三江平原小叶章湿地土壤SO_4^(2-)的吸附与解吸特征

Sulfate Adsorption and Desorption Characteristics of Calamagrostis angustifolia Wetland Soil in Sanjiang Plain

以三江平原小叶章湿地为研究对象,研究了小叶章湿地土壤SO42-的吸附和解吸特征。结果表明,小叶章湿地不同层土壤对SO42-的等温吸附均可以用Langmuir、Freundrich和Temkin方程来表示,且吸附能力均随土壤深度的增加而增加,这种变化和土壤有机质、pH值和粘粒含量密切相关。土壤的解吸能力不仅和土壤质地密切相关,而且受土壤中吸附SO42-的影响,一般当土壤中吸附SO42-量较大时,解吸的绝对量大,但解吸率较低,反之亦然。吸附率明显高于解吸率,对于延缓土壤的酸化具有一定的意义。

The characteristics of sulfate adsorption and desorption were studied by choosing Calamagros tis angustifolia wetland in Sanjiang Plain as the research object. The results showed that the isotherms adsorption of different layer soil to sulfate could be expressed by Freundrich, Langmuir and Temkin equations. The adsorption ability increased with the increasing of soil depth, which was closely correlated with the content of soil clay, organic matter and pH value. The desorption ability was closely correlated with not only the soil texture, but also the SO4^2- in soil. Generally speaking,when the amount of adsorbed SO4^2- in soil was much, the absolute amount of desorption was much too, but the desorption rate was low, vice versa. The adsorption ability in wetland soil was obviously higher than the desorption ability, which could delay the soil acidification.