Research Of The Selenium-rich Area In Guichi Associated With Heavy Metals And Its Biological Effects

In the natural environmental, selenium is a dispersion elements, and the distribution insoil environment is not uniform throughout the world, thus formed different selenium-richband and selenium deficiency area. Our country is a selenium deficiency in most parts ofcountry, soil selenium deficiency, and nearly two thirds of the population there existsdifferent degree of selenium inadequate intake. In the present situation, carries on thereasonable and safe to fill selenium, not only satisfy the demand of human selenium at thesame time, they can protect human physiology health is of great significance, no doubt,selenium biological transformation is a good way. Soil solicitation bioconversion againthrough the food chain transmission enter human body of selenium, is to obtain sufficientselenium safe and effective source of selenium. So as a rare natural selenium-richresources for the area, for biological provides superior selenium natural resources, and thenatural form for our country selenium research and development and utilization createdgood condition.Soil selenium resources development must pay attention to safety issues, with soilselenium in soil-biological systems migration, heavy metals also can pass along the foodchain, and the content of soil heavy metal, distribution and migration efficiency ofselenium-rich agricultural products will also have an important impact on the security.Because of heavy metals in the soil will continue to desegregate and nature is stable anddegraded, can pass the food chain crop production and quality harm to human body health,eventually produce unfavorable effects. Therefore, in selenium-rich soil in the use ofresources should have always pays attention to the potential harmfulness heavy metal.The Guichi area in Chizhou of Anhui province has a broad prospect of developmentof selenium-rich resources, develop guichi area selenium-rich resources research forimproving regional human body is of great significance to selenium levels. Butdevelopment soil selenium resources must simultaneously comprehensive consideration ofheavy metals is harmful to human health, this paper content and distribution of soilenvironmental and biological (rice) samples of selenium and heavy metals As, Cd, Hgcontent characteristics and distribution law, discusses the research of selenium and heavymetals research in enrichment characteristics, and through the correlation analysis betweenthe heavy metal content with Se the inner link, then, based on the geological cumulativebynemero index method, the synthetic index method, and the combination of attempts toevaluate zone will be heavy metals pollution situation and pollution degree; And using gray correlation analysis method of heavy metal and Se judge connection degree size;According to selenium-rich soil heavy metal pollution characteristics of rice rhizospheresoil and Se and the heavy metal content in the seeds are analyzed, thus to research area Seand heavy metal biological utilization of the preliminary assessment and migration features,so as to provide se-enriched resources development in basic research. The main researchresults are as follows:1, The space distribution features of the heavy metals with As, Se Cd, HgResearch in selenium-rich soil containing selenium amount of0.589mg/kg mean,defined as a selenium-rich regions, its regional distribution mainly for autumn PuHecoastal regions and mountain foothills southeast respectively in tertiary river alluvialmaterial developed by the bedrock weathering formation and sediments and widedistribution. In the soil profile, selenium distribution characteristics of clusteringperformance for the table type. Morphological analysis shows that: humic acid state, strongorganic configuration, devris state selenium is the most main existence form.Soil heavy metal with soil selenium levels in Cd, the spatial distribution of soil qualitystandards are consistent with Ⅲ Ⅲ kind, super class level soil distribution for the Lord;As to Ⅰ, Ⅱ type of soil is given priority to, distributed in the central,southeastern andthe area north of Qiupu river; Employed by Hg elements are mainly Ⅰ type of soil widelydistributed, other levels soil content rarely. The soil profile Cd, Hg content has increasedwith soil depth decreases, and As instead, and comparison with As,Hg,the Cd surfaceenrichment trends are obvious.2, The biological effects of As, Se Cd, Hg with heavy metals in the areaThrough the research area and the corresponding rice rhizosphere soil collection andanalysis, sufficient selenium levels above the number of total samples sample52.56%,selenium-rich level above19.23%, and there is no lack of horizontal samples; Rice seedsmetals in pollution levels small, while employed by Hg Cd in general is not clearlybiological pollution, but As high content, exceeds80%of total samples samples. In therhizosphere soil selenium mostly Se content, arithmetic average for more than limits0.514mg/kg, has reached selenium-rich standards; Rhizospheric soil heavy metal pollutioncondition inherited surface for heavy metal content characteristic, expression is Cdpolluting content exceeds bid.The heavy metal content in plant with soil heavy metal content have particularconcern, also depends on the ability of heavy metal concentration plant, biologicalenrichment coefficients size order: Cd＞Se＞Hg＞As, which show that As Cd in rice seeds of high concentration ability. And the correlation analysis shows cadmium-selenium is stronger, the interaction between phenomenon accompanied significantly.3, Selenium-rich area of heavy metal pollution evaluationBased on geological cumulative bynemero index method, the synthetic index methodand geological cumulative-nemerow index method of comprehensive evaluation resultcomparison, the majority of soil samples by certain degree heavy metals pollution ofcollaborative pollution, in mild, three kinds of pollutants in scope than Cd is highest, andSe contribution is the largest also connection degree.