Recent advances in constructed wetland‐microbial fuel cells for simultaneous bioelectricity production and wastewater treatment: A review

Summary The coupling of constructed wetlands (CWs) to microbial fuel cells (MFCs) has turned out to be a source of renewable energy for the production of bioelectricity and for the simultaneous wastewater treatment. Both technologies have an aerobic zone in the air‐water interface and an anaerobic zone in the lower part, where the anode and the cathode are strategically placed. This hybridization is a promising bioelectrochemical technology that exerts a symbiosis between plant‐bacteria in the rhizosphere of an aquatic plant, converting solar energy into bioelectricity through the formation of root exudates as an endogenous substrate and a microbial activity. The difference between CW‐MFC and MFC conventional lies in the bioelectricity and substrate production in situ, where exogenous substrates are not required for example wastewater. However, CW‐MFC can take organic content present in wastewater, promoting the removal of some pollutants. Different areas that comprise the study of a CW‐MFC have been explored, including the structures and their operation. This review aims to provide concise information on the state of the art of CW‐MFC systems, where a summary on important aspects of the development of this technology, such as bioelectricity production, configurations, plant species, rhizodeposits, electrode materials, wastewater treatment, and future perspectives, is presented. This system is a promising technology, not only for the production of bioenergy but also to maintain a clean environment, since during its operation, no toxic byproducts were formed. The constructed wetlands (CWs) coupled with microbial fuel cell (MFC) or called plant‐MFC have aroused a great interest to scientific community for bioenergy production and wastewater treatment. The CW‐MFC is defined as a bioelectrochemical device that converts solar energy into bioelectricity, with the help of root system of a plant. In this review, an overview is given of most recent advances for bioenergy production and wastewater treatment using CW‐MFC, including issues such as working principle and basic construction of CW‐MFC, CW‐MFC architecture, material separators, electrodes, catalysts, plants used in CW‐MFC, and pollutant removals by CW‐MFC.