饮用水处理中多环芳烃和卤代多环芳烃的变化特征及健康风险

Changes and Health Risks of Polycyclic Aromatic Hydrocarbons and Halogenated Polycyclic Aromatic Hydrocarbons in Drinking Water Treatment

饮用水安全直接关系到千家万户的身体健康。为了解饮用水中多环芳烃(PAHs)和卤代多环芳烃(HPAHs)的污染现状、来源以及健康风险,选择了以长江、太湖和三河(淮安)为水源水的3个自来水厂,采用气相色谱-质谱的测定方法,分别在丰水期和枯水期对其各工艺段出水进行了采样分析。结果表明,PAHs和HPAHs在自来水厂原水和出水中普遍存在,PAHs的质量浓度为9.74~61.00 ng/L,氯代多环芳烃(Cl-PAHs)的质量浓度为0.32~9.17 ng/L,溴代多环芳烃(Br-PAHs)的质量浓度为未检出(ND)~4.15 ng/L,且整体呈现枯水期质量浓度大于丰水期的特征。原水中PAHs主要来源于石油污染以及各种燃烧活动,HPAHs与PAHs的质量浓度呈正相关;出水中HPAHs主要来源于原水以及氯化消毒。现有的自来水处理工艺对原水中PAHs和HPAHs都有一定的去除作用,但是氯化消毒可能产生新的HPAHs污染。人体健康风险评价结果表明,3个水厂出水的终生致癌风险为10^(-9)~10^(-8),处于低致癌风险水平。

The safety of drinking water is directly related to the public health of the world.In order to understand the pollution status,sources and health risks of polycyclic aromatic hydrocarbons(PAHs)and halogenated polycyclic aromatic hydrocarbons(HPAHs)in drinking water,the water samples were collected from the whole process of three waterworks using the Yangtze River,the Taihu Lake and the Sanhe Rivers as the source water in the wet and the dry seasons,respectively,and were analyzed by gas chromatography-mass spectrometry(GC-MS).The results showed that PAHs and HPAHs were prevalent in the raw water and finished water,and the concentration ranges of PAHs,chlorinated PAHs(Cl-PAHs)and brominated PAHs(Br-PAHs)were 9.74~61.00 ng/L,0.32~9.17 ng/L and n.d.~4.15 ng/L,respectively.In brief,the concentration of both PAHs and HPAHs in the dry season was greater than that in the wet season.PAHs in the raw water mainly come from oil pollution and various combustion activities,and the concentration of HPAHs is positively correlated with PAHs,while HPAHs in the finished water mainly come from raw water and chlorination disinfection.The current drinking water treatment process can remove both PAHs and HPAHs from the raw water,but chlorination disinfection may generate new HPAHs contamination.An evaluation of human health risk for the finished water from all three plants showed low carcinogenic risk levels.