关键词: 铁磁体, 尖晶石, 复合材料, 活化, 过硫酸盐, 降解

Abstract:

The iron-cobalt bimetallic composite catalyst was prepared by solvothermal method followed by high-temperature calcination to activate peroxymonosulfate (PMS) to degrade the azo dye orange Ⅱ (OGⅡ). The composites were characterized by X-ray diffractometer, scanning electron microscope, vibrating sample magnetometer and X-ray photoelectron spectrometer. The effects of cobalt compound amount, different removal systems, catalyst dosage, PMS dosage, pollutant concentration, pH and coexisting anions on the degradation effect of OGⅡ were investigated, and the reuse effect of iron-cobalt composite catalyst was explored. The experimental results show that the iron-cobalt composite catalyst can effectively activate PMS to degrade OGⅡ. When n(Co₃O₄)∶ n(Fe₂O₃)=0.1, the dosage of catalyst is 1.0 g/L, the dosage of PMS is 0.4 mmol/L, the concentration of OGⅡ is 30 mg/L and pH of solution is 6.2, after 60 min of reaction, the degradation rate of OGⅡ reached 95.81%, the degradation process conformed to the pseudo-first-order kinetic model, and the maximum reaction rate constant was 0.0491 min^-1. The composite catalyst still had a degradation rate of 68.85% to OGⅡ after 4 cycles. ·SO{}_{\mathrm{4}}^{-}, ·OH and ¹O₂ are reactive oxygen species produced in the reaction system, and ¹O₂ plays a major role in the degradation of OGⅡ.

Key words: ferromagnet, spinel, composites, activation, persulfate, degradation