Effects of the amendment on the heavy metal forms of antimony and bioavailability in Chinese antimony mining

The experiment of artificial afforestation combining with soil amendment was carried out to investigate the effects of soil amendment on antimony (Sb) chemical forms, and its bioavailability in Chinese antimony mining. This research provides the technical basis for ecological remediation of Sb contaminated soils. The results showed that the soil pH values increased with the increasing of discharging amount of soil amendment. While using 300 g soil amendment on each plant, the soil pH value changed from acidic to alkaline. Soil amendment had significant effect in 0-20 and 40-60 cm soil layers on carbonate-bound Sb and had very significant effect in 20-40 cm soil layer, and very significant effect on residual form in 40-60 cm. The FeMn oxideand organic-bound and residual forms mainly exist in 0-20 cm and 20-40 cm depth of soils in antimony mining. However, organicand FeMn oxide-bound Sb exist in 40-60 cm depth of soil. The amendment addition increased Sb bioavailability by 18.92-24.23%, and decreased Sb potential bioavailability and Sb non-bioavailability by 17.55-18.92% and 0.95-6.03%, respectively.