Over het archief
Het OWA, het open archief van het Waterbouwkundig Laboratorium heeft tot doel alle vrij toegankelijke onderzoeksresultaten van dit instituut in digitale vorm aan te bieden. Op die manier wil het de zichtbaarheid, verspreiding en gebruik van deze onderzoeksresultaten, alsook de wetenschappelijke communicatie maximaal bevorderen.
Dit archief wordt uitgebouwd en beheerd volgens de principes van de Open Access Movement, en het daaruit ontstane Open Archives Initiative.
Basisinformatie over ‘Open Access to scholarly information'.
Competition between kaolinite flocculation and stabilization in divalent cation solutions dosed with anionic polyacrylamides
Lee, B.J.; Schlautman, M.A.; Toorman, E.; Fettweis, M. (2012). Competition between kaolinite flocculation and stabilization in divalent cation solutions dosed with anionic polyacrylamides. Wat. Res. 46(17): 5696-5706. http://dx.doi.org/10.1016/j.watres.2012.07.056
In: Water Research. Elsevier: Oxford; New York. ISSN 0043-1354; e-ISSN 1879-2448, meer
|  |
| Trefwoorden |
Colloids
Divalent cations
Polyelectrolytes
Separation > Chemical precipitation > Flocculation
Stabilization
Marien/Kust |
| Author keywords |
|
| Auteurs | | Top |
- Lee, B.J., meer
- Schlautman, M.A.
- Toorman, E., meer
- Fettweis, M., meer
|
|
|
| Abstract |
Divalent cations have been reported to develop bridges between anionic polyelectrolytes and negatively-charged colloidal particles, thereby enhancing particle flocculation. However, results from this study of kaolinite suspensions dosed with various anionic polyacrylamides (PAMs) reveal that Ca2+ and Mg2+ can lead to colloid stabilization under some conditions. To explain the opposite but coexisting processes of flocculation and stabilization with divalent cations, a conceptual flocculation model with (1) particle-binding divalent cationic bridges between PAM molecules and kaolinite particles and (2) polymer-binding divalent cationic bridges between PAM molecules is proposed. The particle-binding bridges enhanced flocculation and aggregated kaolinite particles in large, easily-settleable flocs whereas the polymer-binding bridges increased steric stabilization by developing polymer layers covering the kaolinite surface. Both the particle-binding and polymer-binding divalent cationic bridges coexist in anionic PAM- and kaolinite-containing suspensions and thus induce the counteracting processes of particle flocculation and stabilization. Therefore, anionic polyelectrolytes in divalent cation-enriched aqueous solutions can sometimes lead to the stabilization of colloidal particles due to the polymer-binding divalent cationic bridges. |
IMIS is ontwikkeld en wordt gehost door het VLIZ.
