东平湖表层沉积物中多氯联苯的污染特征

[目的]查明东平湖表层沉积物多氯联苯(PCBs)的污染特征,为东平湖沉积物的污染控制及风险评价提供科学依据。[方法]于2015年7月对东平湖16个不同点位的表层沉积物进行采样,使用GC-ECD检测了PCBs(PCB28,PCB52,PCB101,PCB118,PCB153,PCB138,PCB180)的含量,对东平湖PCBs的空间分布进行分析。运用EPA法对东平湖表层沉积物中多氯联苯进行生态风险评价。[结果]东平湖表层沉积PCBs总的含量范围为nd～605.9ng/kg,均值为126ng/kg,标准差为153。在空间分布上,湖区中部(184.5ng/kg)入湖口(149.9ng/kg)湖区西南部(101.4ng/kg)湖区北部(46.7ng/kg)。研究区PCBs同系物组成以七氯联苯为主,占总量的66.72%。与其他地区的沉积物相比较,东平湖表层沉积物中PCBs处于较低水平,风险评价表明该研究区域生物毒性效应概率远远小于10%。[结论]由于水文因素的影响,东平湖表层沉积物中多氯联苯(PCBs)呈现出由大汶河入湖口向西北方向递减的空间分布趋势;东平湖表层沉积物中的多氯联苯属于轻微污染水平,未对水体环境安全造成严重影响,沉积物中PCBs的浓度水平对大多数底栖生物无毒性影响。

Pollution Characteristics of Polychlorinated Biphenyls in Surface Sediments of Dongping Lake

[Objective] The characteristics of polychlorinated biphenyls(PCBs) pollution of surface sediments in Dongping Lake were studied in order to provide the scientific basis for pollution control and risk assessment.[Methods] PCB28,PCB52,PCB101,PCB118,PCB153,PCB138 and PCB180 in 16 different surface sediments samples were monitored in Dongping Lake in July 2015. GC-ECD was used to determine the concents of PCBs. Ecological risk assessment of PCBs in surface sediments of Dongping Lake was conducted by EPA method.[Results] The total content of PCBs was in the range of nd~605.9 ng/kg, the mean value was 126 ng/kg, and standard deviation was 153. In terms of spatial distribution, its order was:the central of the lake area(184.5 ng/kg) > entrance of lake area(149.9 ng/kg) > the southwest of the lake area(101.4 ng/kg) > the northern of the lake area(46.7 ng/kg). PCBs homologues were mainly composed of PCB7(66.72%) in the study area. Compared with other xregions sediments, PCBs in surface sediments of Dongping Lake were at a lower level. The ecological risk assessment of polychlorinated biphenyls(PCBs) in surface sediments of Dongping Lake using Regulations the United States Environmental Protection Agency(EPA), the probability of biological toxicity was much less than 10%.[Conclusion] Due to influence of hydrological factors, there was a decreasing trend of spatial distribution from the entrance of the Dawen River to the northwest direction of the PCBs in the surface sediments of Dongping Lake. The concentration of PCBs in sediments has no serious effect on the environmental safety of water, and it has no toxic effect on most benthic organism.