Mechanism and toxicity assessment of Cu0/Fe3O4 activated persulfate based on the acceleration cycle of Fe3+/Fe2+for the degradation of methyl orange

Accelerating the circulation of Fe3+/Fe2+ 3+ /Fe 2+ contributed to the production of SO4 4 during persulfate activation in the treatment of refractory wastewater. In this study, magnetic Cu0/Fe3O4 0 /Fe 3 O 4 was prepared to enhance the Fe3+/Fe2+ 3+ /Fe 2+ circulation and the separation of Cu0/Fe3O4. 0 /Fe 3 O 4 . The composition, structure, catalytic activity and toxicity of Cu0/ 0 / Fe3O4 3 O 4 were investigated. The degradation mechanisms of MO were investigated, as well as the toxicity of MO and the breakdown products were evaluated. The results showed that Cu0/Fe3O4(1:3) 0 /Fe 3 O 4 (1:3) was more efficient for PS activation as compared with single Cu0 0 or single Fe3O4. 3 O 4 . Removal efficiency of MO was up to 94.2% and center dot OH and 1 O 2 played the dominant role. Cu0 0 and in-situ generated Cu+ + accelerated the circulation of Fe3+/Fe2+ 3+ /Fe 2+ and electron transfer efficiency from Cu0/Fe3O4(1:3) 0 /Fe 3 O 4 (1:3) to PS. MO molecule was effectively decomposed through hydroxylation and the cleavage of N-C - C and N--N - - N bonds. The leachate toxicity of Cu0/Fe3O4(1:3) 0 /Fe 3 O 4 (1:3) was low, and the toxicity of intermediate products produced during the reaction was significantly less than MO. In conclusion, this study proposed a feasible pathway for rapid cycle of Fe3+/Fe2+ 3+ /Fe 2+ on the Fe3O4 3 O 4 surface and separation of Cu0 0 by using Cu0/Fe3O4 0 /Fe 3 O 4 as a promising activator for PS, effectively improving the degradation efficiency of MO.