Solubility, toxicity and sorption of antimony from smelter release

Abstract

Antimony (Sb) occurs in the environment both naturally and anthropogenically. Numerous activities cause its anthropogenic accumulation and the release is mainly into the terrestrial environment. Therefore, it is crucial to investigate the fate of Sb in soils at the smelting sites where its deposition is often very high and the land needs to be cleaned up. However, little is known regarding the sorption behavior of environmentally found Sb oxidized states in the soils with different characteristics and compositions. The present study examined solubility and toxicity of Sb from the soils polluted due to the smelting operations. An inhibition of seed growth was used as an indicator of the toxic effect of Sb. Batch adsorption experiments were conducted over the pH range of 3–7 and in different equilibrium concentrations of Sb (III) as a form of the smelter release. The water soluble proportion of Sb was low (0.70–1.63%) compared to its deposition in the surface soils; however, extracted amounts caused a slightly reduced germination rate of wheat seeds with a lighter weight. Nevertheless, the soil soluble Sb concentration did not produce severe toxicity symptoms in the growth of roots and sprouts of the germinated seeds. The effects of Sb (III) and (V) forms were slightly different at the level of 5mg·L−1. In Sb (III) solution the smaller elongation of both sprouts and roots was observed as compared to the control samples while in Sb (V) solution only sprout lengths were shorter. Distribution coefficient (Kd) of Sb in soil water system was estimated to be 56mL·g−1 at pH values of 3 and 10–17mL·g−1 at pH of 6–7. Thus, neutral pH increases Sb mobility and its translocation to the plants that should be accounted of in agricultural production and remediation activities.