Crucial role of iron plaque on thallium uptake by rice plant

摘要

Abstract Iron plaque is a Fe-containing oxide film produced by the?oxidation of Fe(II) in the rice root system under?the combined action of oxygen infiltration and other microorganisms. Owing to its special surface structure and physio-chemical properties, the iron plaque has a strong absorption capacity for a variety of heavy metal ions. This study aimed to first investigate the?effects of Fe species on the?geochemical fractionation of Tl in typical paddy soil systems affected by industrial activities, followed by?pot culture experiments to probe the?effects of Fe species on the?uptake and translocation of Tl in rice plants. The results of field work preliminarily showed that iron at different valences affected the conversion of the?Tl geochemical fraction in the soil. Oxidizable Tl exerted significant positive correlation relationships with Fe2+ and negative correlation relationships with Fe3+, while reducible Tl only displayed a positive correlation with Fe3+. Further analysis by pot culture experiments revealed that the contents of Fe were significantly positively correlated with Tl contents in Fe plaque (R2?=?0.529). In contrast, the water-soluble Tl contents in the soil were significantly negatively correlated with the contents of Fe (R2?=?–?0. 90, p?