New sustainable approach for the production of Fe₃O₄/Graphene oxide-activated persulfate system for dye removal in real wastewater

Persulfate (PS)-activated, iron-based heterogeneous catalysts have attracted significant attention as a potential advanced and sustainable water purification system. Herein, a novel Fe₃O₄ impregnated graphene oxide (Fe₃O₄@GO)-activated persulfate system (Fe₃O₄@GO+K₂S₂O₈) was synthesized by following a sustainable protocol and was tested on real wastewater containing dye pollutants. In the presence of the PS-activated system, the degradation efficiency of Rhodamine B (RhB) was significantly increased to a level of 95% compared with that of Fe₃O₄ (25%). The influences of different operational parameters, including solution pH, persulfate dosage, and RhB concentration, were systemically evaluated. This system maintained its catalytic activity and durability with a negligible amount of iron leached during successive recirculation experiments. The degradation intermediates were further identified through reactive oxygen species (ROS) studies, where surface-bound SO₄^- was found to be dominant radical for RhB degradation. Moreover, the degradation mechanism of RhB in the Fe₃O₄@GO+K₂S₂O₈ system was discussed. Finally, the results indicate that the persulfate-activated Fe₃O₄@GO catalyst provided an effective pathway for the degradation of dye pollutants in real wastewater treatment.