【摘要】 持久性有机污染物在土壤环境中的行为在很大程度上取决于土壤有机质对它们的吸附作用,粒径分组通常用来区分具有不同有机质组成和周转速率的有机质库。本研究利用菲(Phe)和苯并[a]芘(Bap)作为多环芳烃(PAHs)低、高环组分的代表物质,研究了它们在污染区9个农业表层土壤(0~20 cm)不同粒径组分(粘粒、细粉粒、粗粉粒、细砂粒和粗砂粒)中的分配特征。结果表明,Phe在不同粒径组分中的平均含量大小顺序为粗砂粒>细砂粒>粘粒>细粉粒>粗粉粒,Bap为粗砂粒>细砂粒>粗粉粒>细粉粒>粘粒。Phe和Bap在不同粒径组分中的含量与粒径组分中有机质的含量均呈显著性正相关(p<0.01)。不同粒径组分中的有机质对Phe富集能力的大小顺序为粗粉粒>细粉粒>细砂粒>粗砂粒>粘粒,对Bap的富集能力为粗粉粒>粗砂粒>细粉粒>细砂粒>粘粒。更多还原

【Abstract】 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.更多还原