Functions of soil constituents on the colloidal stability of volcanic ash soils
2002
"Kitahara, H. (Ibaraki Univ., Mito (Japan)) | Karube, J. "
"The colloidal stability of volcanic ash soils pretreated in different ways was investigated in relation to pH, and the functions of imogolite, soil organic matter, iron, and aluminum were discussed. Fresh topsoil coagulated in acidic conditions, and dispersed in neutral and alkaline conditions. While volcanic ash soil bears positive charge in acidic conditions and negative charge in alkaline conditions, the organic matter in soil bears negative charge in natural soil pH. In the field, volcanic ash topsoil with high organic matter content, therefore, tends to coagulate in acidic conditions and disperse in alkaline conditions. H2O2-treated soils dispersed in acidic conditions and coagulated in alkaline conditions. They dispersed near the point of zero charge, and coagulated at higher pH even though the negative charge increased with pH. As a result, we concluded that complex functions of imogolite, iron, and aluminum cause the coagulation of H2O2-treated volcanic ash soil in alkaline conditions."
Показать больше [+] Меньше [-]