土壤不同粒径组分对菲的吸附解吸行为的研究

Sorption and Desorption of Phenanthrene by Soil Different Particle-Size Separates

有机污染物在土壤环境中的行为主要取决于它们与土壤不同组分之间的相互作用，土壤不同粒径组分中有机质的含量和结构特征以及矿物组成不同，它们对有机污染物的环境行为影响也不同。本研究用物理方法将两种不同类型土壤水稻土（SEBC-07）和红壤（SEBC-13）分成粒径大小不同的土壤组分（〈2μm、2～20μm、20～54μm、54～105μm、105～280μm、〉280μm），研究了它们对菲的吸附解吸行为。SEBC-07土样不同粒径组分对菲的吸附容量（Kf）从大到小顺序为：2～20μm、20～54μm、54～105μm、〈2μm、〉105μm：SEBC-13土样不同粒径组分的所值从大到小顺序为：20～54μm、〈2μm、2～20μm、54～105μm、105～280μm、〉280μm。除〈2μm和20-54μm的粒径组分外，有机质含量较高的水稻土不同粒径组分对菲的吸附容量都明显高于有机质含量较低的红壤。两种土壤20～54岬组分的Koc值都最大，然后向粒径增大和减小的方向都逐渐降低。不同粒径组分的坼和心。值与它们的理化性质（有机碳含量、比表面积）都没有显著的相关性。两种土壤的不同粒径组分对菲的解吸都有不同程度的滞后现象。

Fate and behavior of polycyclic aromatic hydrocarbons （PAHs） in soil environment are mainly controlled by their interactions with different soil components. Generally, the content and structure characteristics of organic matter and mineral composition in different soil particle-size separates are different. Hence, the environmental fate of organic pollutants affected by different soil particle-size separates is different. In this paper, two different type soils, paddy soil （SEBC-07） and red soil （SEBC-13） were separated into different particle-size separates （〈2 μm, 2 - 20 μm, 20 - 54 μm, 54 - 105 μm, 105 - 280 μm, 〉280 μm） by physical method, and the sorption and desorption of phenanthrene by them were studied. The rankings of the sorption capacities （Kf） of phenanthrene by different particle-size separates of SEBC-07 and SEBC-13 were 2 -20 μm 〉 20 - 54 μm 〉 54 - 105 μm 〉 〈 2 μm 〉 〈 105 μm and 20 - 54 μm 〉 〈 2 μm 〉 2-20 μm 〉 54 - 105 μm 〉 105 -280 μm 〉 〉280 μm, respectively. The sorption capacities of all the particle-size separates of the paddy soil with high organic matter content were significantly greater than those of in the red soil with low organic matter content, except 〈 2μm and 20-54 μm separates. In both soils, Koc values of 20 - 54 μm separates were greatest, and then decreased with increasing or decreasing particle-size. The values of Kf and Koc of different particle-size separates of two soils had no significant correlation with their physio-chemical properties （e.g. organic content and specific surface area）. Desorption hysteresis were observed of different particle-size separates of both soils.