饮用水中有机氯化物高级氧化工艺去除特点及机理分析

Removal characters and mechanism of organic chloride in drinking water by advanced oxidation processes

采用O3,UV,UV/空气和UV/O3工艺对三氯甲烷和氯苯2种重要氯化物的去除效果进行了比较,并就UV/O3工艺对2种有机物去除机理展开分析.试验90 min时,UV(253.7 nm)工艺氯苯分解产物氯离子浓度为2.03 mg/L,UV(253.7 nm)/O3工艺为1.80 mg/L,150 min时二者分别为2.28和2.48 mg/L;不同初始浓度下,UV/O3工艺在2 h内对三氯甲烷的去除率均高于60%;2种试验条件下,UV/O3工艺对三氯甲烷去除率分别为55.6%和56.1%,UV/空气工艺则分别达到了48.9%和53.8%;UV/空气工艺静态试验中,随着三氯甲烷的去除,水中溶解氧浓度从初始的7.25 mg/L降低为1.28 mg/L.试验结果表明,UV/O3工艺去除有机物机理较为复杂,与目标有机物自身性质密切相关.

A comprehensive comparison of degradation of chlorobenzene and trichloromethane by means of ozone（O3）,ultraviolet radiation（UV）,aeration plus UV and the combination of ozone with UV was conducted.Further work on the mechanism of applying UV/O3 method for removing these two organics was also carried out.The concentration of Cl-as a decomposed product of chlorobenzene was determined.It is shown that after 90min,the concentration are 2.03mg/L for UV（253.7nm） and 1.80mg/L with UV（253.7nm）/O3,and after 150min are 2.28mg/L and 2.48mg/L at 150min respectively.The removal ratio registered by UV/O3 is always more than 60% within 2h at different initial concentration of trichloromethane.Under two kinds of conditions the degradation rates with UV/O3 are 55.6% and 56.1%,and 48.9% and 53.8% with UV/aeration,respectively.DO decreases from 7.25mg/L to 1.28mg/L with the disappearance of trichloromethane in static experiment.It can be concluded that the characters of target organic have significant influence on removal rate by UV/O3,and the removal mechanism is relatively complicated.