Abstract:
BACKGROUND It is of great significance for evaluation, early warning and remediation of antimony contaminated soil to study the sorption factors affecting Sb(Ⅲ) adsorption in soil.
OBJECTIVES To investigate the forms of Fe and Mn oxides and controlling factors of Sb(Ⅲ) adsorption in soil.
METHODS The physicochemical properties, mechanical composition, and main chemical composition of soils from 10 different areas were determined by chemical method, inductively coupled plasma-optical emission spectrometry and atomic fluorescence spectrometry. The contents of different forms of iron and manganese and the saturated adsorption capacity of soils to Sb(Ⅲ) were determined by atomic absorption spectrometry. The correlation analysis, principal component analysis and factor analysis of soil saturated adsorption capacity to Sb(Ⅲ), soil physicochemical properties, mechanical composition, iron and manganese oxides and their forms were carried out by SPSS 21.0.
RESULTS On the basis of studying the influencing factors of soil adsorption of Sb(Ⅲ), the main controlling factors were further studied. The saturated adsorption capacity of soil to Sb(Ⅲ) was between 0.63mg/g and 3.98mg/g, and was related to soil type with the order of red soil>brown soil>yellow soil>cinnamon soil>sandy soil. According to the correlation analysis results, the saturated adsorption capacity of soil to Sb(Ⅲ) was significantly positively correlated with cation exchange capacity, total iron oxide, amorphous iron content, and was positively correlated with free iron content, amorphous manganese content and free manganese content. The principal component analysis and factor analysis showed that these six factors were the main controlling factors affecting the adsorption of Sb(Ⅲ) in soil, and the influence degree was: total iron oxide>cation exchange capacity>amorphous iron content>free iron content>amorphous manganese content>free manganese content.
CONCLUSIONS The adsorption capacity of soil to Sb(Ⅲ) is significantly affected by the total amount of iron and manganese oxides and their forms.