A promising bioelectrochemical reactor integrating membrane distillation and microbial fuel cell for dual advantages of power generation and water recovery

Abstract

In the present study, water recovery from wastewater was accomplished simultaneously with the electrical energy production from biofuel as a source of organic matter, by the novel integration of distillation membrane and microbial fuel cell to create a system called the membrane distillation microbial fuel cell (MDMFC). A hydrophobic 0.45 μm membrane made of polytetrafluoroethylene (PTFE) was employed as a separator between the cathodic and anodic compartments to investigate multiple benefits of MDMFC for electricity generation, wastewater treatment and water reclamation at different temperature conditions. A high open-circuit voltage of 0.724 ± 0.07 V and a short circuit current of 64.55 ± 2.56 μA were achieved at 45 °C with an initial flux of 3.5 LMH. In the anodic chamber, Firmicutes, Proteobacteria, and Bacteroidetes were detected as dominant species at 45 °C, among which the Proteobacteria and Firmicutes were the most abundant sequences when an artificial substrate was used for feeding. The results indicate that 45 °C is the temperature that most significantly influences the electrochemical performance of MDMFC because of the dominance of bacterial community. Moreover, the power density increased by 99.9% when the temperature increased from 35 °C (0.99 μW m⁻³) to 45 °C (1552 μW m⁻³) and decreased by 97% when the temperature was further increased to 55 °C (43.91 μW m⁻³). Consequently, this study confirms that MD and MFC can be combined for the sustainable development of a water-energy nexus.