Natural attenuation of antimony and arsenic in soils at the abandoned Sb-deposit Poproč, Slovakia

Autor: Juraj Majzlan, Štefan Méres, Tomáš Klimko, Bronislava Voleková-Lalinská, Edgar Hiller, Ralph Steininger, Jörg Göttlicher, Ľubomír Jurkovič
Rok vydání: 2019
Předmět:
Zdroj: Environmental Earth Sciences. 78
ISSN: 1866-6299
1866-6280
Popis: This contribution investigates the natural attenuation of arsenic (As) and antimony (Sb) in highly contaminated soils at the abandoned Sb-deposit Poproc in eastern Slovakia. The studied soils were identified as technosols with pH values of 3.5–7.0 and high metal and metalloid load: antimony, arsenic, lead, and zinc up to 5757, 2484, 683, and 407 mg/kg, respectively. These toxic elements occur in the soils mainly as constituents of secondary minerals, which are products of sulphide oxidation. Bulk correlation between Fe and As is weak (p > 0.05), but inspection of micro-X-ray fluorescence maps shows that the secondary iron oxides are always associated with elevated As. Electron microprobe (EMP) and micro-X-ray diffraction analyses showed significant chemical and mineralogical heterogeneity of the secondary minerals, with wide variations of their Fe/Sb ratio and occasionally elevated Ca and Pb (> 5 wt%). The most common secondary minerals are goethite (α-FeOOH) with concentrations of Sb up to 3.14 wt% and As (1.29 wt%) and tripuhyite (FeSbO4) with increased content of As (1.14 wt%). Sb-rich secondary phases were identified as valentinite/senarmontite (Sb2O3), cervantite (Sb2O4), and a pyrochlore-group mineral stibiconite. High Sb phases with increased concentrations of Ca (up to 6.48 wt%) or Pb (20.78 wt%) were identified as stibiconite (EMP). This study shows that the secondary mineralogy in naturally attenuated contaminated soils and in Sb-containing tailings is identical. Hence, such tailings achieve their final state with respect to the Sb minerals within decades and are unlikely to change further.
Databáze: OpenAIRE
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