Selenium (Se) nanotechnology has been applied for different applications in different fields, such as agriculture, medical science, and electronic industries, and Se nanomaterials have become one of the emerging contaminants of concern in recent years. Therefore, potential environmental impacts of Se nanomaterials need to be appropriately addressed. Currently, few studies have been carried out to determine the transport and fate of elemental Se nanoparticles (SeNPs) in the soil environment. This laboratory study characterized chemically synthesized elemental SeNPs with a diameter of 17-69 nm, and evaluated the stability and partitioning of elemental SeNPs among different fractions in the soils containing different levels of soil organic matter. The fractionation and speciation analysis of Se in the soil treated with different levels of elemental SeNPs indicated that the bioavailable Se in water soluble and exchangeable fractions tended to be transformed into more stable Se in the organic matter (OM)-bound and residual fractions during the soil incubation process. The results from this study suggest that increasing the soil incubation time will increase the size of SeNPs, and aggregated SeNPs might potentially decrease the environmental risk of SeNPs in the soil environment. Chemical behaviors of SeNPs in the soil were also affected by the contents of soil organic matter through adsorption and aggregation processes. Less Se from SeNPs was found in the exchangeable fraction when soil incubation time increased. Nanoscale elemental Se showed different chemical behaviors in comparison to selenate in the soil. Concentrations of water soluble Se in the SeNP treatment were significantly (p<0.05) lower than the Se concentrations in the selenate treatment in the soil with low organic matter, but higher than the concentrations in the selenate treatment in the soil with high organic matter after incubation for 7 days. Selenium speciation analysis using HPLC-ICP/MS suggested that, in the soil treated with SeNPs, nanoscale elemental Se was transformed into other chemical forms e.g. selenite and selenate during the soil incubation process.
|Commitee:||Theodorakis, Christopher W., Yoon, Kyong Sup|
|School:||Southern Illinois University at Edwardsville|
|School Location:||United States -- Illinois|
|Source:||MAI 55/05M(E), Masters Abstracts International|
|Subjects:||Soil sciences, Aging, Nanoscience|
|Keywords:||Nanoparticles, Selenium, Soil|
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