TCLP法评价泉州市大气降尘重金属的生态环境风险

Assessment of Toxicity of Heavy Metal Contaminated Dustfall in Quanzhou City by Toxicity Characteristic Leaching Procedure

对泉州市不同功能区大气降尘中的重金属(Cu、Zn、Pb、Cd、Cr、As、Fe、Mn、Co、Ni、V)含量进行了分析测定,采用由美国环保署(USEPA)提出并被广泛推荐采用的TCLP法对泉州市不同功能区大气降尘中的重金属元素(Cu、Zn、Pb、Cd、Cr)的生态环境风险进行评价。以TCLP法提取的泉州市大气降尘重金属Cu、Cd、Zn、Pb、Cr、As、Fe、Mn、Co、Ni和V含量分别在2.592～63.20、0.084～2.978、9.276～3141、0.147～345.0、0.628～9.696、0.019-5.152、5.037-248.9、55.00-1261、0.040-63.56、0.735-37.43和0.020-24.07 mg/kg之间。根据TCLP法测定项目的法定阈值,泉州市大气降尘不同程度地受到Cu、Zn、Pb、Cd、Cr的污染,其中以Pb、Zn污染最为严重,其次为Cu、Cd、Cr。相关性分析结果显示,Fe、Mn、Ni、Cr、V的TCLP法提取量受样品pH值的显著影响;Pb、Cd、Mn、Co、Ni、As提取量除了受金属本身的总量影响外,还受到其它元素总量和TCLP提取量的影响。主成分分析结果表明,交通尾气尘、燃油尘、装饰材料尘、地面土壤尘、工业粉尘、建筑尘和燃煤烟尘等是泉州市大气降尘的主要来源,占总贡献率的86.01%。

Contents of heavy metals （Cu, Zn, Pb, Cd, Cr, As, Fe, Mn, Co, Ni and V） in dustfall collected from different zones of Quanzhou city were analyzed. The ecological risk of some heavy metals （Cu, Zn, Pb, Cd and Cr） was assessed by the Toxicity Characteristic Leaching Procedure （TCLP）, which was developed by USEPA and commonly recommended to be used to evaluate the environmental risk of solid wastes. The available levels of Cu, Zn, Pb, Cd, Cr, As, Fe, Mn, Co, Ni and V from dustfall of Quanzhou city are 2.592-63.20, 0.084-2.978, 9.276- 3141, 0.147-345.0, 0.628-9.696, 0.019-5.152, 5.037-248.9, 55.00-1261, 0.040-63.56, 0.735-37.43 and 0.020-24.07 mg/kg, respectively, based on TCLP method. According to the regulatory levels of heavy metals, most dustfall of Quanzhou city has been polluted by Cu, Zn, Pb, Cd and Cr, in which Zn and Pb were the most serious polluting elements, followed by Cu, Cd and Cr. The results of correlation analysis show that the TCLP-extraction contents of Fe, Mn, Ni, Cr and V are significantly influenced by pH values of dustfall samples. The TCLP-extraction contents of Pb, Cd, Mn, Co, Ni and As are correlated with not only their own total contents but also the total and TCLP-extraetion contents of other elements in the dustfall. The results of principal component analysis show that traffic emission, oil burning dust, decoration material, surface soil dust, industrial dust, construction dust and coal burning dust are dominant sources for the dustfall in Quanzhou City with the total contribution of 86.01%.