太原市小店污灌区地下水中多环芳烃与有机氯农药污染特征及分布规律

Pollution Characteristics and Distribution of Polycyclic Aromatic Hydrocarbons and Organochlorine Pesticides in Groundwater at Xiaodian Sewage Irrigation Area,Taiyuan City

污水灌溉在华北水资源匮乏地区得到广泛应用,但却可能会将有机污染物引入地下水.为查明有机污染物在污灌区地下水中的污染现状,本文选取山西省小店污灌区为研究区,采集了16个地下水样品(浅层水样品13个,深层水样品3个),利用气相色谱-质谱联用仪(GC-MS)分析了多环芳烃(PAHs)的含量、利用气相色谱-电子捕获器(GC-ECD)分析了有机氯农药(OCPs)的含量.结果表明,研究区地下水中PAHs的浓度范围为13.98~505.89 ng·L-1,平均浓度为115.67 ng·L-1,以2~3环的低环芳烃为主,萘和菲的检出率最高;OCPs的浓度范围为13.91~103.23 ng·L-1,平均浓度为40.99 ng·L-1,检出率最高的为α-六六六、δ-六六六、2,4-滴滴滴、艾氏剂、硫丹硫酸酯、六氯苯.总体来看,深层水的有机污染物浓度明显低于浅层水;各水渠附近地下水中有机污染物浓度顺序为:东干渠<北张退水渠<太榆退水渠,显示地下水水质受到污水灌溉的影响.

Sewage irrigation has been widely used in areas of water shortage in northern China,and it may introduce organic contaminants into groundwater. To characterize the organic contaminants in groundwater in sewage irrigation area,the Xiaodian sewage irrigation area in Shanxi Province was chosen as the case study area. A total of 16 groundwater samples( 13 from shallow aquifer,3from deep aquifer) were collected. Polycyclic aromatic hydrocarbons( PAHs) were determined by gas chromatography-mass spectrometry( GC-MS) and organochlorine pesticides( OCPs) were analyzed by gas chromatography-electron capture detection( GCECD). The results showed that the concentrations of PAHs ranged from 13. 98 to 505. 89 ng·L-1with an average concentration of115. 67 ng·L-1. The 2 and 3 ring-PAHs were the main components,while naphthalene and phenanthrene were most frequently detected. The concentrations of OCPs were in the range of 13. 91-103. 23 ng·L-1with an average concentration of 40. 99 ng·L-1,while α-HCH,δ-HCH,o,p’-DDD,Aldrin,Endosulfan-sulfate and HCB were most frequently detected. Overall,shallow aquifers appeared more contaminated with these pollutants than deep aquifers. In the area,the order of the organic contaminants concentration in groundwater was: East Main Channel < Beizhang Drainage < Taiyu Drainage,which indicated the quality of groundwater was influenced by the sewage irrigation.