Abstract:A typical mineral processing agent benzohydroxamic acid (BHA) was degraded by thermal activated potassium persulfate (PS). The effects of temperature, PS concentration, BHA concentration, pH and anions on the degradation effect of BHA were investigated. The reaction mechanism of the degradation system was investigated by the quenching experiments of ethanol and tert-Butyl Alcohol. The degradation mechanism was determined by analyzing the degradation products and the active species of the system, and the toxicity of the degradation system was verified by the germination experiment of mung bean. The results showed that the higher the concentration of PS and the higher the temperature, the better the degradation effect. Under the condition of 70 °C and 1.5 mmol/L of PS, the removal rate of 20 mg/L BHA reached 91.34% in 120min. The degradation of BHA was promoted by both strong acidic and alkaline conditions. HCO3-^{, SiO}32-^{, and Cu2+} were beneficial to the removal of BHA. SO4.^- played an important role in the degradation of BHA during the thermally-activated PS system. The main products of BHA were benzoic acid and hydroxylamine, and the adding of Cu²⁺ promoted the transformation of hydroxylamine to gaseous nitrogen. The mung bean germination test showed that the toxicity of the beneficiation wastewater after treatment was significantly lower than that of the original solution.

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