云南酸控区土壤重金属释放特征及潜在风险

Release Character and Potential Risks of Heavy Metals in Soil of Acid Rain Control Zone,Yunnan Province

研究了云南省酸雨控制区3种土壤重金属Pb、Zn、Cu在模拟酸雨淋溶作用下的释放特征,并进行了酸雨淋溶前后的潜在风险评价。结果表明,重金属在模拟酸雨作用下很快溶出,约30h后趋于平稳,3种重金属Pb、Zn、Cu最大累计释放量分别为102.32、52.19和70.54mg/kg。不同pH下重金属的溶出趋势基本相同,重金属的释放量均随酸雨的降低而增加。由潜在风险评价可知,3种重金属污染程度为Pb>Cu>Zn,且重金属经酸雨淋溶后危害程度增加。指数表明酸雨淋溶前后种重金属综合潜在生态危害均为轻微生态危害,但区域性危害较重。

This paper studied release characters of Pb、Zn and Cu in soil of acid rain control zone under simulated acid rain conditions. Potential risks were assessed before and after leached by simulated acid rain. The results showed that heavy metals were extracted quickly and the extracting contents tended to stability after 30h. The accumulative extractionl volumes of Pb、Zn and Cu were 102.32、52.19 and 70.54 mg/kg, respectively. Different heavy metals extracting displayed the same tendency under different pH conditions. The heavy metals extraction gradually rised with the decrease of pH values. Potential risks assessment indicated that the pollution extent of 3 heavy metals was Pb CuZn and the hazardous extent of Pb increased after leaching of acid rain. Indexes revealed that the integrated potential risks of 3 heavy metals belonged to the slight ecological hazard ,but the regional harm was serious.