升金湖湿地保护区表层沉积物中持久性有机污染物残留特征

Characteristics of Residual Persistent Organic Pollutants in Surface Sediments of Shengjinhu Wetland Reserve

[目的]研究升金湖湿地保护区表层沉积物中多环芳烃、多氯联苯和有机氯农药残留特征。[方法]按照网格布点,采集安徽升金湖国家级自然保护区湿地表层沉积物样品37个,利用HPLC和GC-ECD测定了样品中多环芳烃、多氯联苯和有机氯农药等3种典型持久性有机污染物的含量,并对其污染水平、组成来源进行了分析。[结果]升金湖表层沉积物中多环芳烃主要是苯并(a)芘,浓度为0.19~2.43 ng/g,均值为(1.01±0.54)ng/g(n=36),来源主要是近岸污水排放和周围村民生活中对煤等燃料的利用;多氯联苯浓度为0.14~5.71 ng/g,均值为(1.10±1.14)ng/g(n=37),来源主要是周围村民在生产生活中对于含PCBs物品的使用和使用过后对其不合理的处置;有机氯农药以滴滴涕和七氯为主,其中,滴滴涕浓度为0.15~4.70 ng/g,均值为(2.09±1.35)ng/g(n=35),七氯浓度为0.14~2.21 ng/g,均值为(1.13±0.05)ng/g(n=35)。所有样品中均未检测到六六六类有机氯农药的存在,滴滴涕和七氯主要来自于早期农业输入的残留。[结论]与国内外其他的湿地湖泊表层沉积物相比,升金湖湿地的持久性有机污染物污染处于较低水平,生态风险水平较低。

[Objective]The research aimed to study the residual characteristics of polycyclic aromatic hydrocarbons(PAHs),polychlorinated biphenyls(PCBs)and organochlorine pesticides in surface sediments of Shengjinhu wetland reserve.[Method]According to the grid site,37 surface sediment samples from Shengjinhu National Nature Reserve in Anhui Province were collected,and the content of three typical persistent organics(including PAHs,PCBs and organochlorine pesticides)were determined by GC-ECD,and their pollution levels and composition sources were analyzed.[Result]The PAHs in the surface sediments of Shengjin Lake were mainly benzo(a)pyrene,with a concentration of 0.19-2.43 ng/g,with an average of(1.01±0.54)ng/g(n=36).The sources were mainly near-shore sewage discharge and the use of coal and other fuels in the lives of the surrounding villagers.The concentration of PCBs was 0.14-5.71 ng/g,and the mean value was(1.10±1.14)ng/g(n=37).The source was mainly the use of articles containing PCBs in the production and life of the surrounding villagers and unreasonable disposal after use.Organochlorine pesticides were mainly DDT and heptachlor,among which the DDT concentration was 0.15-4.70 ng/g and the mean value was(2.09±1.35)ng/g(n=35);the heptachlor concentration was 0.14 to 2.21 ng/g,the mean value was(1.13±0.05)ng/g(n=35).The presence of 666 organochlorine pesticides was not detected in all samples.DDT and heptachlor mainly came from the residue of early agricultural inputs.[Conclusion]Compared with the surface sediments of other wetlands and lakes at home and abroad,the persistent organic pollutants in Shengjin Lake wetland are at a low level and the ecological risk level is low.