Energy-efficient for advanced oxidation of bio-treated landfill leachate effluent by reactive electrochemical membranes (REMs): Laboratory and pilot scale studies

This study for the first time investigated the advanced treatment of bio-treated landfill leachate effluent using a novel reactive electrochemical membrane (REM) technology at the laboratory and pilot scales. At the laboratory scale, RuO2-Ir-REM, Ti4O7-REM, and beta-PbO2-REM featured similar properties in pore size and water flux. Although RuO2-Ir-REM holds more reactive sites than the other two REMs, beta-PbO2-REM and Ti4O7-REM featured higher oxidation ability than RuO2-Ir-REM, causing their high yield of hydroxyl radical. Consequently, beta-PbO2-REM and Ti4O7-REM performed better than RuO2-Ir-REM, which removed total organic carbon and ammonia nitrogen by 70%-76% and 100%, respectively, after 45 minutes of treatment. Fluorescence spectroscopy analysis showed that humic acid-like substances were oxidized by the REM treatment. Using the beta-PbO2-REM in the lab-scale setup with the solutions circulated, we observed a greater removal of chemical oxygen demand (COD) at a higher applied current or a faster water flux. The pilot system with four large size of beta-PbO2-REM s modules in series was developed based on the lab-scale setup, which steadily treated landfill leachate in compliance with the disposal regulations of China, at an energy consumption of 3.6 kWh/m(3). Also, a single-pass REM can effectively prevent the transformation of chloride to chlorate and perchlorate. Our study showed REM technology is a powerful and promising process for the advanced treatment of landfill leachate. (c) 2020 Elsevier Ltd. All rights reserved.

Automated summary

This study investigated the advanced treatment of bio-treated landfill leachate effluent using a novel reactive electrochemical membrane (REM) technology. The results showed that REM technology is effective in removing organic pollutants and ammonia nitrogen, demonstrating its high potential for use in advanced treatment processes.