Distribution Of Antimony Species In Vegetable-planting Soils Of Chengdu And Its Affecting Factors

Antimony is of great significance in environmental and physiological study. The chemical behavior and bioavailability of antimony depend on its speciation in soil; the species of antimony in soils are controlled by general soil characteristics and other factors. However, there are few researches concerning the distribution of antimony species and its affecting factors, let alone soil zone and layer depth in vegetable-planting soils. In this paper, we focuses on antimony speciation in vegetable-planting soils of Chengdu,the contents and distribution of total antimony, antimony species as well as corresponding physico-chemical properties in each soil zone and layer were systematically investigated. Besides, the relationships between total antimony, antimony species and physico-chemical parameters were investigated and assessed by calculating Pearson correlation factors. From this paper, it was concluded as follows:(1) A low-cost and wide-linear range procedure was developed for the total antimony digestion and antimony speciation analysis with good accuracy and practicability.(2) In vegetable-planting soils of Chengdu ,the average pH value of arable layer is 6.22, the average pH value of non-arable layer is 6.25, comparing other zones ,pH values of Chenghua zone and Jingjiang zone are apparently lower; the contents of organic matter in arable layer are higher than that in non-arable layer; the range of soil cation exchange capacity (CEC) is 10.89 ~ 49.77cmol/kg; the average is 26.49cmol/kg, it is revealed that Chengdu soil has high fertility; total sulfur in arable layer and non-arable layer have significant differences in content, the content of total sulfur in arable layer is higher than that of the non-arable layer; the iron content of Fe / Mn oxides was significantly higher than manganese content.(3) The content of total antimony in Chengdu vegetable soil using AFS is1.05～8.04 mg/kg. It is concluded that vegetable-planting soils of Chengdu have not been polluted, and total antimony in arable layer and non-arable layer were significantly different.(4) In the vegetable soil of Chengdu, the distribution of antimony speciation is as follows: residual Sb > organic-bound Sb > iron-manganese oxide bound Sb > exchangeable Sb > acid rain Sb. There was a very small proportion of antimony speciation plants can be easily absorbed.(5) In both arable layer and non-arable layer of vegetable-planting soil of Chengdu, exchangeable Sb and cation exchange capacity were significantly negatively correlated , iron-manganese oxide bound Sb has a clear positive relationship with iron content. In arable layer soil, acid rain Sb has a significant positive correlation with total sulfur;in non-arable layer soil, organic-bound Sb and pH value were significantly negatively correlated but has a clear positive relationship with total sulfur.