Behavior and Distribution Coefficient of Some Elements in Soil under Natural Condition

在自然条件下，用超离心机采集表层土壤和土壤孔隙水中的一些元素进行了测定。测定了它们的垂直剖面和间隙水的正负离子平衡。分别估算了适用于分配系数的稳定元素（Cs、Co、Cr、Zn、Sb）的分配比。1996年，在KUR-RI的杂草地，从地表到深度约80cm处采集了未受干扰的土壤。土壤中主要离子物质（尤其是钾和硝酸盐）浓度在15cm处突然下降，表明有机质在土壤中溶解。总阳离子几乎等于总阴离子。1997年，在Maibara-cho的农田中，用岩心取样器从地表至20cm深处采集了扰动土壤（A、B、C、D）。主要离子物质浓度随深度的增加而逐渐降低，表明土壤表层有施肥作用。在点上，由于没有碱度分析，总阳离子比总阴离子大2-5倍。在B、C、D点正负离子比基本一致。计算了Cs（10^1-10^3）、Co（10^0-10^1）、Cr、Zn、Sb（10^0-10^1）的土壤交换性含量与孔溶液浓度的分布比。这些值在分布系数的范围内，在以前的工作中指出。本研究提出了评估有效非饱和分布比的实用方法。

Some elements in surface soil and soil pore water which was collected by an ultracentrifuge, under natural condition were measured. vertical profile of them and cation-anion balance of interstitial water were examined. Distribution ratios of stable elements(Cs, Co, Cr, Zn, Sb)which can be applicable to distribution coefficients respectively, were estimated.In 1996, undisturbed soil was taken from surface to the depth of about 80cm in weed land at KUR-RI.Concentrations of main ionic substances(especially potassium and nitrate)were abruptly decreased at the depth of 15cm, thus indicating dissolution of organic materials in soil. Total cation was almost equal to total anion.In 1997, disturbed soils(A,B,C,D)were taken from surface to the depth of 20cm with core sampler in cultivated field at Maibara-cho. Concentrations of main ionic substances were gradually decreased with depth, thus indicating addition of fertilizer onto soil surface. At Apoint, total cation was 2-5 times lager than total anion, owing to no analysis of alkalinity. Cation-anion ratio was almost unity at B,C,D point. Distribution ratios between exchangeable content in soil and concentration of pore solution were calculated for Cs(10^1-10^3), Co(10^0-10^1), Cr, Zn, Sb(10^0-10^1). The Values were in the range of distribution coefficients which were indicated in previous works. This research develop the useful procedure to evaluate effective unsaturated distribution ratios.