Changes in Sb speciation with waterlogging of shooting range soils and impacts on plant uptake

A pot experiment was conducted to investigate the solubility and redox species of antimony (Sb) in a relocated shooting range soil and its uptake by Lolium perenne L. and Holcus lanatus L. under different water regimes. After 1-week waterlogging, the total Sb concentration in soil solution decreased from ∼110 μg L−1 to <20 μg L−1, and slowly increased over the following 4 weeks, with the dissolution of Fe and Mn (hydr)oxides. In this process, half of the Sb in soil solution was reduced to Sb(III), which greatly affected the plant uptake of Sb. Waterlogging increased shoot Sb concentrations of L. perenne by ∼10 fold but decreased uptake in H. lanatus by 80%. Results indicate that Sb might primarily be taken up as Sb(III) by L. perenne and as Sb(V) by H. lanatus. Temporary waterlogging of soil may increase the risk of trace elements entering the food chain.

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► Waterlogging increased environmental risks for contaminated shooting range soil.
► The Sb uptake by plants was dependent on redox species of Sb.
► Both water content and plant roots affect the redox potential of soil.
► Fe/Mn hydr(oxide)s play essential roles in mobilizing or immobilizing trace elements in soil.