In-situ coating PVDF membrane by polystyrene sulfonic acid doped polyaniline to improve its anti-fouling performance and acid resistance

Membrane separation is a promoting technology in acid containing wastewater treatment. However, the poor acid resistance was still a challenge that hindered its extensive utilization. In this study, the polystyrene sulfonic acid (PSSA) doped polyaniline (PANI) was in-situ coated onto polyvinylidene fluoride (PVDF) to achieve an acid resistant composite membrane. The successful synthesis of the composite membrane was verified using ATR-FTIR, XPS and SEM characterizations. The membranes that were prepared showed outstanding anti-fouling properties, demonstrated by a flux recovery rate of over 95.0 %. The membrane acid resistance was assessed through static immersion in a 10.0 wt% H2SO4 solution for 120 days, as well as dynamic filtration with 1.0 wt% H2SO4 for 15 days. The structure and antifouling capabilities comparison indicated that the acid resistance of the composite membrane was obviously superior to the original PVDF membrane. The corresponding mechanism was also proposed to demonstrate the acid resistance of the composite membrane. Due to its exceptional anti-fouling performance and acid resistance, as well as the simple one-pot preparation process, the coated composite membrane presented enormous potential for using in acid wastewater treatment.