北太湖沉积岩芯中有机氯农药HCH和DDT残留垂直分布特征及沉积环境意义  

VERTICAL DISTRIBUTION CHARACTERISTICS OF HCHs AND DDTs IN TWO SEDIMENT CORES FROM NORTHERN TAIHU LAKE AND THEIR SEDIMENTARY ENVIRONMENT SIGNIFICANCE

作　　者：舒卫先[1] 李世杰[1] 

机构地区：[1]中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室

出　　处：《第四纪研究》2008年第4期683-689,共7页Quaternary Sciences

基　　金：科技部国家重大基础研究前期研究专项项目(批准号:2004CCA02900);中国科学院知识创新工程重大项目(批准号:KZCX1-SW-12-I)联合资助

摘　　要：为了探讨有机氯农药HCH和DDT残留在湖泊沉积物中的赋存和演化过程，并利用其特有的时间标尺特征分析近现代在人类活动干扰下的湖泊沉积过程，2006年在太湖的竺山湾、梅梁湾利用重力采样器分别采集湖泊沉积岩芯ZS和ML，按1cm间隔分样。测定了两孔岩芯20cm深度以上的HCHs（六六六类）和DDTs（滴滴涕类）残留量，结合测年资料分析了两孔岩芯中近50年来HCHs和DDTs垂直分布特征及沉积环境意义。研究结果表明，竺山湾岩芯ZS中HCHs和DDTs的残留量分别为0．22～9．70n异／g和0．32～12．34n异／g；梅梁湾岩芯ML中HCHs和DDTs的残留量分别为0．18～11．02ng／g和0．52～13．44ng／g。尽管两孔岩芯中HCHs和DDTs的残留量不同，但指示的沉积时间一致：在20世纪50年代中期以后岩芯中HCHs和DDTs残留量均明显增加，在20世纪70年代末出现峰值，这与太湖流域有机氯农药HCH和DDT使用的历史相一致，岩芯ZS中HCHs和DDTs残留量以及岩芯ML中HCHs残留量在80年代初以后逐渐降低，这与有机氯农药HCH和DDT在1983年禁止使用的时间相对应。但在岩芯ML中20世纪90年代以后DDTs残留量又明显增加，显示有新的输入源，可能与90年代以来无锡、常州快速发展的“小化工、小农药”排污进入梅梁湾有关。研究结果同时还表明太湖沉积物中的HCHs和DDTs残留量在沉积岩芯上的变化序列可以作为指示太湖沉积过程的时间标尺，对太湖沉积环境变化的研究具有重要意义。The Taihu Lake, the third largest freshwater lake in China, is seriously eutrophic. To explore the impact of human activities on lake environment in Taihu Basin,two cores,marked ZS and ML, were collected using a gravity corer in 2006 from the Zhushan Bay and the Meiliang Bay in Northern Taihu Lake. They were sampled at intervals of 1.0cm. The concentrations of HCHs and DDTs in the upper 20cm sediments of two cores were determined by gas chronmatography with electron capture detection （GC-ECD）. Based on accurate dating of 210Pb, the vertical distribution characteristics of HCHs and DDTs in the sediment cores and their sedimentary environment significance were discussed. The concentrations of HCHs and DDTs in ZS core ranged 0. 22 -9.70ng/g and 0.32 ~ 12.34 ng/g, respectively; they were 0. 18 - 11.02ng/g and 0.52 ~ 13.44ng/g, respectively in ML core. The concentrations of HCHs and DDTs increased significantly after the mid-1950s and reached the peak value in the late 1970s which is consistent with the usage history of organochlorinated pesticide DDT and HCH in Taihu Basin. The concentrations of HCHs and DDTs in ZS core and that of HCHs in ML core decreased gradually after the early 1980s,which corresponds to the official ban of pesticide DDT and HCH in 1983. However the concentration of DDTs still increased significantly in ML core after the 1990s,which indicates the existence of new input sources due to the rapid development of small chemical industries in Wuxi and Changzhou during the same period. The results show that the vertical variety of concentrations of HCHs and DDTs can be used as the time scale of sedimentary process and it has an important significance to study the sedimentary environment change in Taihu Lake.

关 键 词：北太湖 DDTS HCHS 沉积岩芯 沉积环境意义 

分 类 号：X524[环境科学与工程—环境工程]