官厅水库沉积物柱状样中有机氯农药的垂直分布特征

Vertical Distribution Characteristics of Organochlorinated Pesticides in Sedimentary Core from Guanting Reservoir

以气相色谱-电子捕获检测器(GC-ECD)内标法定量测定了官厅水库永1008横断面沉积物柱状样品中有机氯农药的含量,以便对自蓄水以来官厅水库沉积物中有机氯农药的历史沉积变化特征和可能的来源进行初步探讨。定量测定结果以HCHs,DDTs和有机氯农药总量(OCPs)计算,样品中w(HCHs),w(DDTs)和w(OCPs)分别为2 0～25 7,0 3～1 9和3 2～28 3ng g;据永1008横断面沉积图推算,官厅水库永1008横断面沉积物中有机氯农药的主要来源是上游地区的农业生产和工业排污,集中在1980—1991年。因此,在未来库区的清淤疏浚工程中,应特别注意不同层次底泥中有机氯农药的再悬浮与释放,以及清淤后底泥的防污处置。

The contents of organochlorinated pesticides in the sedimentary core samples from Yong 1008 cross section of Guanting Reservoir were quantified by GC-ECD with the internal standard material, in order to preliminarily investigate the vertical distribution and potential sources of organochlorinated pesticides in the sediments in the reservoir since its water storage. The results showed that the concentration of HCHs, DDTs and total organochlorinated pesticides in the core ranged from 2.0 to 25.7 ng/g, 0.3 to 1.9 ng/g and 3.2 to 28.3 ng/g, respectively. According to the sediment map, the organochlorinated pesticides in the sediment of Yong 1008 cross section mainly come from the agricultural production and industrial pollution in the upstream from 1980 to 1991. Therefore, in the future reservoir desilting and dredging engineering, special attention should be paid to re-release of organochlorinated pesticides from the sediments at different levels and disposal of the sediments after dredging.