文章基本信息

标题：Surface Activity of Humic Acids Depending on Their Origin and Humification Degree
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作者：Māris Klaviņš ; Oskars Purmalis
期刊名称：Proceedings of the Latvian Academy of Sciences, Section B. Natural, exact, and applied sciences, B dala. Dabaszinatnes
印刷版ISSN：1407-009X
电子版ISSN：1407-009X
出版年度：2014
卷号：67
期号：6
页码：493-499
DOI：10.2478/prolas-2013-0083
语种：English
出版社：The Academy
摘要：Humic substances are able to reduce the surface tension of their solutions and thus can act as surface-active substances in the natural environment, which may have industrial application. The ability to influence the surface tension of humic acid solutions depends on the origin of the humic acids. The objective of this study was comparison of the ability of humic acids of different origin (soil, water, peat, lignite etc.) to influence the surface tension of their solutions, and identification of the structural characteristics of peat humic acids that determine their surfactant properties. Industrially produced humic materials demonstrated no or insignificant impact on the surface tension of their solutions. However, humic acids isolated from peat had significant impact of the surface tension of their solutions, acting as weak surfactants. The surface tension of humic acid solutions decreased with increasing concentration, and depended on solution pH. Using a well-characterised bog profile, the ability to influence the surface tension of peat humic acids was shown to depend on age and humification degree. With increase of the humification degree and age, molecular complexity of humic acids and their ability to influence surface tension decreased; but nevertheless, the impact of the biological precursor (peat-forming bryophytes and plants) could be identified.
关键词：surface tension; humic acids; humification degree; peat