长江流域苏州段水中5种挥发性卤代烃水平含量检测分析

Detection and analysis of five volatile halogenated hydrocarbons in the Suzhou Section of the Yangtze River Basin

目的 了解长江流域苏州段部分水域5种挥发性卤代烃污染物的含量及不同氯化消毒方法对其含量的影响。方法 于2019年的丰水期(8月)和枯水期(11月)分别采集长江流域苏州段部分水域的水源水及9座自来水厂经氯化消毒后的出厂水,均运用气相色谱检测法进行检测。结果 水源水和出厂水中5种挥发性卤代烃的浓度均处于较低水平;水源水经自来水厂经氯化消毒工艺处理后,产生了少量的三氯甲烷、二氯一溴甲烷及一溴二氯甲烷,导致出厂水中挥发性卤代烃类水平升高;其消毒方式影响卤代烃产生的浓度梯度为:液氯>次氯酸钠>次氯酸钠+氯胺消毒。结论 长江流域苏州段部分水域挥发性卤代烃类污染物总体水平较低,经氯化消毒处理后虽有增加,但在出厂水中仍处于较低水平,以次氯酸钠+氯胺消毒方式消毒产生的挥发性卤代烃较少,可进行深入研究。

Objective To understand the contents of five volatile halogenated hydrocarbon pollutants in some waters from the Suzhou Section of the Yangtze River Basin and the effects of different chlorination and disinfection methods on their contents.Methods In the wet season( August) and the dry season( November) of 2019,the source water of some waters in the Suzhou Section of the Yangtze River Basin and the factory water of 9 waterworks after chlorination and disinfection were collected for the detection by gas chromatography. Results The concentrations of five volatile halogenated hydrocarbons in the source water and factory water are at a low level. A small amount of chloroform,dichlorobromomethane and bromodichloromethane are produced after the source water is treated by the chlorination disinfection process in the waterworks,resulting in an increase in the level of volatile halogenated hydrocarbons in the factory water. And the concentration gradient of halogenated hydrocarbons affected by the disinfection method shows an order of liquid chlorine > sodium hypochlorite > sodium hypochlorite + chloramine disinfection. Conclusion The overall level of volatile halogenated hydrocarbon pollutants in some waters of the Suzhou Section of the Yangtze River Basin is low. Despite that the volatile halogenated hydrocarbons have increased after chlorination,they are still at a relatively low level in the factory water,whereas less volatile halogenated hydrocarbons are produced by disinfection with sodium hypochlorite + chloramine,consequently in today’s increasingly severe environmental situation,we still need to pay close attention to the change of water quality.