Surfactant removal from wastewater using photo-cathode microbial fuel cell and laterite-based hybrid treatment system

Sodium dodecyl sulfate (SDS) is a widely used anionic surfactant, which finds its way to the receiving water body due to the incapability of conventional wastewater treatment systems to completely remove it. A hybrid treatment system consisting of upflow microbial fuel cell (MFC) with titanium dioxide (TiO₂) as a photocathode catalyst was developed for treating synthetic wastewater spiked with SDS (10.00 ± 0.46 mg L^-1). Effluent from anodic chamber of MFC was passed through raw laterite soil filter followed by the photo-cathodic chamber with TiO₂-coated cathode irradiated with the UV spectrum. This hybrid system was operated under varying hydraulic retention time (HRT) in anodic chamber of MFC. The SDS removal efficiency of more than 96% along with organic matter removal efficiency of more than 71% was obtained by this hybrid system at different HRTs. The MFC having cathode coated with TiO₂ could generate a maximum power density of 0.73 W m^-3 and 0.46 W m^-3 at the HRT of 12 h and 8 h, respectively, showing the adverse effect of increased SDS loading rate on the electrical performance of MFC. This investigation highlighted the importance of HRT in anodic chamber of MFC and offered solution for effective removal of surfactant from wastewater.