闽江口水、间隙水和沉积物中有机氯农药的含量

利用GC-ECD和GC-MSD对1999年11月闽江口水、间隙水和沉积物中的有机氯农药进行了研究.结果显示,闽江口水中有机氯农药的含量范围是0.532～1.82μg/L,间隙水中有机氯农药的含量为4.54～13.7μg/L,沉积物(于重,以下讨论到的沉积物,无特别说明都是干重表示):28.79～52.07μg/kg;与其他河口如珠江口、九龙江口相比,闽江口的污染水平居中.间隙水的污染物浓度普遍高于其上覆水的浓度,而沉积物中的浓度大于间隙水、表层水,是由于有机污染物在水体中倾向于吸附在沉积物颗粒,并且通过再悬浮从底层向上迁移.对水体中有机氯农药各组分的含量及特征进行了分析,发现有机氯农药的主成分为:β-HCH,DDE,Heptachlor(七氯),Endosulfan Ⅱ(硫丹),Methoxychlor(甲氧滴涕).DDE、β-HCH、EndosulfanⅡ分别占DDTs、HCHs和硫丹的主要部分;有机氯农药各组分间有正相关性,表明其河口有机氯农药陆源的土壤输入与相似的环境行为;对该河口的污染水平进行了初步的评价,HCHs符合国家海水水质一级标准,DDTs则超过该标准.

Contents of Organochlorine Pesticides in Water, Pore Water and Sediment in Minjiang River Estuary of China

The concentrations of 18 organochlorine pesticides in water, pore water and surface sediment from Minjiang River Estuary were analyzed by GC-ECD, and confirmed by GC-MSD. The range of organochlorine pesticides was 0.532-1.82 micrograms/L at water, 4.54-13.7 micrograms/L at pore water, and 28.79-52.07 micrograms/kg at sediment. Compared with the results of other estuaries and gulfs (Pearl River Estuary, Jiulong River Estuary and so on), it showed that the pollution of organochlorines in Minjiang was some moderate. The concentration difference in surface water, middle water, bottom water, pore water and sediment, due to the higher affinity of these hydrophobic compound for sedimentary phase than to water and a potential flux of pollutants from sediment to overlying water. The predominance of beta-HCH, DDE, Heptachlor, Endosulfan II and Methoxychlor in all water, pore water and sediment were clearly observed. On average, DDE, beta-HCH, Endosulfan II occupied the most part of total DDTs, HCHs and Endosulfans respectively, indicated the fate of these parent compounds or congeners. At the same time, it was found that the positive relationship among the individual organochlorine components (HCHs, DDTs and Endosulfans), which indicated that the similar of the source and behavior for organochlorine pesticides.