SOME CHEMICAL ASPECTS OF AQUASOL DEPOSITION IN POROUS MEDIA

The transport, fate, and environmental impacts of aquasols in porous media depend in large part on the characteristics of the interfacial regions that exist between aquasol and aquifer particles and their surrounding bulk aquatic environment. Surface and solute speciation and concentration, particle size, the Hamaker constant/function of the aquasol system, and soluble natural organic matter/polyelectrolytes are particularly influential in determining the properties of this interfacial region and, in turn, aquasol stability and particle deposition and entrainment. Simulated and experimental results are presented that support the hypothesis that aquasol aggregation and deposition are reversible processes in many and perhaps most aquatic environments. Factors that contribute to this chemical reversibility are assessed.