Effect of microwave activation on degradation of aniline aerofloat by persulfate

The typical beneficiation reagent aniline aerofloat was treated by the advanced oxidation technology of microwave activated persulfate in the mineral processing wastewater. The effect of different reaction conditions, microwave power, persulfate concentration, initial pH of reaction solution, metal ions Fe²⁺ and Cu²⁺, and common anions in water (Cl^-, HCO₃^-, NO₃^- and SiO₃^2-) were studied. In addition, the reaction products and degradation mechanism were analyzed. The experimental results showed that microwave activated persulfate could effectively degrade aniline aerofloat. With the increase of microwave power and the concentration of persulfate, the degradation rateof aniline aerofloat also increased. When the initial pH was 3, the degradation effect of aniline black was optimal. Low concentration metal ions of Fe²⁺ and Cu²⁺ could promote the activation of persulfate, and accelerate the degradation of aniline aerofloat. The common anions Cl^-, HCO₃^-, NO₃^- and SiO₃^2- in water all had inhibition effect on degradation. In the processed of oxidative degradation of aniline aerofloat in the reaction system, microwave thermal effect was the main reaction condition, and SO₄^-· played an important role in the reaction. After reaction for 180 min, the mineralization efficiency of aniline aerofloat reached 45.27%. Through liquid chromatography detection, it was speculated that aniline black drug was oxidized into o-diphenol after being treated by microwave activated persulfate system, and then further oxidized and degraded into other small molecular substances, carbon dioxide and water.