滤纸法测定非饱和土壤离子吸附等温线的初步研究

滤纸法对非饱和土壤溶液离子浓度的变化有较高的敏感性和较好的重现性 ,能够用于非饱和土壤离子吸附等温线的测定。滤纸法和乙醇浸提法、离心法有很好的一致性。滤纸法测定的非饱和土壤NH 4 、K 离子吸附等温线具有一般吸附等温线的共性 ,可用Freundlich方程描述 ,且达极显著相关水平。在土壤溶液浓度相同的情况下 ,液土比增大 ,离子固相吸附量增大 ,Freundlich方程的k值 ,n值增大 ,说明液土比增大有利于非饱和土壤离子吸附反应进行

DETERMINATION OF ION ADSORPTION ISOTHERMS OF UNSATURATED SOIL WITH FILTER PAPER METHOD

The filter paper method discussed in this paper shows good sensitivity and reproducibility to unsaturated soil solution concentration changes, so it can be used to obtain ion adsorption isotherms in unsaturated soils. It is also quite concordance with the centrifugal method and the ethyl alcohol extracting method. NH 4?K adsorption isotherms in unsaturated soil obtained with the filter paper method possess ordinary characteristics of ion adsorption isotherms, and can be significantly fitted by Freundlich equation. With a certain equilibrium concentration, the adsorbed amount in solid phase and fitted parameters ( k, n ) of Freundlich equation increase with increasing solution/soil ratio, indicating that increasing solution/soil ratio can promote ion adsorption reaction in unsaturated soil.;