Effects of organic matter on thallium adsorption-desorption in soils
土壤有机质对铊在土壤中吸附-解吸行为的影响

The effects of present organic matter in red soil and loess on the Tl+ adsorption-desorption behaviors were investigated. The results showed that the adsorption of Tl+ by both red soil and loess was remarkabley decreased after the removal of soil organic matter (SOM). The reduce in Tl+ adsorption capacity varied with different initial Tl+ concentrations, and the greatest degree was 24.7% and 28.2% for red soil and loess, respectively. The greatest decrease degree in Tl+ adsorption rate by loess was about 20%, which was higher than that by red soil. The contribution of SOM to the Tl+ adsorption by loess and red soil was 39.2% and 32.8%, respectively. In addition, the desorption of Tl+ from both loess and red soil was enhanced after the removal of SOM, particularly for high initial Tl+ concentration. When the initial Tl+ concentration was 20 mg/L, the desorption rate increased to 60.8% and 65.5% for red soil and loess, respectively.