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Antimony (Sb) pollution is causing serious concerns in some regions globally, such as around the XiKuangShan mine in China, which is the largest Sb mine in the world. However, remediation measures are scarce. In this study, we assessed the effects of two fertilisers, sodium dihydrogen phosphate (NaH2PO4 at 200, 500 and 2000 mg kg−1) and calcium chloride (CaCl2 at 20, 80 and 200 mg kg−1), on uptake by rice (Oryza sativa L.) of Sb, cadmium (Cd) and arsenic (As) from contaminated soil under flooded conditions. Despite a very low soil As concentration (10.89 mg kg−1), the results showed that flooded conditions will result in excess accumulation of As in rice grains. NaH2PO4 generally enhanced the release of As and Sb by increasing pH and competitive adsorption in the soil, which resulted in their accumulation in many tissues of the rice plants. NaH2PO4 (200 mg kg−1) significantly reduced soil available Cd concentration by increasing soil pH, which resulted in a decrease in Cd concentration in the roots and husks. CaCl2 at 200 mg kg−1 decreased soil pH, and CaCl2 treatments increased the available Sb concentration, although not as much as NaH2PO4. Both NaH2PO4 and CaCl2 enhanced the formation of root iron plaques, and in many cases increased the concentrations of As, Cd and Sb in the root plaques, suggesting a storage role rather than a barrier of root iron plaques for plant uptake of As, Cd and Sb. CaCl2 at 200 mg kg−1 was the most effective treatment for reducing As, Sb and Cd concentrations in rice grains. We conclude that utilisation of fertilisers containing P on a soil co-contaminated by Sb and Cd poses a risk of Sb and As accumulation under continuous flooded conditions, whereas addition of CaCl2 at 200 mg kg−1 may control As, Sb and Cd accumulation in grains of rice plants under these conditions. Flooding conditions will result in excess accumulation of arsenic (As) in the grains of rice plants. NaH2PO4 generally enhanced the soil release of As and Sb by increasing pH and competitive adsorption in the soil, which resulted in their accumulation in many tissues of the rice plants. The treatment of CaCl2 at 200 mg kg−1 was most effective for reducing As, Sb and Cd concentrations in the grains. [ABSTRACT FROM AUTHOR]

Environmental context: Phytoremediation requires an understanding of bioconcentration and translocation processes that determine behaviour and fate of potentially toxic elements. We studied the distribution of antimony and arsenic in terrestrial and aquatic soil-plant systems in an antimony ore zone. We found that the common climbing plant Kudzu (Pueraria lobata) is suitable for phyto-stabilisation of antimony-bearing tailings, while tiger grass (Thysanolaena maxima) was able to extract antimony and arsenic from contaminated soils. Antimony (Sb) pollution is a major environmental issue in China. Many historical abandoned tailings have released high concentrations of Sb and its associated element arsenic (As) to surrounding environments. This has prompted the need to understand accumulation and translocation processes that determine the behaviour and fate of Sb and As in contaminated soil–plant systems and to identify suitable plant species for phytoremediation. Here we investigate distribution of Sb and As in terrestrial and aquatic dominant plant species and associated soils, all of which are naturally found in an Sb ore concentration area in south-west China. Total Sb and As concentrations were measured by inductively coupled plasma mass spectrometry (ICP-MS). The percentage of soluble Sb and As in the total concentrations were determined; the results showed that the basic soil environment facilitates the release of Sb and As from contaminated soils, and that Sb has higher mobility than As. Bioconcentration factor (BCF) and translocation factor (TF) were used for evaluating the ability of plants to accumulate and transport Sb and As, respectively. The results indicated that all selected plant species have the potential to tolerate high concentrations of Sb and As. Consequently, this study suggested that Pueraria lobata (PL) can be used as the preferred species for phytostabilisation of abandoned Sb-bearing tailings, given that PL has well-developed roots and lush leaf tissues and the ability to translocate Sb from roots to aboveground parts. Thysanolaena maxima (TM) is suitable for phyto-extraction of Sb and As in contaminated soils. Environmental context. Phytoremediation requires an understanding of bioconcentration and translocation processes that determine behaviour and fate of potentially toxic elements. We studied the distribution of antimony and arsenic in terrestrial and aquatic soil-plant systems in an antimony ore zone. We found that the common climbing plant Kudzu (Pueraria lobata) is suitable for phyto-stabilisation of antimony-bearing tailings, while tiger grass (Thysanolaena maxima) was able to extract antimony and arsenic from contaminated soils. [ABSTRACT FROM AUTHOR]