The Pollution Of Heavy-Metal Elements To The Xiangsi River And Its Around In Tongling, Anhui

The paper takes the sediments and water in the Xiangsi River and the around soils in Anhui Tongling City as its main researching objects. Then the paper develops the contamination research of the heavy-metal elements to explore the geochemistry behaviors of heavy-metal elements produced by the mining activities and their influence. The main contaminations in this area are the Fenghuangshan Copper Mine in upriver and the Xinqiao Pyrite in middleriver. The paper first chooses several representative soil samples to research the distributing in different granularities of four main heavy-metal elements, and the modes of occurrence of the heavy metal elements in different granulatiries are studied adopting the improved sequential speciation separation method of Tessier(1979) and Fortsner. The contents of the heavy metals in different states are surveyed. The paper finds that the contents of heavy-metal elements in the big granulatiries are similar as in the small granulatiries, and the heavy-metal elements in the soils mainly occur in the slag phase, Fe-Mn oxidation phsae and organic phase. Then the transferring patterns and distributing rules of the heavy metal elements in the soils around the Xiangsi River are confirmed. Then the paper analyzes the contamination of the heavy-metal elements of sediments in the Xiangsi River, the results indicate the contents of Cu Zn Cd As all excess the secondary quality standard of our country. The method of potential ecological risk index presented by Hakanson is used to assess the heavy metals' ecological risk. The results show that the Cd, Cu, As and Pb of the analyzed elements have caused serious and very serious ecological risk, and the contamination of Cd and Cu is the most. The contamination in downriver is more serious. The paper also analyzes the heavy-metal elements of the water in the Xiangsi River. Each monitored sections has been caculated and compared by the intimated method, and the pollution degree of the monitored sections of the polluted river is C₁24356. The concentration of the heavy metals primarily presents the ascending trend. The sediments and water in Xiangsi River and the around soils have been seriously influenced by the mining activities combining the areal geologic background and the mining activities in this area. There are much SO₄²- in the river, and the water presents acid to weak acid for the existence of the Xinqiao Pyrite. Cd enriches distinctly in the downriver, its pollution is very serious.