三沙湾溪邳村滩涂养殖区沉积物质量状况及风险评价

Status and risk assessment of sediment samples on the mud-flat culture areas of Xipi Village in Sansha Bay

为了解三沙湾溪邳村滩涂养殖环境污染现状,2012年4月对该养殖区表层沉积物中有机碳、油类、硫化物、总磷、总氮、多氯联苯、滴滴涕和重金属(Cu、Zn、Pb、Cd、Cr、Hg、As)含量进行分析与评价。结果表明:该海域沉积物中总氮含量达到生源要素Ⅱ类污染水平;单因子污染指数法的主要污染因子是氮和磷,富营养化程度较高;Hakanson潜在污染因子较大的是汞和镉,风险水平总体不高,但污染程度受人为活动等外来源影响有缓慢增加的趋势;而生物效应浓度法显示,沉积物中DDTs含量大于ERL限值,构成一定生态风险,但沉积物综合生态风险(联合毒性)不大,对生物产生中低毒性,毒性概率约为30%。

To understand the quality status and risk assessment of the mud - flat culture areas on Xipi Village in Sansha Bay, investigation and analysis were done with the contents of TOC, TPH, AVS, TP, TN, PCBs, DDTs and several heavy metals （Cu, Zn, Pb, Cd, Cr, Hg, As） on sediments in April2012. The result showed that the TN contents had reached to the second standard of the potential ecological risk with bio- genic elements. The main single factor pollution factors were TN and TP which at the state of eutrophication. Thirdly, Hg and Cd were the two major Hakanson potential ecological risk factors and the total potential eco- logical risk was low while the pollution trend was increased slowly by human impact. Lastly, the bio - effect concentration criterion showed that the contents of DDT exceeded the ERL level and had some risk of biological toxicity while the comprehensive ecological risk of sediments were possessed low potential ecological risk and their ecological harm probability was 30% by mERM -Q.