新疆焉耆盆地平原区地下水有机污染特征初步分析

Preliminary analysis on the organic contamination of groundwater in the plain area of Yanqi Basin,Xinjiang

在新疆焉耆盆地平原区采集了42组地下水水样,检测有机污染物共计39项.对所有水样测试结果的统计显示,焉耆盆地平原区地下水中检出的有机污染物共有3种,分别是三氯甲烷、1,2-二氯乙烷和1,2-二氯苯,检出率分别为30.95%、2.38%和2.38%,检出的3项有机污染物含量均低于饮用水标准;不同含水层类型的有机污染物检出率为潜水(50.00%)>深层承压水(33.33%)>浅层承压水(27.27%);不同土地利用类型的有机污染物检出率为牧草地(42.86%)>耕地(34.48%)>建设用地(16.67%);有机污染物14个检出点大部分分布在包气带岩性为亚黏土(41.18%)与亚砂土(40.00%)的区域,其余分布在包气带岩性为砂砾石(20.00%)的区域;地下水中检出的有机污染物不是来自于地表水的补给;深层承压水检测出有机污染物是由于有机污染物垂向渗透污染以及地下水混合开采、止水不佳所致.

The groundwater quality is highly influenced by input of contaminants from various sources. In order to acquire the current status of groundwater quality in the Plain area of Yanqi Basin,Xinjiang,42 groundwater samples were collected according to the relating requirements and standards. The detection of organic pollutants in the study area was the first time and totally come to39 testing items. The samples were analyzed by qualified laboratories. The investigation results showed that there were 3 organic contaminants detected in groundwater. Among these compounds,detection rate of trichloromethane,1,2- dichloroethane and 1,2- dichlorobenzene were 30. 95%,2. 38% and 2. 38%,respectively. Content of the three compounds did not exceed the drinking water standards. The results showed that in the plain area of Yanqi Basin detection rate of groundwater organic pollutants of different aquifers were phreatic water（ 50. 00%）〉 deep confined water（ 33. 33%）〉 shallow confined water（ 27. 27%）. Detection rate of the groundwater organic pollutants of the different land use types were grassplot（ 42. 86%） 〉cultivated land（ 34. 48%） 〉construction land（ 16. 67%）. Most of the 14 detection points of groundwater organic pollutants distributed the unsaturated zone of the loam（ 41. 18%） and the sandy loam（ 40. 00%） regional.The others distributed the unsaturated zone of the sandy gravel（ 20. 00%） regional. The organic pollutants in groundwater were not from the surface water. Organic pollutants exist in the deep confined water because of vertical infiltration pollution of organic pollutants,mixed-layer pumping and poor interval plugging.