长江三角洲地区土壤环境质量与修复研究III．农业土壤不同粒径组分中菲和苯并[a]芘的分配特征
摘要
The behavior of persistent organic pollutants in soil environment largely depends on their adsorption to soil organic matter. Particle-size fractionation is usually used to differentiate organic matter pools with different composition and turnover rates. In this research, phenanthrene (Phe) and benzo [a] pyrene (Bap) were used as representatives of low-and high-ring polycyclic aromatic hydrocarbons (PAHs), respectively. The distribution characteristics of them in different particle-size separates (clay, fine silt, coarse silt, fine sand and coarse sand) of nine agricultural topsoils (0~20 cm) from a contaminated district were studied. The results showed that the average contents of Phe in different particle-size separates decreased in the order coarse sand ＞ fine sand ＞ clay ＞ fine silt ＞ coarse silt, and those of Bap in the order coarse sand ＞ fine sand ＞ coarse silt ＞ fine silt ＞ clay. In the different particle-size separates, the contents of both Phe and Bap had significantly positive correlations with that of organic matter (p＜0.01). The enrichment ability of organic matter for Phe in different particle-size separates decreased in the order coarse silt ＞ fine silt ＞ fine sand ＞ coarse sand ＞ clay, and for Bap in the order coarse silt ＞ coarse sand ＞ fine silt ＞ fine sand ＞ clay.