Spatial Distribution of Nanosilver and Its Reactivity In Soils: a X-Ray Microprobe Study.

While a large increase in the commercial and home usage of silver nanoparticle (AgNP) products and technologies is expected in the future, few studies contribute to the risk assessment of AgNPs in terrestrial environments. Toxicity of AgNPs to soil bacteria is dependent on the physicochemical properties of the AgNPs, such as size, surface coating, and degree of surface oxidation. These properties have been well characterized by many research groups in pure culture systems. We aim to take this knowledge and apply it to soil-water systems, where AgNPs may reside after travelling through municipal wastewater treatment plants. While it is known that ionic silver prefers to bind to organic matter within the soil, the spatial variability of AgNPs has not been well studied. We examine spatial variability with in the soil matrix using synchrotron-based X-ray microprobe analysis.