Department of Earth and Environmental Sciences, Korea University, Seoul 02841, the Republic of Korea.
Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA; Bulgarian Academy of Sciences, Institute of Chemical Engineering, Sofia 1113, Bulgaria.
J Hazard Mater. 2022 Sep 15;438:129422. doi: 10.1016/j.jhazmat.2022.129422. Epub 2022 Jun 20.
Assessment of Zn toxicity/mobility based on its speciation and transformations in soils is critical for maintaining human and ecosystem health. Zn-concentrate (56 % Zn as ZnS, sphalerite) has been imported through a seaport and transported to a Zn-smelter for several decades, and smelting processes resulted in aerial deposition of Zn and sulfuric acids in two geochemically distinct territories around the smelter (mountain-slope and riverside). XAFS analysis showed that the mountain-slope soils contained franklinite (ZnFeO) and amorphous (e.g., sorbed) species of Zn(II), whereas the riverside sediments contained predominantly hydrozincite [Zn(OH)(CO)], sphalerite, and franklinite. The mountain-slope soils had low pH and moderate levels of total Zn (~ 1514 ppm), whereas the riverside sediments had neutral pH and higher total Zn (12,363 ppm). The absence of sphalerite and the predominance of franklinite in the mountain-slope soils are attributed to the susceptibility of sphalerite and the resistance of franklinite to dissolution at acidic pH. These results are compared to previous Zn analyses along the transportation routes, which showed that Zn-concentrate spilled along the roadside in dust and soils underwent transformation to various O-coordinated Zn species. Overall, Zn-concentrate dispersed in soils and sediments during transportation and smelting transforms into Zn phases of diverse stability and bioavailability during long-term weathering.
基于土壤中锌的形态和转化来评估锌的毒性/迁移性对于维护人类和生态系统的健康至关重要。几十年来，锌精矿（56%的 Zn 为 ZnS，闪锌矿）一直通过海港进口，并运至一家锌冶炼厂，冶炼过程导致锌和硫酸在冶炼厂周围两个地球化学性质截然不同的地区（山坡和河边）进行空气沉积。XAFS 分析表明，山坡土壤中含有铁锌尖晶石（ZnFeO）和无定形（如吸附）的 Zn(II)物种，而河边沉积物中主要含有碱式碳酸锌 [Zn(OH)(CO)]、闪锌矿和铁锌尖晶石。山坡土壤的 pH 值较低，总锌含量适中（约 1514ppm），而河边沉积物的 pH 值呈中性，总锌含量较高（12363ppm）。山坡土壤中没有闪锌矿，而铁锌尖晶石占主导地位，这归因于闪锌矿易溶解，而铁锌尖晶石抗酸性 pH 值溶解的能力。这些结果与之前在运输路线上进行的锌分析进行了比较，结果表明，锌精矿在路边洒落的粉尘和土壤中，在运输和冶炼过程中会转化为各种 O 配位的 Zn 物种。总的来说，锌精矿在运输和冶炼过程中散布在土壤和沉积物中，在长期风化过程中会转化为各种稳定性和生物可利用性的 Zn 相。
