【作者】 许玉萍；

【导师】 周涛发；

【作者基本信息】 合肥工业大学 ， 环境科学， 2009， 硕士

【摘要】 铜陵矿区是我国七大矿集区之一,区内矿产资源丰富,但大量的矿产资源的开发、冶炼和运输过程及由矿石开采而产生的尾矿废石的堆积导致矿区内土壤富集了较高含量的重金属,而重金属一旦进入土壤后,则会通过食物链或通过某些迁移方式进入水和大气中,从而威胁人类的健康和其它动物的繁衍,且重金属污染的土壤具有隐蔽性、不可逆性和长期性、后果的严重性三大特点,因此,治理重金属污染的土壤是目前国内外所关注的热点和难点的研究课题。本论文选择铜陵新桥矿区土壤为主要研究对象,通过对土壤理化性质和XRD测试,分析了本底重金属铜的形态以及外源重金属进入土壤后土壤中重金属的转化。并将外源重金属处理的土壤经有机酸处理后土壤中重金属形态分布与未经有机酸处理的土壤中重金属形态分布的对比。得出的主要结论如下:新桥矿区的土壤为弱酸性土壤,有机质含量较低,土壤中的矿物组成以石英为主,其次为伊利石和高岭石,土壤中铜和镉的浓度也很高,远远高于土壤背景值。原土Cu的形态分布以残渣态为主(约占55.37%),其余各形态组分含量从大到小为依次为:Fe-Mn氧化物结合态、腐殖质结合态、强有机结合态、碳酸盐结合态、可溶态。外源Cu进入土壤后,随着外源Cu的浓度的增加,残渣态百分含量降低,可溶态百分含量增加。但其他四种形态的所占的百分含量大小顺序未变。外源Cd进入土壤后,土壤中Cd以可溶态为主。碳酸盐结合态、腐殖质结合态、Fe-Mn氧化物结合态和强有机结合态随着外源Cd浓度的增加,他们的百分含量也在不断变化,残渣态百分含量随外源Cd浓度的增加而降低。有机酸进入土壤后,不同浓度和不同种类的有机酸对重金属的作用不同,其中DTPA对各个处理的土壤中的Cu都有较好的活化作用,随着外源Cu浓度的增加,对于土壤中的Cu有活化作用的有机酸越来越多。虽然有机酸对外源Cd污染的土壤中的Cd也有一定的活化作用,但较Cu而言,其活化作用较弱,且当外源Cd浓度达到100mg/kg和130mg/kg时,1mmol/kg的有机酸活化效果更明显。更多还原

【Abstract】 Tongling Mining area is the one of the seven largest mining areas in China. It is rich in deposits resources, yet heavy metals greatly accumulated in soil of the area with the activities like mine exploitation, smelting, transportation, and tailing disposal. After heavy metals entered into soil, it would also transfer to water and air through food cycle, accordingly threatened the public health and ecology. Since the heavy metal pollution has the feature of concealment, irreversibility, and chronicity, it is widely concerned domestically and abroad as a difficult issue.Selecting Xinqiao Area in Tongling as study area.we measured the physico- chemical properties and the XRD of the soil, subsequently analyzed the CK of Cu in soil, and the transformation of the heavy metal status after added external heavy metals. Besides, Comparison study was conducted between the status of heavy metals in polluted soil with organism acid added and that without organism acid. We draw the conclusions as following.The soil in Xinqiao Area is weak acidic with low content of organism. It is composed with largest percentages of quartz, followed by illite and kaolinite. The Cu and Cd concentration is high, significantly exceeding background values.Adsorption and desorption of soil to heavy metal increases as more heavy metals added. The adsorption rate to Cu decreased at first, and then increased. In a whole, adsorbed Cd increases with the concentration of Cu added, so does the absorbed rate.Residual fraction is the most component of Cu in original soil (about 55.37%). The content order of the other fraction are following Fe-Mn oxide-bound fraction, humic -bound fraction, organic-bound fraction, carbonate-bound fraction,and dissoluble fraction is the lowest.After external Cu entered soil, The percentage of residual fraction declines, and that of dissoluble Cu increases. The percentages of other four components do not change in sequent. After external Cd entered soil, dissoluble Cd became the majority. Carbonate-bound fraction, humic-bound fraction, Fe-Mn oxide-bound fraction, organic-bound fraction changes with the concentration of Cd added. While the residual fraction is the lowest with a decreasing trend.After organic acid added into soil, different types of organic acid with different concentrations influent heavy metals distinctly. DTPA behaves effectively in activation of soil Cu. With higher external Cu added, soil Cu becomes more active requiring less organic acids. Organic acid can activate soil Cd in some extent, but the function is weaker than Cu.and when the concentration of added Cd reach 100mg/kg and 130mg/kg, the activation of 1mmol/kg organic acids is much more obvious.更多还原