Electrocatalytic graphene oxide/polypyrrole ceramic membrane for singlet oxygen activation of PDS: Cephalexin degradation and fouling control in mariculture wastewater

The electrocatalytic graphene oxide/polypyrrole ceramic membrane (GO/PPy CM)-peroxydisulfate (PDS) filtration system was developed to investigate mechanism of cephalexin (CLX) degradation and membrane fouling control for the complex actual maricultural wastewater treatment. The results indicated that the conductive network formed by the GO/PPy composite material significantly promoted the non-radical electron transfer mechanism, thereby achieving a CLX degradation rate of over 96 % and a singlet oxygen (¹O₂) contribution rate reaching as high as 76 %, surpassing other carbon-based materials. Further investigation revealed that the system enabled stable CLX degradation in the presence of coexisting ions and natural organic matter (NOM). Moreover, reversible fouling and irreversible fouling were dramatically reduced by 41 % and 57 % by enhancing the interfacial free energy between NOM and the membrane from 1.35 to 19.67 mJ/m². Therefore, the system achieved a satisfying CLX removal and membrane fouling control by tailoring the ¹O₂ generation pathway. In the treatment of maricultural wastewater process, the GO/PPy CM system exhibited outstanding CLX removal (84 %) and flux enhancement (13 %), with SO₄²⁻ concentration fluctuations below 8 %. This confirmed high antibiotic efficiency and environmental friendliness was obtained due to the system's high ¹O₂ generation rate and its superior filtration structure. Hence, the GO/PPy CM system exhibited superior removal efficiency for refractory pollutants and demonstrated environmental friendliness, making it a highly promising and feasible solution for the treatment of maricultural wastewater.