UV/O_3氧化工艺处理水中六氯苯的研究

DEGRADATION OF HEXACHLORBENZENE IN WATER BY O_3 AND UV/O_3

采用UV、O3及UV/O3高级氧化法对水中六氯苯(HCB)的降解效果及机理进行了研究,并对结果进行了比较。结果表明,UV本身对HCB的去除贡献不大,HCB可被O3、UV/O3快速降解,即UV<O3<UV/O3;在pH=3,HCB=0.2mg/L,反应40min时,UV/O3对HCB的去除可达50%左右,酸性条件下有利于降解反应的进行;无论是O3单独作用还是UV/O3联合作用,HCB的降解基本上满足准一级反应动力学规律,如果体系的pH值基本保持恒定,这种规律就更为明显。根据离子色谱(IC)、GC对六氯苯降解中间产物进行了测定,探讨了O3、UV/O3降解六氯苯的途径和机理。

The effect and the mechanism ofhexacblorobenzen （HCB） degradation in water were studied and the results were compared with these by the advanced oxidation process O3 and UV/O3. The experimental results showed that UV itself did not contribute to the removal of HCB obviously and HCB could be quickly degraded by O3 and UV/O3, namely UV〈O3〈UV/O3. But in the case of 03 and UV/O3, both raising the initial pH value of the system could not raise the removal rate of HCB, the removal efficiency of 0.2mg/L HCB could reach 50% within 40 min when the initial pH value was equaled to 3 and the degradation velocity could be accelerated in the acidic solution. Whether in the cases of ozone action alone or UV/O3 combined action, the degradation of HCB satisfied basically the rule of pseudo-first order reaction kinetics; and this rule was more remarkable if a constant pH value of the system was maintained. The degradation pathway and mechanism of HCB were discussed according to the measured results of the intermediated sub- stances from the HCB degradation process by ionic chromatography（IC） and gas chromalography（GC）.