臭氧/双氧水/紫外光联用降解饮用水中溴氯乙腈的试验研究

Performance of bromochloracetonitrile degradation by O_3/H_2O_2/UV process in drinking water

为减少饮用水氯化消毒过程中产生的含氮消毒副产物溴氯乙腈(BCAN),降低其潜在的致癌风险,分别采用臭氧(O3)、双氧水(H2O2)和紫外光(UV)及其联合工艺,考察了不同试验条件下BCAN的降解效果及影响因素,并探讨了其降解机制和动力学规律。结果表明,O3、H2O2和UV工艺对BCAN降解效果都不理想,UV/H2O2和UV/H2O2/O3联合工艺可以较有效地降解水中的BCAN。在BCAN初始质量浓度为20μg/L、紫外光强为31μW/cm2、H2O2质量浓度为40 mg/L、O3质量浓度为7.9mg/L条件下,反应进行120min后,UV/H2O2联合工艺与UV/H2O2/O3联合工艺对BCAN的降解率分别为77.50%、94.05%。UV/H2O2/O3联合工艺对BCAN的降解效果比UV/H2O2联合工艺更好,UV/H2O2和UV/H2O2/O3联合工艺降解BCAN均符合一级反应动力学规律。

In order to reduce the carcinogenic risk of nitrogenous disinfection by-products in drinking water produced by chorination process, degradation of bromochloracetonitrile（BCAN） by individual O3, H2O2, UV and their combined process was performed. The mechanisms and kinetics were also discussed. Results indicated that the degradation efficiencies by individual process O3, H2O2 or WV were not as good as combined process UV/H2O2 or UV/ H2 O2/O3. Under the conditions of the initial mass concentration of BCAN 20μg/L,UV light intensity 31 μW/cm2 , mass concentration of H2O2 40 mg/L, O3 7.9 mg/L and the reaction time 120 min,the degradation efficiencies by UV/H2O2 and UV/H2O2/O3 could be up to 77.50% and 94.05%, respectively. The latter process gained higher efficiency. The BCAN degradation plocess by UV/H2O2 and UV/H2 O2/O3 fit the first-order kinetic model.