Although the activation method of permonosulfate has been gradually developed, its practical application is severely restricted by the high cost and difficult recovery of the catalyst, thereby resulting in secondary pollution. In this study, the application potential of self-decolorization of dyes and degradation of other pollutants through persulfate(PS) activation was examined by building a self-decolorization system. The results showed that the dyes could activate PS under visible light irradiation, which could realize not only the self-decolorization of dyes, but also the degradation of other pollutants. The degradation rates of rhodamine B and bisphenol A could reach 80% and 90%, respectively. This process included both free radical reaction pathways and nonradical reaction pathways. The active oxidants produced in the system included superoxide radicals, sulfate radicals, hydroxyl radicals, and singlet oxygen. The self-decolorization efficiency of dyes was related to the type of dyes, initial concentration of the dyes, dosage of PS, and initial pH of the solution. Meanwhile, the initial concentrations of the dyes and other pollutants had a great influence on the degradation of other pollutants. This study provides a new idea for economic and environmental protection in the PS activation method, and has broad application prospects in the treatment of printing and dyeing wastewater.
Keywords: advanced wastewater treatment; dye; nonradical reaction; persulfate(PS); photocatalysis; radical reaction.