氨氮在饱水粉砂土和亚砂土层中吸附过程及其模拟

为在土地处理中选择合适保护土层厚度，防止ＮＨ４对地下水污染，通过动态土柱试验，了ＮＨ４在饱和粉砂土层和亚砂土层中的吸附和Ｃａｍｅｒｏｎ平衡＝动态吸附模型模拟了ＮＨ４在土层中的迁移过程，求得了不同土层和不同浓度条件下模型的各参数值，并求解出不同时刻，不同氨氮浓度条件下的沿程ＮＨ４浓度分布曲线。研究表明，在条件下，粉砂土和砂土的从向弥散系数分别为０．１７５和０．００９３ｃｍ＾２／ｍｉｎ；当水中氨氮浓度

Adsorption Behavior of Ammonnium Ion in Saturated Silty Sand and Sandy Loam

The adsorption characteristics of ammonium ion in saturated silty sand and sandy loam were studied by means of dynamic soil column experiments. The transportation of ammonium ion in soil were modelled with a combined equilibrium and kinetic adsorption model (Cameron's model). The coefficients (K1, K2 and K3) under different soil and NH concentration in water were obtained.The distribution curves of ammonium ion in soil were drawn. The results indicate that the longitudinal dispersion coefficients (D) in silty sand and sandy loam are 0. 175 cm2/min and 0.0093 cm2/min respectively. The dynamic adsorption capacity of silty sand are 0.156 mg/g when concentration of NH in water is 13.7 mg/L and 0. 400 mg/g when concentration of NH in water is 41. 0 mg/L; the dynamic adsorption capacity of sandy loam is 1. 33 mg/g when concentration of NH in water is 51. 0 mg/L. Above results can be used to determine the suitable thickness of protective soil in land treatment system of wastewater.