Ozonation of hexazinone in O3/H2O system
O3/H2O2氧化降解环嗪酮研究

A process of hexazinone oxidation using advanced method of O3/H2O2 was studied. Variation of pseudo-first-order reaction rate constant was investigated. The optimal reaction condition and consumption of hydrogen peroxide was determined. The reaction path in the degradation of hexazinone was discovered based on the products monitoring results by IC,HPLC/MS and GC/MS. The maximum of pseudo-first-order reaction rate constant was 0.075 min-1 at the condition of initial hexazinone concentration of 3 mg·L-1,temperature of 25 ℃,ozone dosage of 13 mg·L-1,H2O2/O3 ratio of 0.5 and pH of 8～9. The inorganic ions and trace organics matters contained in tap water accelerated the hexazinone oxidation. The consumption of H2O2 was proportional to the quantity of removed hexazinone,which was mainly due to hydroxyl free radical formation. Therefore,HCO-3 obviously inhibited the degradation of hexazinone. The de-methyl-hexazinone was detected during the oxidation process. The triazine ring was broken and end products of NO-3,H2O and CO2 were achieved in the process of hexazinone degradation by O3/H2O2.