Energy recovery and hygienic water production from wastewater using an innovative integrated microbial fuel cell–membrane separation process

Abstract

Abstract In this study, wastewater treatment was destined for generation of electricity and hygienic water by an innovative integrated microbial fuel cell – membrane separation process (MFC-MSP). An optimal antifouling nanofiltration membrane (blended with O-carboxymethyl chitosan bound Fe3O4 magnetic nanoparticles (CC Fe3O4 NPs)), an antifouling ultrafiltration (UF) membrane (blended with polycitrate-alumoxane nanoparticle (PC-A)) and a high efficiency proton exchange membranes were applied in MSP and MFC processes. Firstly, the performance of MFC unit under different operating conditions of reaction time (RT), mixed liquor suspended solid (MLSS) concentration and influent chemical oxygen demand (COD) concentration was investigated in terms of COD removal efficiency and power generation for synthetic dairy wastewater treatment. The experiments were modeled using response surface methodology (RSM). The results indicated that by increasing in RT and CODin concentration, the COD removal was decreased. Also, the high concentration of MLSS in anodic chamber led to high COD removal efficiency. By increasing of MLSS beyond 3000 mg/L, the maximum power generation was decreased that reveals an adverse impact of biofouling on membrane performance. After primary treatment in anodic chamber of MFC at optimum condition, the anodic chamber effluent was passed through the membranes in two modes, direct nanofiltration (NF) membrane and UF-NF membranes in series. The results indicated that the UF membrane alleviated the organic loading of NF membrane by 72% relative to the direct NF filtration. The permeation flux shows a sustain performance of the NF when is coupled with UF membrane.a.