Using different configurations of L. hexandra-planted constructed wetland-microbial fuel cells to remove Cr (Ⅵ) and p-chlorophenol and generate electricity.

Abstract

P-chlorophenol (4-CP) and hexavalent chromium (Cr (VI)) are predominant contaminants in industrial effluents, eliciting substantial environmental and human health concerns. As a strong oxidant, Cr (Ⅵ) has the potential to facilitate the removal of 4-CP. However, the specific removal effect remains unclear. In this experiment, we designed three different reactors based on constructed wetland-microbial fuel cell (CW-MFC) technology and planted with Leersia hexandra Swartz in a stacked configuration, multistage configuration, and modular configuration. The co-pollutant removal was investigated by analysing wastewater purification, electrochemical performance, and growth of L. hexandra. The results showed that the modular configuration achieved the best removal rates. Furthermore, this configuration generated 254.0 mV voltage and 150.60 mW·m^-3 power density. These findings showed the promise of modular technology for detoxifying wastewater containing complex mixtures while simultaneously generating electric power. Further research in this study could promote wastewater treatment and make substantial progress towards sustainable energy production.