Research On Heavy Metal Pollution And Source Of Material Analysis In Sediment Of Dalian Bay

Dalian 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 ten surface ten surface and four core sediment samples collected in Dalian Bay and four core sediment samples collected in Dalian Bay,15heavy metals and15rare earth elements contents in the samples were determined, and the assessment of heavy metals pollution and analysis of sources of materials of sediment also discussed in this paper. The main content of the present paper as following:Methods for of heavy metals and Rare earth elements determination in sediments was 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 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,Ten surface sediment samples and four core sediment samples collected in Dalian Bay for the heavy metals and REEs determination. The distribution of heavy metal in the surface sediment shown that the content of the heavy metals in the sites of S1、S2、 S4、S5and S9was much higher than other sites, that almost located in the near shore area. The vertical distribution of the heavy metals in the core sediment shown that in the upper layer sedi ment had higher metal content in the sites of F1and F3, and conversely, F2and F4had higher metals content in the lower layer sediment.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 Dalian Bay. Cd, Zn, Pb, Cu and As were the primary contaminated elements in the sediment samples, and Cd, As were suggested significant anthropogenic impact. The assessment result shown that the sites of S1、S2、S4、S5were polluted serious.The content of LREE, HREE and its ratios was changed greatly, but theδCe andδEu had little change in the surface and core sediment in Dalian Bay. The content of LREE, HREE and its ratios may be used for analysis source of sediment material. The enrich factor of REEs shown that sediment of Dalian bay was land based sources, and had close correlation with Al that usually Coexistence of clay minerals.