State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), POPs Research Center, School of Environment, Tsinghua University, Beijing, 100084, China.
Environ Sci Pollut Res Int. 2014 Mar;21(6):4516-26. doi: 10.1007/s11356-013-2400-8. Epub 2013 Dec 12.
A large-scale sampling program was conducted to simultaneously collect surface water, overlying water, pore water, and sediment samples at monthly intervals between March and December 2010 from Baiyangdian Lake, North China to assess the distribution of DDTs and determine the net direction of sediment-water exchange. Total DDT concentrations ranged 2.36-22.4 ng/L, 0.72-21.9 ng/L, 2.25-33.7 ng/L, and 4.42-7.29 ng/g in surface water, overlying water, pore water, and sediments, respectively, which were at the intermediate levels compared to those of other area around the world. Seasonal variations of DDTs were featured by higher concentration in summer. This was likely associated with (a) the increase of land runoff in the summer and (b) application of dicofol and DDT-containing antifouling paints for ships in summer. Sediment-water fugacity ratios of the DDT isomers were used to predict the direction of the sediment-water exchange of these isomers. The sediment-surface water, sediment-overlying water, and sediment-pore water fugacity ratios of DDT isomers averaged 0.34, 0.44, and 0.1, which are significantly lower than the equilibrium status (1.0), suggesting that the net flux direction were from the water to sediment and the sediment acted as a sink for the DDTs. The difference of DDT concentrations between sediment and water samples was found to be an important factor affecting the diffusion of DDT from the water to sediment.
2010 年 3 月至 12 月，在中国华北地区的白洋淀进行了大规模的采样计划，每月采集一次地表水、上覆水、孔隙水和沉积物样本，以评估滴滴涕的分布情况，并确定泥沙-水交换的净方向。总滴滴涕浓度在地表水、上覆水、孔隙水和沉积物中的范围分别为 2.36-22.4ng/L、0.72-21.9ng/L、2.25-33.7ng/L 和 4.42-7.29ng/g，与世界其他地区相比处于中等水平。滴滴涕的季节性变化特征是夏季浓度较高。这可能与以下两个因素有关：(a) 夏季陆地径流量增加；(b) 夏季船舶使用了三氯杀螨醇和含滴滴涕的防污漆。滴滴涕异构体的沉积物-水逸度比用于预测这些异构体在沉积物-水交换中的方向。滴滴涕异构体的沉积物-水、沉积物-上覆水和沉积物-孔隙水逸度比平均值分别为 0.34、0.44 和 0.1，明显低于平衡状态（1.0），表明净通量方向是从水到沉积物，沉积物是滴滴涕的汇。沉积物和水样中滴滴涕浓度的差异被发现是影响滴滴涕从水扩散到沉积物的一个重要因素。
