Sorption and desorption of copper in irrigated desert soils from oasis regions
干旱区绿洲灌漠土对铜的吸附解吸特性研究

Sorption and desorption of heavy metals is one of the primary processes that affect the destination and mobility of heavy metals in soils. Laboratory batch experiments, single extraction procedure and sequential extraction procedure were conducted to study the sorption and desorption of copper (Cu) in irrigated desert soils from the oasis regions. Cu sorption behavior could be described by Freundlich equation. Cu sorption capacity in the irrigated desert soils was likely to be controlled by the combination of soil characteristics such as texture, pH, organic matter, and CaCO3 rather than a single factor. Secondary power function can be used to simulate the relationship between Cu desorption capacity and sorption capacity before desorption in the irrigated desert soils. Cu sorption was irreversible (low exchangeable fraction) in the irrigated soils. Absorbed Cu was distributed mainly in inorganic fraction and organic fraction. In general, Cu percentage in inorganic fraction was higher than that in organic fraction at the studied Cu concentration, probably because CaCO3 content and high pH in the soils from arid regions.