The synergistic activation of peroxymonosulfate for the degradation of Acid Scarlet GR by palygorskite/MnO2/Fe3O4 nanocomposites

A heterogeneous Fenton-like system comprising palygorskite/MnO2/Fe3O4 (PMM) as a superior, low-cost, and eco-friendly ternary catalyst for the activation of peroxymonosulfate (PMS) was investigated with regard to its ability to degrade Acid Scarlet GR in an aqueous solution. Under the optimum catalytic oxidation conditions of 1 g L-1 PMM, 0.7 g L-1 PMS, and an initial pH value of 5, 200 mg L-1 Acid Scarlet GR was completely degraded within 300 min. PMM exhibited outstanding magnetic recovery ability and reusability after nine cycles with a degradation efficiency of up to 95.4%. The PMM catalyst had a broad working pH range. Singlet oxygen O-1(2) was considered to play the principal role in the degradation of Acid Scarlet GR in the PMM/PMS system. The synergistic effect between MnO2, Fe3O4, and PG substantially accelerated the catalytic activity of PMM, and MnO2 was identified to be the primary active site. These findings indicate that PMM is a nanocatalyst that can efficiently activate PMS for the treatment of dye-containing wastewater.

Automated summary

A heterogeneous Fenton-like system using palygorskite/MnO2/Fe3O4 as a ternary catalyst was studied for the degradation of Acid Scarlet GR in water. The PMM catalyst exhibited excellent magnetic recovery ability and reusability, and could efficiently degrade Acid Scarlet GR within 300 min. Singlet oxygen O-1(2) was found to play a vital role in the degradation process. These findings suggest that PMM is a promising nanocatalyst for the treatment of dye-containing wastewater.