Effect of NOM on colloidal stability

Scheutjens-Fleer (SF) Theory. A conceptual model for the effects of NOM on colloidal stability can be developed by using existing theoretical and experimental investigations of polymer and polyelectrolyte adsorption on solid surfaces and of the effects of macromolecules on colloidal stability. The modeling approach begins with the work of Scheutjens and Fleer for uncharged macromolecules, termed here the SF theory (3-5). This approach has been extended to the adsorption of linear flexible strong polyelectrolytes by van der Schee and Lyldema (6), adapted to weak polyelectrolytes (7-9), and applied to particle-particle interactions (8, 10). 

Figure 5. Effect of NOM on colloidal stability (a) of hematite particles. (Reproduced with permission from reference 2. Copyright 1992.)...

Effects ofNOM. Laboratory experiments by Tiller (2) on the effects of NOM on the colloidal stability of hematite particles (a-Fe203) are presented in Figure 5. Colloidal stability characterized by the sticking probability (a) is plotted as a function of the concentration of NOM (mg of C/L) added to a... 

The focus here is on the effects of dissolved natural organic matter (NOM) on the colloidal stability of particles in aquatic systems and, in particular, on the importance of the macromolecular nature of NOM in these effects. The approach used here has three components (1) modeling studies with mathematical polyelectrolytes, surfaces, and solvents (2) laboratory studies with well-characterized polyelectrolytes and particles and (3) laboratory studies with aquatic NOM, also using well-characterized particles. 

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