Abstract:

Iron containing minerals are earth-abundant, low cost, and able to tragger H₂O₂ and persulfate (PS). Biotite contains Fe²⁺ and has reducing properties, and there are limited studies on its activation of PS to remove pollutants. In this study powdered biotite (PB) was used to activate PS for degradation of a reactive azo dye, reactive green 19 (RG19). Results showed that PB was able to efficiently activate PS to produce OH· and SO₄^-·, which were responsible for the degradation of RG19. Approximately 95% of 5.0×10^-5 mol/L RG19 was decolorized in 15 min and azo bonds were completely broken down under the conditions of 5.0×10^-3 mol/L PS,1.0 g/L PB, initial pH 6.0, and 55 ℃. Decolorization process followed a pseudo-second-order (PSO) kinetics. The American dye manufacturers institute (ADMI) color scale and total organic carbon removal were both taken in consideration and the oxidative degradation efficiency at 98.2% and 71.2%, respectively. The high activation energy of 34.96 kJ/mol indicated that the reaction was significantly affected by temperature. PB can be used as an efficient activator for PS to degrade dye wastewater.

Key words: reactive green 19')">

reactive green 19, powdered biotite, persulfate')"> persulfate, degradation')">oxidation degradation, mechanism')">activation mechanism, degradation efficiency