A review of non-DLVO interactions in environmental colloidal systems

The interaction and behavior of surfaces or colloids is of quantitative significance in understanding the transport and fate of compounds and microorganisms in environmental systems. Historically, the DLVO model of colloid stability has described these interactions. This model finds its basis in a force (energy) balance that comprises attractive van der Waals and repulsive electrostatic interactions. Recently, the DLVO model has been found unable to fully describe biotic and abiotic colloidal behavior in aqueous media. The suspending phase (commonly water) is often treated as a force (energy) transmitting or propagating medium. It is reasonable to believe that the structure of water may participate in a more significant fashion. Moreover, other moieties (sorbed and dissolved) may also have non-DLVO effects. Significant work has been focused on extending the precepts of the traditional DLVO model to accommodate these non-DLVO forces (energies). This paper reviews many of the interactions that play a role in environmental systems and are not commonly subsumed by the traditional DLVO model: e.g., hydrogen bonding and the hydrophobic effect, hydration pressure, non-charge transfer Lewis acid base interactions, and steric interactions. © 2002 Kluwer Academic Publishers.