| Cu is one of the most important metal materials in modern industry. In recent years, with the help of high copper price, another round of copper-mining and smelting have arisen. The mineral resources exploitation has brought huge profits to local residents but a series of environmental geological problems caused by mining resources exploitation, such as the environmental pollution, the destroy of resources and environments. Heavy metals are one of the kinds of contaminations, which go along with mine exploitation and exist extensively. They have been focused by many studies because they can produce deep and long-lasting effect on environment and are prone to biological concentration and more harmful. The Dahongshan copper is a famous copper-rich mine in our country, which is richer in reserves, higher grade and better investment benefit. Now, the copper has entered into the phase of rapid development and the enterprise scale unceasingly expands. Accompanying to product economic interest it can offer some harm for nature, which has brought much worry to people. Now, the studies of the state of the environment about the area are fewer. Above all, the problems of heavy-metal-contaminated environment are worth researching.In this paper, the quality of the water and sediment in rivers and soils around the copper is studied and the distribution character of heavy metal (including copper, chromium, cadmium, lead, zink and nickel) in overlying water, sediments and soil around the Dahongshan copper was studied as a whole. Contamination by heavy metal was discussed based on their characteristics of forms, transit and accumulation between mediums Contaminant's function mechanism and influence factor were explored. The pollution situation around the Dahongshan copper was evaluated and found out the sensitive regions of ecology around the copper. The study results are as follows.1. Heavy metal pollution in environment around the Dahongshan copper is more or less, especially, Cu and Cd. In overlying water, the concentrations of Cu in Laochang river, the concentrations of Cu and Cr in Mangan river and Hunlong river, the concentrations of Cu in Laochang river, the concentrations of Pb and Zn in Feiwai river and Cr in Jiasa river are higher and exceed the I criterion of environmental quality for surface water The metal concentrations in surface sediments distributed as follow: the concentration of Cu is higher than others in Hunlong rive, the concentration of Cd and Ni in Laochang river, the concentration of Cr in Jiasa rive and the concentration of Zn in Feiwai river are higher than others. The concentrations of most metals are higher in sediments of Mangan river. The main pollution element in sediments is Cu, which exceed the II criterion of environmental quality for soil. The concentrations of Cd and Ni in some samples and exceed I criterion. The metals of Cr, Pb and Zn in surficial sediments show no pollution.2. The distribution character of the concentration of Cu,Cr,Cd,Pb,Zn and Ni in water show: The higher concentration of them in Mangan river, which is closer to the copper and lower concentration in Jiasa river, which is furthermost. What′s more, concentrations of Cu, Cd, Pb and Zn, are higher respectively in three other rivers. This indicate that the distribution of the concentrations of heavy metals is influenced by the copper strongly. The concentrations of heavy metals in water of rivers reduce with the river faring away from the copper. And it also shows that those sporadic small mines play some part in the diversity distribution of the concentration of Cu,Cr,Cd,Pb,Zn and Ni.3. The study indicates that with water fluent, the Laochang river and Feiwai river have biggest contribution to the heavy metal pollution of Hunlong river. The contribution of Laochang river to Hunlong River for Cu and Cr every year is 0.67 t and 0.71 t. The contribution of Feiwai river very year is0.66 t Pb, 3.85 t Zn, and 0.18 t Ni. But the Hunlong river′s metals are the source of heavy metals for Jiasa river. The contribution very year is 2.32 t Zn, 0.91 t Cr, and 0.53 t Cu.4. The distribution character of the concentration of Cu,Cr,Cd,Pb,Zn and Ni in soils around the Dahongshan copper shows: The concentrations of Cu and Cd in soils around Mangan river and Laochang river, which are closer to the copper are higher. The concentrations of Cr and Ni in Feiwai orchard soils are higher. The concentration of Pb in Jiasa vegetable soils is higher. Metal concentrations in Hunlong paddy field soils are lower. In all, degree of contamination influenced by different land-utilization Is mine exploitation > orchard > vegetable > paddy field. 5. The metal speciation analysis result is as follows. Speciations of heavy metal in sediments and soils are similar. Residual metal has a most proportion. Amoung extractive forms, Cr and Cd are mainly associated with exchangeable form; Pb is mainly associated with iron and manganese oxides form; In sediments, Zn is mainly associated with iron and manganese oxides form, while in soils is mainly associated with carbonates form; Cu is mainly associated with organic form.6. The primary evaluation of heavy metal contamination by Plant-monitoring and IR indicates that heavy metals in sediments and soils are toxic to vegetables. The ecological shelter zone is seriously threatened by Cu and Cd, including Laochang river, Mangan river and Hunlong river. Feiwai river and Jiasa river are mainly threatened by Cd and Pb.7. There several sensitive regions of ecology around the copper including middle portion of Mangan river, lower reaches of Laochang river, the join of Mangan river and Laochang river and Hunlong river. It maybe have something with the run of the mine. |
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