient BESs for VOCs removal with a high coulombic efficiency are briefly discussed. It is believed that this review provides a new insight into the biological removal of VOCs.