Resolving the Coupled Effects of Hydrodynamics and DLVO Forces on Colloid Attachment in Porous Media

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• 作者：Saeed Torkzaban ; Scott A. Bradford ; Sharon L. Walker
• 刊名：Langmuir
• 出版年：2007
• 出版时间：September 11, 2007
• 年：2007
• 卷：23
• 期：19
• 页码：9652 - 9660
• 全文大小：204K
• 年卷期：v.23,no.19(September 11, 2007)
• ISSN：1520-5827

文摘

Transport of colloidal particles in porous media is governed by the rate at which the colloids strike and stick tocollector surfaces. Classic filtration theory has considered the influence of system hydrodynamics on determining therate at which colloids strike collector surfaces, but has neglected the influence of hydrodynamic forces in the calculationof the collision efficiency. Computational simulations based on the sphere-in-cell model were conducted that consideredthe influence of hydrodynamic and Derjaguin-Landau-Verwey-Overbeek (DLVO) forces on colloid attachmentto collectors of various shape and size. Our analysis indicated that hydrodynamic and DLVO forces and collector shapeand size significantly influenced the colloid collision efficiency. Colloid attachment was only possible on regions ofthe collector where the torque from hydrodynamic shear acting on colloids adjacent to collector surfaces was less thanthe adhesive (DLVO) torque that resists detachment. The fraction of the collector surface area on which attachmentwas possible increased with solution ionic strength, collector size, and decreasing flow velocity. Simulations demonstratedthat quantitative evaluation of colloid transport through porous media will require nontraditional approaches thataccount for hydrodynamic and DLVO forces as well as collector shape and size.