Prediction of colloid detachment in a model porous media: Thermodynamics

✍ Scribed by John Bergendahl; Domenico Grasso

• Publisher: American Institute of Chemical Engineers
• Year: 1999
• Tongue: English
• Weight: 137 KB
• Volume: 45
• Category: Article
• ISSN: 0001-1541
• DOI: 10.1002/aic.690450305

✦ Synopsis

Detachment of polystyrene latex colloids was studied in a model porous media system comprised of a packed column of glass beads. The polystyrene colloids were attached and subsequently detached from the glass beads by ®arying solution pH and ionic strength. It was found that classical-DLVO theory could not predict detaching conditions. Extended-DLVO theory was used to determine the median detaching pH for deionized water, and solutions of 0.01 and 0.1 M NaCl. Although both the colloids and porous media were macroscopically homogeneous, detachment was obser®ed at a ®ariety of pH ®alues. The pH distribution of detachment and the energy distribution of the interaction between the polystyrene latex colloids and the glass beads followed gamma distributions. This work has pro®ided a technique to quantitati®ely predict the aqueous chemistry changes that induce colloid detachment in porous media.