天津市环境空气中卤代烃污染特征

Pollution Characterization of Halohydrocarbon in Ambient Air of Tianjin

为研究天津市区环境空气中卤代烃的污染特征,对夏季天津市区26个采样点进行了卤代烃的监测,并且选择蓟县九山顶风景区作为对照点。采用Agilent7890A/5975C气相色谱质谱联用仪共定量检测出8种卤代烃,其中5种卤代烃的检出率大于50%,分别为二氯甲烷、氯苯、二氯二氟甲烷、三氯氟甲烷和氯甲烷。本文重点对这5种卤代烃进行了浓度水平分析,5种卤代烃的平均浓度从高到低依次为:氯甲烷(6.75μg/m3)>二氯二氟甲烷(5.43μg/m3)>二氯甲烷(4.09μg/m3)>三氯氟甲烷(2.95μg/m3)>氯苯(0.46μg/m3)。通过市内6区及不同功能区卤代烃的浓度比较,南开区卤代烃的浓度普遍较高,河西区卤代烃浓度普遍较低。各功能区氯甲烷和氯苯的浓度均高于对照点,商业区三氯氟甲烷的浓度明显高于其他功能区。

To study the pollution characteristics of halohydrocarbons in Tianjin urban ambient air, 26 sampling points were selected to monitor the contents of the halohydrocarbon in summer with the Jixian Kowloon peak scenic area as the control point. The Agilent 7890A/5975C GS-MC spectrometer was used for the quantitative detection of 8 kinds of halohydrocarbon, with the detection rate for 5 kinds of halohydrocarbon greater than 50%, that is, dichloromethane, chlorobenzene, dichlorodifluoromethane, trichlorofluoromethane and chloromethane. This paper focuses on these five kinds of halogenated hydrocarbons and it is shown that the average concentrations of the five halohydrocarbons from high to low are： 6.75μg/m3（chlorometham）, 5.43μg/m3（dichlorodifluomethane）, 4.09μg/m3 （dichloromethane）, 2.95μg/m3（trichlorofluoromethane） and 0.46μg/m3（chlorobenzene）. Among the six city areas and different function areas, the halohydrocarbon concentrations are generally high in the Nankai District and lower in the Hexi District. The methyl chloride and benzene concentrations in the functional areas are higher than in the control point, and the trichlorofluoromethanes concentration in the business area is significantly higher than in other functional areas.