【作者】 于萍；

【导师】 刘汝海；

【作者基本信息】 中国海洋大学 ， 环境科学， 2011， 硕士

【摘要】 锦州湾是一个三面靠陆、一面临水的半封闭海域,锦州湾沿岸分布的大型冶炼企业和化工厂等,不断向海湾大量排放含重金属污染物的废水,锦州湾已成为我国海域重金属污染最严重的海域之一。重金属由于高毒性、持久性和生物放大性等特点尤其被人们关注。本研究在2009年8月自锦州湾海域及其邻近的葫芦岛南岸海域采集了海水和沉积物样品,分析测定海水中溶解态和颗粒态Pb、Cd、Zn、Cu、As、Hg等6种重金属和沉积物中Cu、Pb、Zn、Cr、As、Hg、MeHg等重金属的含量,以研究重金属的污染和分布特征、影响要素,最后综合评价锦州湾海域重金属的污染水平。研究结果表明,锦州湾海水中重金属浓度远高于天然海水背景值,污染相对较重。Cu、Pb、Zn、Cd及As的分布规律相似,在高潮时均表现为低浓度的舌状分布,并把污染严重的海水顶托到湾底,具有同源性。海水中溶解态与颗粒态重金属相关性不明显,溶解态的Cu、Zn、Cd、As含量均高于悬浮颗粒物,Hg在两相中的含量相差不大,Pb在海水中的含量低于悬浮颗粒物中的含量。锦州湾表层沉积物中Cu、Pb、Zn、As、Hg和MeH的含量分布表现为湾的西南和西北部最高,向湾口处浓度逐渐降低,表现出受陆源污染的影响。海域表层沉积物中的Cr以自然来源为主,受到人为影响的因素较少。与国内外其它海湾比较表明锦州湾也处于较高的污染水平。通过富集系数计算结果也表明锦州湾重金属污染较重,尤其以汞和甲基汞的污染最严重。葫芦岛南部海域也受到一定的重金属污染,锦州湾的重金属污染对葫芦岛南岸海域的影响有限。分别以地累积指数法、Hakanson潜在生态危害法和基于三角模糊数的潜在生态风险评价法评价锦州湾海域的重金属污染状况。污染评价结果表明:锦州湾海域存在极高的潜在生态风险,其中以汞的污染程度最重。以基于三角模糊数的潜在生态风险评价的结果较好。更多还原

【Abstract】 Jinzhou Bay is a semi-enclosed sea facing ocean, and the dilution rate of pollutants is far less than the admission rate characteristics since its hydrological conditions of the geochemical characteristics. Several large enterprises distribute around Jinzhou Bay coastal,which includes Huludao Zinc smelting plants,a historical pollution source,and they pour large quantities of wastewater containing heavy metals continuously to the gulf. Heavy metals are particular concerned for their highly toxics, persistence, bio-magnification and other characteristics.In August 2009, 20 surface water samples, 20 surface sediment samples collected from Jinzhou Bay and 35 sediment samples in south of Huludao were determined with FAA, AFS, CVAFS,etc.. The water samples were filtered with 0.45μm cellulose acetate membrane and the sespended particulate samples were collected at the same time. Heavy metals dissolved in seawater, absorbed in particulate and sediments were measured and the extent, characteristics, influence factors and the sources of heavy metals were analysed. Finally,comprehensive assessment on pollution in Jinzhou Bay was taken.The results show that concentration of heavy metals in seawater of Jinzhou Bay is much higher than the background value. The distribution of Cd and Cu, Zn and As are similar, liqule performance in a low concentration level appeared, which suggest a same source of Cu, Pb, Zn, Cd and As, while some other elements impact them respectively. Heavy metals dissolved in seawater and particulate heavy metals act with no obvious correlation: dissolved Cu, Zn, Cd, As are higher than those suspended particles, but Hg content is almost the same in the two phases, while Pb content is lower in seawater than in the suspension.The concentrations of Cu, Pb, Zn, As, Hg and MeHg are highest in southwest and northwest of Jinzhou Bay surface sediments, and decrease towards to the mouth of the gulf, showing the impact of land-based pollution. Main factor of Cr in surface sediments is natural sources, what is less influnced by human impact. Compared with other gulf inboard and abroad, heavy metal content in Jinzhou Bay is on a higher pollution level. The results of EF also show serious heavy metal pollution in Jinzhou Bay, especially mercury and methylmercury polluted most seriously. Huludao southern area is also subjected to certain heavy metals, while it is limited impacted by Jinzhou Bay heavy metal pollution.We use geo-accumulation index method, potential ecological risk assessment method and Hakanson evaluation based on triangular fuzzy numbers to evaluate the heavy metal pollution situation of Jinzhou Bay respectively. The results show that Jinzhou Bay exist high potential ecological risk, of which the primary pollution is mercury. And the Hakanson evaluation based on triangular fuzzy numbers is better among the 3 metheds above.更多还原