Centre for Environmental Risk Assessment and Remediation, Building X, University of South Australia, Mawson Lakes, SA 5095, Australia.
J Hazard Mater. 2009 Nov 15;171(1-3):1150-8. doi: 10.1016/j.jhazmat.2009.06.124. Epub 2009 Jun 30.
We investigated the pore-water content and speciation of copper (Cu), zinc (Zn), cadmium (Cd) and lead (Pb) in a range of uncontaminated and long-term contaminated soils in order to establish their potential bioaccessibility to soil biota, plants and humans. Among the samples, soil pH (0.01 M CaCl(2)) ranged from 4.9 to 8.2. The total metal content of the uncontaminated soils ranged from 3.8 to 93.8 mg Cu kg(-1), 10.3 to 95 mg kg(-1) Zn, 0.1 to 1.8 mg Cd kg(-1) and 5.2 to 183 mg kg(-1) Pb, while metal content in the contaminated soils ranged from 104 to 6841 mg Cu kg(-1), 312 to 39,000 mg kg(-1) Zn, 6 to 302 mg Cd kg(-1) and 609 to 12,000 mg kg(-1) Pb. Our analysis of pore-water found the Cu concentrations to be much higher in contaminated soils than in uncontaminated soils, with the distribution coefficients (K(d)) correlating significantly with the log of dissolved organic carbon concentrations. Despite the high total metal content of the contaminated soil, Zn, Cd and Pb were not generally found at elevated levels in the pore-water with the exception of a single contaminated soil. A long period of ageing and soil weathering may have led to a substantial reduction in heavy metal concentrations in the pore-water of contaminated soils. On the other hand, Pb bioaccessibility was found to be comparatively high in Pb contaminated soils, where it tended to exceed the total Pb values by more than 80%. We conclude that, despite the extensive ageing of some contaminated soils, the bioaccessibility of Pb remains relatively high.
我们研究了一系列未受污染和长期受污染土壤中的孔水含量和铜（Cu）、锌（Zn）、镉（Cd）和铅（Pb）的形态，以确定它们对土壤生物、植物和人类的潜在生物可利用性。在这些样本中，土壤 pH 值（0.01 M CaCl2）范围从 4.9 到 8.2。未受污染土壤的总金属含量范围从 3.8 到 93.8 mg Cu kg-1、10.3 到 95 mg kg-1 Zn、0.1 到 1.8 mg Cd kg-1 和 5.2 到 183 mg kg-1 Pb，而污染土壤的金属含量范围从 104 到 6841 mg Cu kg-1、312 到 39,000 mg kg-1 Zn、6 到 302 mg Cd kg-1 和 609 到 12,000 mg kg-1 Pb。我们对孔水的分析发现，污染土壤中的 Cu 浓度远高于未受污染土壤，分配系数（Kd）与溶解有机碳浓度的对数显著相关。尽管污染土壤的总金属含量很高，但 Zn、Cd 和 Pb 通常不会在孔水中升高，除了一个污染土壤。长时间的老化和土壤风化可能导致污染土壤中重金属浓度的大幅降低。另一方面，我们发现 Pb 污染土壤中 Pb 的生物可利用性相对较高，其超过总 Pb 值的比例超过 80%。我们得出结论，尽管一些污染土壤已经老化很久，但 Pb 的生物可利用性仍然相对较高。
