| 红枫湖钻孔沉积物中滴滴涕的沉积记录 |
| 摘要点击 2125 全文点击 1781 投稿时间：2009-07-26 修订日期：2009-09-10 |
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| 中文关键词 红枫湖 沉积柱 滴滴涕 来源 风险评价 |
| 英文关键词 Hongfeng reservoir sediment core DDTs sources risk assessment |
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| 中文摘要 |
| 采用GC/MS方法分析了红枫湖钻孔沉积物中滴滴涕的垂直分布状况，并对其来源和生态风险进行了分析和评估.红枫湖钻孔沉积物中滴滴涕的含量介于7.6～23.7ng/g之间，且从底层至表层基本上呈下降的趋势.其中，1981～1983年间有一个急剧下降的过程，随后基本上呈缓慢下降的趋势.沉积物中滴滴涕的组成以p,p′-DDTs（p,p′-DDT、p,p′-DDE和p,p′-DDD的总和）为主，p,p′-DDTs与o,p′-DDTs（o,p′-DDT、o,p′-DDE和o,p′-DDD总和）的比值在5.1～8.4之间，说明沉积物中的滴滴涕主要来源于农药滴滴涕的残留.又因为沉积物中残留的滴滴涕是以它的代谢产物为主，DDT/(DDD+DDE)的比值为0.31～0.84，所以沉积物中的滴滴涕主要源于历史的残留.此外，DDT/(DDD+DDE)和DDE/DDD比值的垂直变化特征显示，尽管我国1983年就禁止了滴滴涕在农业上的使用，但直至1990年前后，红枫湖流域内仍存在滴滴涕使用的可能.风险评价的结果显示，红枫湖表层沉积物中DDE、DDD、DDT和DDTs的含量均介于ERL和ERM值之间，可能造成潜在的生态风险，因此红枫湖沉积物中滴滴涕的污染仍值得密切关注. |
| 英文摘要 |
| In order to reconstruct the chronology of 2,2-his(4-Chlorophenyl)-1,1,1-trichloroethane (DDT) input into the Hongfeng reservoir and assess the pollution issues, the temporal distribution of DDT in sediment core from Hongfeng reservoir was measured using GC/MS method, and the possible sources and potential risk assessment also had been identified. The DDTs (sum of p,p′- and o,p′-DDT, DDE and DDD) in sediment core were ranged from 7.6 to 23.7ng/g, and roughly, ever decreased from the bottom to the surface sediment. In detail, a sharp decline of DDTs concentration in sediment was found from 1981 to 1983, followed by a tardy decrease trend to the present. The DDTs in sediment were mainly composed of p,p′-DDTs (sum of p,p′-DDT, DDE and DDD). The ratio of p,p′-DDTs to o,p′-DDTs (sum of o,p′-DDT, DDE and DDD) ranged from 5.1 to 8.4, which suggests that the DDTs in sediment were chiefly originated from the technical DDT. Meanwhile, the DDTs in sediments were dominated by the metabolites of DDT (DDD and DDE) and the ratio of DDT/(DDD+DDE) were between 0.31and 0.84, indicating the DDTs in sediment were mostly stemmed from the historical usage. Besides, the vertical profile of the ratios of DDT/(DDD+DDE) and DDE/DDD indicate that possible usage of technical DDT still occurred in the drainage area of Hongfeng reservoir around 1990, although the usage of technical DDT in agriculture has been banned in 1983. The residue levels of DDE, DDD, DDT, and DDTs in surface sediment from Hongfeng reservoir were all between ERL and ERM, suggesting potential risk could occur, and the contamination of DDT in Hongfeng reservoir deserving more concerns. |
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