三峡库区水体有机氯农药污染特征

OCPS POLLUTION IN THE THREE GORGES RESERVOIR REGION

在长江三峡库区采集了111件水体样品,并用气相色谱(GC-ECD)内标法分析其有机氯农药(OCPs)的含量,探讨了研究区水体中OCPs的残留水平、分布及来源。结果表明:水体中OCPs指标,检出率为100%。HCH四种同分异构体含量范围分别为α-HCH 0.10～6.08ng/L,β-HCH 0.48～10.20ng/L,γ-HCH 0.09～8.43ng/L,δ-HCH 0.07～10.53ng/L;DDT类化合物检出率普遍较低,含量范围是:p,p'-DDE 0.01～19.14ng/L,p,p'-DDD0.04～2.13ng/L,p,p'-DDT 0.07～1.64ng/L。两类农药中HCHs在多数采样点上都能被检测到,在总体含量上干流断面HCHs普遍高于DDTs。长江干流重点位置与库区断面含量相比,HCHs高于断面,DDTs低于断面。HCHs在水库水体干流中的分布呈跳跃式波动,且每次含量波动幅度都要比前一次高。库区干流重点位置水体以β-HCH为主,但δ-HCH普遍存在。库区重点位置水体未能检测到DDT,表明其对库区水体DDTs的贡献较小。通过比值分析得出大气输入是库区水体DDT类物质的主要来源。

This study collected 111 water samples from the Three Gorges Reservoir Region. The concentrations of OCPs in the samples were determined by GC-ECD with the internal standard method. The results showed that OCPs indicators were 100% in water. The HCHs content range were α-HCH 0.10-6.08 ng/ L,β-HCH 0.48-10. 20 ng/L,γ-HCH 0.09-8.43 ng/L,δ-HCH 0.07-10.53 ng/L. Detection rate of DDT compounds were mostly lower,the content range：p,p＇-DDE 0.01-19.14 ng/L,p,p＇-DDD 0. 04-2.13 ng/ L,p,p＇-DDT 0.07-1.64 ng/L. In the majority of sampling points,HCHs were detected. On the total content of the mainstream sections,the HCHs was higher than DDTs. Key locations and section content in the reservoir area, HCHs was higher than the cross section, DDTs was lower than the cross section. The distribution of HCHs in the main stream of water body was jump volatility,and every time the content of volatility should be higher than the one before. Reservoir mainstream key location water was main β-HCH,but δ- HCH also exist. Key location did not detected DDT, indicating that the smaller contribution to the reservoir water body. Through ratio analysis,atmospheric input is the main source in reservoir water body of DDT.