Membrane photo-bioreactor coupled with heterogeneous Fenton fluidized bed for high salinity wastewater treatment: Pollutant removal, photosynthetic bacteria harvest and membrane anti-fouling analysis

In this study, efficient photosynthetic bacteria (PSB)-GO/PVDF membrane photo-bioreactor (MPBR) combined with heterogeneous Fenton fluidized bed was built and successfully applied for treatment of actual refractory seafood-processing wastewater with extremely high salinity. As effective pre-treatment, heterogeneous Fenton was designed for removing non-biodegradable organics and reducing iron-sludge discharge. In MPBR, GO/PVDF membrane fabricated by chemical grafting GO nanosheets was first used for salt-tolerated PSB harvest. Compared with original PVDF membrane, GO/PVDF membrane exhibited enhanced hydrophilicity, better permeability (4.4 times) and attractive flux recover rate (94%), which was attributed to remarkable reduction in hydrophobic proteins amount of extracellular polymeric substances (EPS). Importantly, COD and NH3-N removal efficiency of MPBR with GO/PVDF membrane were kept about 95 and 98%, respectively, and average biomass productivity reached as high as 105 mg/L·d. This study provides a promising and economical way to build efficient MBR combined with new materials for high salinity hazardous wastewater treatment.