摘要:
近来的研究结果显示土壤中的水溶性胶体可能对营养物质和各种污染物的迁移和转化起到关键作用。然而，目前国内外对土壤中水溶性胶体的系统研究和报道比较少。本文对中国东北肇东盐碱土壤中的水溶性胶体进行了提取和研究。使用了原子力显微镜,X射线衍射法和光电子能谱等技术对获得的水溶性胶体进行了表征。原子力显微镜观察结果显示这些水溶性胶体呈现为较大的片状固体以及粒径范围很广的球体。X射线衍射法和光电子能谱测定表明这些水溶性胶体是由高岭石，伊利石、方解石、石英石所组成。我们同时也对经过水解聚马来酸酐(HPMA)处理后的盐碱土壤中水溶性胶体以及邻近的农业土壤中水溶性胶体进行了测定和比较。测定结果揭示了盐碱环境有利于产生大量不同粒径的胶体而经过水解聚马来酸酐(HPMA)处理的盐碱土壤和农业土壤中则含有较少量的粒径较小的胶体。本研究所得到的结果可加深研究者对盐碱土壤的认识以及水解聚马来酸酐(HPMA)治理盐碱土壤的基本原理。
Abstract: Recent studies indicated that water-dispersible colloids play important roles in transportation of nutrients and contaminants in soils. However, there are few systematic studies on the water-dis- persible colloids in soil so far. In this study, the water-dispersible colloids in the saline-alkali soils in Zhaodong, northeast of China, were extracted and further characterized by Atomic force microscopy (AFM), X-ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS). AFM observation indicated that the water-dispersible colloids contain some large plates and many small spherical particles with a wide range of size distribution. XRD and XPS measurement revealed that the wa-ter-dispersible colloids are composed of kaolinite, illite, calcite, quartz and humic acid. The wa-ter-dispersible colloids extracted from the saline-alkali soils pretreated with hydrolyzed polymaleic anhydride (HPMA) and an agricultural soil were also investigated and compared. The differences of the water-dispersible colloids in the saline-alkali soils and agricultural soil implied that the saline-alkali condition facilitate the formation of the large colloids. The present study is very useful for enriching the knowledge of the saline-alkali soils and understanding the reclamation mechanism of HPMA for the saline-alkali soils.