Dual-functional MgFe₂O₄-PVDF membrane enabling concurrent oil/water separation and catalytic dye degradation

Dyes and oil substances are two common pollutants in wastewater, and it is highly expected to remove them simultaneously. In this study, MgFe 2 O 4 was synthesized by co-precipitation and then loaded onto polyvinylidene fluoride (PVDF) membrane to fabricate a MgFe 2 O 4 -PVDF composite membrane, which was successfully employed for concurrent dye degradation through peroxymonosulfate activation and separation of oil-in-water emulsions through one-step single-pass filtration. Under optimum conditions, both Rhodamine B (RhB) and hexane could be efficiently removed by 99.21 % and 99.89 % respectively. The effects of pH, inorganic ions and humic acid were studied, and the system showed wide applicability and good reusability. The reaction mechanism for RhB degradation was proposed based on quenching tests, open circuit potential test, galvanic oxidation process and X-ray photoelectron spectroscopy. The degradation pathway of RhB was proposed according to density function theory calculations for both RhB and its deprotonated counterpart deH-RhB as well as LC-MS analysis, and toxicity evaluation was also performed. The MgFe 2 O 4 -PVDF/PMS system may offer a possible solution for the efficient remediation of complex wastewaters.