Integration of Microalgae-Microbial Fuel Cell with Microbial Electrolysis Cell for Wastewater Treatment and Energy Production

: The microalgae-microbial fuel cell (mMFC) enables us to perform secondary and tertiary treatment of domestic wastewater while simultaneously producing green electricity. In this work, the treatment of wastewater and producing electricity using a dual-chambered mMFC were demonstrated. Furthermore, the electricity produced by the mMFC was utilized to drive microbial electrolysis cell (MEC) for hydrogen synthesis. Primary domestic wastewater was treated in the anodic compartment of mMFC. Chemical oxygen demand (COD) removal of 67.2 and 54% was achieved in the anodic compartment of batch and continuous mode, respectively. Wetland-treated water was filled in the cathodic compartment, and Scenedesmus sp. was used as a catholyte. The overall voltage of 1.85 V was used to run a 1-L MEC. Industrial wastewater was treated with a COD removal of 73% in the MEC and biohydrogen was produced at a rate of 9.8 ± 0.2 mL L − 1 d − 1 .