不同种类胶体在含水介质中沉积和释放特征

Deposition and release of different types of colloids in water-bearing media

在进行粘土、高岭土和蒙脱石三种胶体在含水介质中沉积和释放试验的基础上,重点研究不同种类胶体在含水介质中迁移、沉积和释放的差异性,同时探讨了胶体的迁移-沉积机理。结果表明,相对于粘土胶体和蒙脱石胶体,高岭土胶体最不容易在含水介质中迁移。胶体开始释放浓度随孔隙体积数的增大迅速降低,随后变化缓慢,最后趋于稳定。粘土、蒙脱石和高岭土三种胶体的总沉积率分别为28.91%、30.94%和56.13%,释放总量分别占总沉积量的41.14%、26.88%和77.53%,表明沉积在含水介质固体颗粒表面的胶体不容易完全释放出来。胶体本身的结构组成与表面化学特征的差异和空间排斥效应很好地揭示了胶体不同的迁移-沉积特征。

The self-designed column experiments are conducted to elucidate the deposition and release of the clay colloid,Kaolinite colloid and Montmorillonite colloid.The difference and mechanism of deposition and release of colloids in the water-bearing media are discussed emphatically.The results show that Kaolinite colloid,compared with clay colloid and Montmorillonite colloid,is the one most difficult to travel in the column.With the increasing of pore volumes,the release concentration of colloids decreases rapidly at the beginning of the experiment,and then changes slowly until to stable in the end.The total deposition ratio of clay colloid,Montmorillonite colloid and Kaolin colloid are 28.91%,30.94% and 56.13%.The ratio between the total releasing capacity and the deposition capacity of clay colloid,Montmorillonite colloid and Kaolin colloid are 41.14%,26.88% and 7.53% respectively,which demonstrates that the colloids deposited on the surface of solid particle are difficult to release completely in the water-bearing media.The surface chemical characteristics and structure composition of colloids,and the size exclusion effects between mobile colloidal particles and small pores within the sand medium could well revealed the difference and mechanism of transport-deposition of colloids in the water-bearing media.