Trophos
Higher trophic levels in the Southern North Sea
home login contact pictures
 
home objectives results background activities databases partners
TROPHOS Metadata Database
List all

By choosing an item from the pick list, you can list all the projects, persons, institutes, conferences, literature and datasets in the database.
More items, e.g. 'cruises', 'samples' will be available soon.

  
[ meld een fout in dit record ]mandje (0): toevoegen | toon Print deze pagina
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
Peer reviewed article  
Beschikbaar in  Auteurs 
Trefwoorden
    Colloids
    Divalent cations
    Polyelectrolytes
    Separation > Chemical precipitation > Flocculation
    Stabilization
    Marien/Kust
Author keywords
    Cationic bridge
Auteurs  Top 
  • Lee, B.J.
  • Schlautman, M.A.
  • Toorman, E.
  • Fettweis, M.
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.
Alle informatie in het Integrated Marine Information System (IMIS) valt onder het VLIZ Privacy beleid Top | Auteurs