Solubility control of Cu, Zn, Cd and Pb in contaminated soils
Solubility control of Cu, Zn, Cd and Pb in contaminated soils
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DOI：
10.1111/j.1365-2389.1997.tb00554.x
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发表时间：
1997-06-01
影响因子：
4.2
通讯作者：
Hendershot, W
中科院分区：
文献类型：
--
作者：
McBride, M;Sauve, S;Hendershot, W
我们根据金属络合理论建立了一个半经验方程，将土壤溶液的金属活度与土壤的 pH、有机质含量 (OM) 和总金属含量 (MT) 联系起来。方程的一般形式为：pM = a + bpH - c log(MTOM-1)，其中 pM 是金属活度的负对数（以 10 为底），a、b 和 c 是常数。该方程成功预测了具有多种特性的土壤中的游离 Cu2+ 活性，包括之前用污水污泥处理过的土壤。 pCu 与长期污染土壤中测量的土壤特性的显着相关性表明，铜活性是通过稳态条件下有机物的吸附来控制的。尝试根据单独发表的数据将土壤中的总可溶性铜、锌、镉和铅与土壤 pH 值、有机质含量和总金属含量相关联。对于铜，土壤总铜含量与总可溶性铜的相关性最高。同样，总可溶性 Zn 和 Cd 与总金属含量相关，但与土壤 pH 值的相关性比可溶性 Cu 的相关性更强。锌和镉对较高土壤 pH 值的金属溶解度较小，这些金属往往不会与可溶性有机物强烈络合。在根据土壤性质预测金属溶解度时，有机质含量通常（但并非总是）具有统计显着性变量。根据测量的土壤特性预测铅的溶解度不如其他金属的溶解度令人满意。至少对于铜来说，固体有机物似乎限制了游离金属的活性，而溶解的有机物则促进了金属的溶解度。在金属污染物成熟的土壤中。虽然总金属含量本身通常不能很好地预测金属溶解度或活性，但在比较具有相似 pH 值和有机质含量的土壤中的金属溶解度时，它具有非常重要的意义。
We developed a semiempirical equation from metal complexation theory which relates the metal activity of soil solutions to the soil's pH, organic matter content (OM) and total metal content (MT) The equation has the general form:pM = a + bpH - c log(MTOM-1),where pM is the negative logarithm (to base 10) of the metal activity, and a, b and c are constants. The equation successfully predicted free Cu2+ activity in soils with a wide range of properties, including soils previously treated with sewage sludge. The significant correlation of pCu to these measured soil properties in long-contaminated soils suggests that copper activity is controlled by adsorption on organic matter under steady state conditions. An attempt was made from separate published data to correlate total soluble Cu, Zn, Cd and Pb in soils to soil pH, organic matter content and total metal content. For Cu, the total Cu content of the soil was most highly correlated with total soluble Cu. Similarly, total soluble Zn and Cd were correlated with total metal content, but were more strongly related to soil pH than was soluble Cu. Smaller metal solubility in response to higher soil pH was most marked for Zn and Cd, metals that tend not to complex strongly with soluble organics. The organic matter content was often, but not always, a statistically significant variable in predicting metal solubility from soil properties. The solubility of Pb was less satisfactorily predicted from measured soil properties than solubility of the other metals. It seems that for Cu at least, solid organic matter limits free metal activity, whilst dissolved organic matter promotes metal solubility. in soils well-aged with respect to the metal pollutant. Although total metal content alone is not generally a good predictor of metal solubility or activity, it assumes great importance when comparing metal solubility in soils having similar pH and organic matter content.