七种卤乙酸在紫外辐照下的光降解行为(英文)

针对典型的氯消毒副产物卤乙酸,研究选取了7种卤乙酸,包括3种氯乙酸,3种溴乙酸和1种碘乙酸,研究其在紫外辐照下的光降解行为;并针对卤乙酸的类型和卤化程度,对比和分析了不同卤乙酸的光降解规律。结果表明:7种卤乙酸都能够被紫外降解,动力学研究结果显示,氯乙酸,溴乙酸和碘乙酸的光降解行为有很大不同,其中溴乙酸满足一级动力学模型。离子色谱检测分析了7种卤乙酸光降解过程中卤素离子的释放结果发现,碳卤键在紫外照射下发生了断裂,实现了脱卤和脱毒。为水中卤乙酸的高效去除提供了一定的技术参考和理论支撑。

Photodegradation of seven Haloacetic acids by UV irradiation

Haloacetic acids(HAAs) is a typical class of chlorine disinfection by-products and widespread in the environment.HAAs is of great concern for its high toxicity and persistence,threatening the health of human and wildlife.However,the efficient and complete removal of HAAs is still a major challenge for the current technologies.Ultraviolet(UV) is a promising technology for pollution remediation,and the present study selected seven haloacetic acids,three chloroacetic acids,three bromoacetic acids,and an iodoacetic acid,to investigate their photodegradation under UV irradiation.All HAAs underwent certain photodegradation,and comparison on photodegradation of chloroacetic acids,bromoacetic acids,and iodoacetic acids were performed,and tentative interpretation was also proposed.Further kinetic study was carried out to investigate the detailed photodegradation process of HAAs during the UV irradiation,and some differences were observed among chloroacetic acids and bromoacetic acids and iodoacetic acids.Finally,released halide ions were also identified and determined to explore and quantify the dehalogenation process during photodegradation of HAAs,and indicated that cleavage of C-Cl and C-Br and C-I bonds occurred under UV irradiation,suggesting detoxification of HAAs.The present study indicates the feasibility of UV irradiation to remove and detoxify haloacetic acids in water.