首页 | 本学科首页   官方微博 | 高级检索  
     检索      

土壤有机/无机胶体凝聚的光散射研究
引用本文:朱华玲,李航,贾明云,田锐.土壤有机/无机胶体凝聚的光散射研究[J].土壤学报,2012,49(3):409-416.
作者姓名:朱华玲  李航  贾明云  田锐
作者单位:1. 西南大学资源环境学院土壤有机无机生物界面交互作用实验室,重庆,400715
2. 中国科学院南京土壤研究所,南京,210008
基金项目:国家自然科学基金项目(面上项目,重点项目,重大项目);国家教育部博士点基金;西南大学基本科研业务费科研项目;西南大学博士基金项目
摘    要:有机/无机复合体是土壤中最重要的物质形态。本文在不同浓度的CaCl2作用下,对黄壤、胡敏酸、黄壤/胡敏酸混合胶体的凝聚动力学和凝聚体结构特征进行了研究,结果表明:黄壤、胡敏酸、黄壤/胡敏酸混合胶体的凝聚与否均强烈地依赖于体系电解质CaCl2浓度,其临界絮凝浓度(Critical flocculation con-centration,CFC)分别为1.38 mmol L-1、45 mmol L-1、15 mmol L-1。当CaCl2浓度高于CFC时,3种胶体的凝聚均表现为快速的扩散控制团簇凝聚(Diffusion limited cluster-cluster aggregation,DLCA)机制,形成分形维数分别为1.45、1.76、1.46的疏松凝聚体;当CaCl2浓度低于CFC时,3种胶体的凝聚过程对电解质浓度非常敏感,表现为慢速的反应控制团簇凝聚(Reaction limited cluster-cluster aggregation,RLCA)机制,形成分形维数高至1.58、1.86、1.56的相对紧实的凝聚体。凝聚速率越快,形成的凝聚体越疏松。在悬液中黄壤胶体自凝聚形成的结构很疏松,但是非常不稳定,而胡敏酸自凝聚体的结构非常稳定。胡敏酸的参与没有改变黄壤胶体凝聚体的结构性质,但显著促进所形成的凝聚体结构的稳定。

关 键 词:有机无机复合体  光散射  动力学  分形维数  土壤结构稳定性
收稿时间:4/6/2011 9:31:53 AM
修稿时间:2011/10/8 0:00:00

Light scattering studies of aggregation of organic/inorganic colloids in soil
Zhu Hualing,Li Hang,Jia Mingyun and Tian Rui.Light scattering studies of aggregation of organic/inorganic colloids in soil[J].Acta Pedologica Sinica,2012,49(3):409-416.
Authors:Zhu Hualing  Li Hang  Jia Mingyun and Tian Rui
Institution:1(1 Laboratory of soil Mineral-Organic-Biological Interfacial Interaction,College of Resource and Environment,Southwest University, Chongqing 400715,China)(2 Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China)
Abstract:Organic/inorganic complex is the most important form of substance in the soil. Aggregation kinetics and structural characteristics of yellow earth colloids, humic colloids and yellow earth/humic colloids were studied as affected by CaCl2 concentration. Results indicate that the aggregation of yellow earth colloids, humic colloids and yellow earth/humic colloids was strongly dependent upon concentration of the electrolyte, that is, CaCl2, with Critical Flocculation Concentration (CFC) being 1.38 mmol L-1, 15 mmol L-1 and 45 mmol L-1, respectively. When CaCl2 concentration was higher than the CFCs, aggregation of the colloids proceeded in fast diffusion-limited cluster-cluster aggregation (DLCA), thus forming loose aggregates with fractal dimension being 1.45, 1.46 and 1.76 for yellow earth colloids, humic colloids and yellow earth/humic colloids, respectively. However, when CaCl2 concentration got lower than the CFCs, aggregation of the colloids became very sensitive to the concentration of the electrolyte and displayed as slow reaction-limited cluster-cluster aggregation (RLCA), thus leading to formation of relatively compact aggregates with fractal dimension being up to 1.58, 1.56 and 1.86, separately, for the three types of colloids. Thus, the faster the aggregation velocity was, the looser the structure of aggregates would be. The findings indicate that humus contributes significantly to stability of the structure of soil mineral aggregates.
Keywords:Organic mineral complex  Light scattering  Kinetics  Fractal dimension  Soil structural stability
本文献已被 CNKI 万方数据 等数据库收录!
点击此处可从《土壤学报》浏览原始摘要信息
点击此处可从《土壤学报》下载免费的PDF全文
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号