Mobility and phytoavailability of antimony in an area impacted by a former stibnite mine exploitation

Abstract

A mining area affected by the abandoned mine exploitation of a stibnite deposit was studied to establish the current and eventual environmental risks and to propose possible remediation practices. Soil and plant samples were collected at different places in this area and analyzed for their Sb content and distribution. Critical soil total concentrations of Sb were found, with values ranging from 585 to 3184 mg kg(-1) dry weight in the uppermost soil layer, and decreasing progressively with soil depth. The readily labile Sb contents represent <2% of the total concentrations, whereas the soil Sb contents more susceptible of being mobilized under changing environmental conditions attain values of about 4-9% of the total concentrations. Remediation measures should be undertaken to limit off-site migration of Sb. Within the tolerant plant community growing in this area, the shrub Daphne gnidium L. stands out for its relatively high root Sb accumulation and low Sb translocation, suggesting its feasibility to be used in Sb phytostabilization strategies.