Dynamic Light Scattering Study on the Aggregation Kinetics of Soil Colloidal Particles in Different Electrolyte Systems
Dynamic Light Scattering Study on the Aggregation Kinetics of Soil Colloidal Particles in Different Electrolyte Systems
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DOI：
10.3866/pku.whxb20090631
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发表时间：
2009
影响因子：
10.9
通讯作者：
Zhu Hua-ling;L. Bing;Xiong Hai-ling;Li Hang;Jia Mingyun
中科院分区：
文献类型：
--
作者：
Zhu Hua-ling;L. Bing;Xiong Hai-ling;Li Hang;Jia Mingyun
Soil colloidal aggregation kinetics was studied at different concentrations of KNO3 and Mg(NO3)2 by dynamic light scattering. By analyzing the change in light intensity and effective diameter of aggregates with time, we conclude that: (1) The stability of the light intensity in an aggregation process is a basis for judging if the collision is dominated either by Brownforce or gravity; (2) With different electrolyte systems, soil colloidal aggregation exhibits a fast diffusion鄄limited cluster aggregation (DLCA) character or various slow reaction limited cluster aggregation (RLCA) characters and a gravity sensing electrolyte concentration exists in RLCA; (3) The aggregation characters induced by two electrolytes are essentially similar but the aggregating process is more sensitive to the Mg (NO3)2 electrolyte concentration change than to KNO3. By analyzing the change of average aggregation velocity with electrolyte concentration, the turning point where electrolyte concentration changes from slow to fast aggregation is designated as the critical flocculation concentration (CFC). A new method for measuring the CFC experimentally is thus provided.