The Study Of Cadmium Pollution In Local Zinc Smelting With Indigenous Method

As a highly toxic and mobile metal, cadmium attracts the most environmental attention worldwide. Recently, local zinc smelting with indigenous methods in Guizhou province become more and more serious because of higher Zn prices. Till recent years(up to 2005), artisanal zinc smelting activities have been completely ceased due to the concerns of environmental protection. But, the cadmium which produced by indigenous methods will harm to human being along the food chain. Therefore, the heavy pollution from those indigenous stoves posed increasing environmental concerns.Guizhou Province is rich in lead and zinc resources, and Liupanshui city, owning to its massive high quality coals, which enables it as one of areas of high zinc smelting activities. In order to assess the environmental impacts and geochemistry of those indigenous methods, this paper focus on the typical region which used zinc smelting with indigenous method in Tangshangbazi, Shuicheng county, Liupanshui city, Guizhou province. While estimated the soil pollution and local atmospheric TSP correlational dependence, Moss Bags technology had been used to monitor the dry and total deposition of Cd, further explained atmospheric TSP as well as the aerosol which led to the soil pollution.1. Cadmium pollution in soilsBased on the above reasons, aimed at pollution situation of soil in the area of zinc smelting with indigenous method, we investigated concentration and distribution characteristics of cadmium in agricultural land of this region by means of spot check, distribution characteristics of cadmium in typical agricultural land of this region were analyzed by Kriging method. As a result, distribution map of this heavy metals was obtained, which could directly reflect pollution situation of heavy metals in different areas. So we could provide scientific basis for protection of agricultural environment in this area, and control of agricultural non-point source pollution, as well as safeguard to agricultural products.The results indicated that the soils had been seriously contaminated by the cadmium, which mainly caused by mine-wastes and elemental cadmium vapor. The cadmium concentration in soils range from 2.669 to 12.64mg/kg, which was 1.68~ 7.95 times higher compared with background concentration of cadmium in Liupanshui city(1.59mg/kg), and it was 44.48~210.67 times higher than worldwide mean value(0.060mg/kg).2. Cadmium concentration in TSP, dry and total deposition of CdObviously, the cadmium in atmospheric TSP has been influenced seriously by the activities. It contained the cadmium as high as 129.4mg/kg near the smelting furnace. In the place of downward the prevailing wind 10km, it contained the cadmium which still reached to as high as 27.29 mg/kg, and the smelting waste gas was a cadmium important resource in atmospheric TSP.Dry and wet deposition of element cadmium was measured by Moss Bags in...