School of Resources and Environmental Engineering, Anhui University, Anhui Province Engineering Laboratory for Mine Ecological Remediation, Hefei, 230601, Anhui, China.
School of Resources and Environmental Engineering, Anhui University, Anhui Province Engineering Laboratory for Mine Ecological Remediation, Hefei, 230601, Anhui, China.
Environ Pollut. 2022 Sep 1;308:119613. doi: 10.1016/j.envpol.2022.119613. Epub 2022 Jun 12.
The most prominent source of Cu contamination in soils is metal mining and processing, partly since the Middle Age. However, coal mining and combustion can also cause (some) Cu contamination. We studied the distribution of Cu concentrations and isotope ratios in soils of the Huaibei coal mining area. The contribution of the coal mining and combustion to total Cu concentrations in soil was determined with a two-end-member mixing model based on the distinct δCu values of the Cu emitted from coal mining and combustion and in native soil. The mean Cu concentration of 75 mg kg exceeded the local soil background value (round to 22.13 mg kg). The similar δCu value of grass near the coal mining and combustion operation as in gangue and flying ash indicated a superficial Cu contamination. Mining input was the dominant source of Cu in the contaminated soils, contributing up to 95% and on average 72% of the total Cu in the topsoils. The mining-derived Cu was leached to a depth of 65 cm, where still 29% of the Cu could be attributed to the mining emissions. Grasses showed lower δCu values than the topsoils, because of the preferential uptake of light Cu isotopes. However, the ΔCu was lower in the contaminated than the uncontaminated area because of superficial adsorption of isotopically heavy Cu from the mining emissions. Overall, in this study the distinct δCu values of the mining-derived Cu emissions and the native soil allowed for the quantification of the mining-derived Cu and had already reached the subsoil and contaminated the grass by superficial adsorption in only 60 years of mining operation.
土壤中铜污染的主要来源是金属采矿和加工，部分源自中世纪。然而，采煤和燃烧也会导致（部分）铜污染。我们研究了淮北采煤区土壤中铜浓度和同位素比值的分布。基于采煤和燃烧过程中排放的铜与原生土壤之间明显的 δCu 值，利用双端元混合模型确定了采煤和燃烧对土壤中总铜浓度的贡献。75mgkg 的平均铜浓度超过了当地土壤背景值（约为 22.13mgkg）。采煤和燃烧作业附近草的 δCu 值与矸石和飞灰相似，表明存在表面铜污染。采矿输入是污染土壤中铜的主要来源，在表层土壤中高达 95%，平均 72%的铜来自采矿。采矿衍生的铜被淋滤到 65cm 的深度，其中仍有 29%的铜可归因于采矿排放。由于优先吸收轻铜同位素，草的 δCu 值低于表层土壤。然而，由于采矿排放的同位素较重的铜的表面吸附，污染区的 ΔCu 值低于非污染区。总的来说，在这项研究中，采矿衍生铜排放物和原生土壤的明显 δCu 值允许定量确定采矿衍生铜，并且仅在 60 年的采矿作业中，就已经到达亚土层并通过表面吸附污染了草。
