Evaluation Of Heavy Metal Pollution In Surface Sediment Of Jinzhou Bay

Jinzhou Bay was one of areas suffering from serious heavy metal pollution in China. Because of the rapid development of economy, lots of industrial, agricultural and domestic wastewaters were discharged into the coastal area, and the marine ecological environment was seriously deteriorated. Sediment was a major reservoir for heavy metals, when the environment condition was changed (the increase of salinity, the changes of oxidation-reduction condition and pH descended etc.), the metals adsorbed on the particulates were released again, and the entire coastal ecosystem was seriously threatened. The present paper was based on fourteen surface sediment samples collected in Jinzhou Bay, the heavy metal contents in the samples were determined, and the heavy metal speciation analysis in the sediment samples was studied by Tessier sequential extraction procedure, meanwhile, the research on bioaccumulation of heavy metals in five sediment samples was conducted by using the Ruditapes philippinarum as the test organism. The evaluation of heavy metal pollution in the surface sediment of Jinzhou Bay was discussed in this paper.In the present paper, analytical methods for determination of heavy metals in sediments, extraction phases and biological samples were established by ICP-MS. The collision reaction cell was employed to eliminate the polyatomic interferences arising from the environmental samples with complex matrixes. The analytical parameters (the instrument detection limits, the method detection limits, accuracy and precision) were proved to be satisfactory.In order to assess the heavy metal pollution in surface sediment, the distribution of sixteen heavy metal elements were determined in sediments at fourteen sampling stations in Jinzhou Bay. Metal contents in the sediments near the zinc plant effluent were higher than other samples. Meanwhile, the metals of Cd, Zn, Pb and Cu in the sediment samples were primarily associated with the non-residual fraction, and Cu, Zn, As, Pb and Cd were accumulated significantly in the research on bioaccumulation with Ruditapes philippinarum.After reviewing the many assessment methods used at home and abroad, several assessment methods were used for evaluating the pollution level of Jinzhou Bay in the present paper. The potential ecological risk of the sediment samples was serious in Jinzhou Bay, Cd, Zn, Pb, Cu and As were the primary contaminated elements in the sediment samples, and metals of Cd, Zn, Pb, Cu and As were suggested significant anthropogenic impact. The bio-available constituents of Cd/Zn fractions in the surface sediment was comprised of exchangeable and carbonate fractions, and Pb/As bio-available fractions were made up of non-residual fraction, the bio-available constituents of Cu fractions in the surface sediment was composed of exchangeable and organic matter fractions. In a word, Jinzhou Bay was a high ecological risk region.