Characterization of Pb-Bearing Minerals in Polluted Soils from Closed Mine Sites

• Published in: Water, air, and soil pollution Vol. 231; no. 4
• Main Authors: Hoshino, Mihoko, Zhang, Ming, Suzuki, Masaya, Tsukimura, Katsuhiro, Ohta, Masaaki
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.04.2020; Springer; Springer Nature B.V
• Subjects: Acetates; Acetic acid; Atmospheric Protection/Air Quality Control/Air Pollution; Bearing; Classification (sedimentation); Climate Change/Climate Change Impacts; Colour; Copper; Diffraction; Earth and Environmental Science; Environment; Environmental monitoring; Galena; Heavy metals; Hydrogeology; Leaching; Lead; Minerals; Pollution; Powders; Remediation; Sodium; Sodium acetate; Soil; Soil contamination; Soil pollution; Soil remediation; Soil Science & Conservation; Soils; Sulfur compounds; Water Quality/Water Pollution; X ray powder diffraction; X rays; X-ray diffraction; X-ray diffraction analysis; Zinc; Lead; Mineralogical characterization; Sedimentary hydro-classification; Polluted soils; X-ray diffraction analysis; Soil contamination
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-020-04548-4

Lead is a toxic metal, and its characterization in contaminated soils is crucial to the success of a remediation, especially for the soil washing, one of most commonly used technologies. In this study, we propose a convenient approach that combines sedimentary hydro-classification with semi-quantitative powder X-ray diffraction analysis for characterizing the Pb-bearing minerals in soils. The approach was applied to two samples (YYm and YYu-1) collected from a closed Cu–Pb–Zn mine in the Tohoku region of Japan. The samples were taken from adjacent areas but had different appearances (YYm was a gray soil and YYu-1 was a creamy colored soil). The coarser YYm fractions had higher Pb contents than the finer YYm fractions, but the finer YYu-1 fractions (diameters < 32 μm) had higher Pb contents than the coarser YYu-1 fractions. The semi-quantitative powder X-ray diffraction analysis showed that the main Pb-containing minerals in the YYm and YYu-1 samples were galena and plumbojarosite, respectively. Tessier sequential extractions were also performed, and 1 M sodium acetate leached 21% and 65% of the Pb from the YYm and YYu-1 samples, respectively. This suggested that most of the Pb in the YYu-1 sample was ion-exchangeable and was more easily leached compared with that in the YYm sample. The findings indicate that it is important to accurately characterize the Pb-bearing minerals (especially naturally occurring Pb) present in contaminated soils before selecting appropriate remediation techniques and conditions.