DDE in sediments of the Palos Verdes Shelf, California:: In situ transformation rates and geochemical fate
DDE in sediments of the Palos Verdes Shelf, California:: In situ transformation rates and geochemical fate
复制标题
DOI：
10.1021/es7029619
复制
发表时间：
2008-09-01
影响因子：
11.4
通讯作者：
Pontolillo, James
中科院分区：
文献类型：
--
作者：
Eganhouse, Robert P.;Pontolillo, James
从1947年到1971年，世界上最大的滴滴涕生产商将生产过程中产生的废物排入洛杉矶县的下水道。大约有870- 1 450吨滴滴涕被释放到加利福尼亚州帕洛斯弗迪斯附近的海洋中，其中一部分（约100吨）存在于大陆架和陆坡的沉积物中。沉积物中含量最丰富的DDT化合物p，p '-DDE通过还原脱氯而降解，但其转化速率和控制因素尚不清楚。为了估计原位转化率和预测p，p '-DDE的长期归宿，1992年和2003年从帕洛斯弗迪斯大陆架的一个地点收集了盒式岩芯，并分析了8种DDT化合物和84种多氯联苯（PCB）同系物。多氯联苯没有显示出脱氯的迹象，1992年至2003年期间，库存没有变化。相比之下，p，p '-DDE的库存减少了43%，而p，p'-DDMU，推定的还原脱氯产物，增加了34%。研究中心p，p '-DDE的一级转化率为0.051 +/- 0.006年（-1）。多步反应模型表明，p，p '-DDE和p，p'-DDMU的库存将继续下降，而p，p '-DDNU的库存将在2014年左右达到最大值。
From 1947 to 1971 the world's largest manufacturer of DDT discharged process wastes into the sewers of Los Angeles County. Roughly 870-1450 t of DDT were released to the ocean off Palos Verdes, CA, a portion of which (similar to 100 t) resides in sediments on the continental shelf and slope. The most abundant DDT compound in the sediments, p,p'-DDE, is degrading by reductive dechlorination, but the rate of transformation and factors controlling it are not well understood. In order to estimate in situ transformation rates and predict the long-term fate of p,p'-DDE, box cores were collected in 1992 and 2003 from a single location on the Palos Verdes Shelf and analyzed for 8 DDT compounds and 84 polychlorinated biphenyl (PCB) congeners. The PCBs show no evidence of dechlorination, and inventories did not change between 1992 and 2003. By contrast, the inventory of p,p'-DDE decreased by 43%, whereas that of p,p'-DDMU, the putative reductive dechlorination product, increased by 34%. The first-order transformation rate for p,p'-DDE at the study site is 0.051 +/- 0.006 yr(-1). A multistep reaction model suggests that inventories of p,p'-DDE and p,p'-DDMU will continue to decline, whereas that of p,p'-DDNU will reach a maximum around 2014.