Abstract
Selenium (Se) is an essential trace element for humans and animals. The solubility, mobility, bioavailability, and toxicity of Se are strongly controlled by its chemical speciation. Sequential chemical extraction and XAFS method were applied to study the fractionation and speciation in high-Se soils from Enshi, China, to better understand the bioavailability and other geochemistry behavior of selenium. The results showed that organic matter associated Se is the dominant fraction, and Se (IV) is the main Se speciation in most of Se-high soils from Enshi, China.
