Study On The Distribution And Pollution Condition Of Major And Trace Elements In Eastern Dongting Lake Lakeshore Zone

Lakeshore Zone is one of the most natural protective barrier to Eastern Dongting Lake. Because of the rapid development of urbanization, developing mining and industry production, Breeding industry production in nearly two decades, a tremendous amount of waste was discharged to the lake resulting in serious soil pollution problems. The distribution characteristics and combination characteristics of 10 kinds of major elements and 19 kinds of trace elements were analyzed in Eastern Dongting Lake Lakeshore Zone. On this basis, the multivariate statistical method was applied to reveal the occurrence characteristics and pollution sources of trace elements in soil. At the end, taking the soil geochemical baseline as the contrast parameters, the Enrichment Factor and Geoaccumulation index methods were applied to assessing the soil pollution, in order to provide a reliable reference for the soil pollution in Eastern Dongting Lake Lakeshore Zone.The main conclusions were summed up as follows:1. Lakeshore Zone soil of Eastern Dongting Lake were mainly composed of silicate minerals.Compared to the average value of Chinese soil, TFe2O3 and V elements expressed as relative enrichment in all of the major and trace elements. The content of the major elements and 8 trace elements(Co、V、Nb、Cu、 Ni、Cr、Sr、Zr) in farm of Tuanzhou、Reed Field of Lu Lake and Seven teams reserve area was higher than other functional areas; The content of elements (Sb、sBi、Mo、Sn、As、Hg、 Cd、Pb、Zn、Ba、Rb) in Lujiao port area、Yueyang urban area and Chenglingji port area was generally higher than other functional areas. The vast majority of major and trace elements appeared to migrate to the lower layers of the soil in the urban area of Yueyang and Chenglingji port area, which affected by human activities.2. The multivariate statistical method was applied to reveal the occurrence characteristics of trace elements in Lakeshore Zone soil, the results showed that Ni、V、Cr、Co、Nb、Cu mainly hosted in ilmenite and Magnesium oxide of iron; Rb、Ba may be conferred in the clay mineral and Potassium feldspar minerals; Pb、Z、As、Cd、Hg、Bi、 Sn、Sb may be endowed to Apatite and manganese minerals, however may be mainly conferred presence of other minerals; Sr hosted in Calcium and sodium feldspar; while Zr、Mo and discussion minerals no significant occurrence relations, may be conferred presence of other minerals. Using the factor analysis researched pollution sources of trace elements in Lakeshore Zone soil, the results indicated that Co、V、Nb、 Ba may be mainly came from parent material of soil and slight agricultural activity; Bi、Sn may be mainly derived from transportation and industrial activity; Sb may be mainly came from river basin upstream of the mining production; Sr、Zr may be derived from natural minerals; Mo showed special independence, that Pollution source needed further research.3. Taking the soil geochemical baseline as the contrast parameters, the Enrichment Factor method was applied to assessing the pollution of trace elements in Lakeshore Zone soil. The obtained results showed that Bi belonged to moderate pollution level, Sn、Cu、 Ni、Cr were classified to zero-light pollution level, other elements belonged to light pollution level, the most polluted area included Reed Field of Lu Lake、Lujiao port area、Yueyang urba area and Chenglingji port area, the main pollution elements contained Sb、Bi、Sn、Zr、Ba、As、Hg、Pb、Zn. Using geoaccumulation index method evaluated the pollution of trace elements in Lakeshore Zone soil, the research result was broadly in line with the study results of enrichment factor. Choosing Dongting Lake background as the contrast parameters, the obtained evaluate results of soil trace elements on the basis of geoaccumulation index method showed that Sb、 Bi、Sr、Z、Ba、Mo、Sn belonged to light pollution level, Co、V、 Nb were classified to zero-light pollution level.Therefore, selecting different reference value, it had a big difference on the Pollution type and pollution elements.Choose the geochemical baseline for reference, avoiding the regional background values without considering the influence of human activities, making the evaluation results more practical significance.