Colloidal stability aquatic environments

More important for the purposes of this review is the possible participation of soil in promoting transformation involving extracellular DNA stabilized in some manner by its interaction with soil colloids. Extracellular DNA originates from soil bacteria (Lorenz et al., 1991) and genetically modified bacteria placed in aquatic environments (Paul David, 1989), and exists in environmental matrices (Lorenz et al., 1981 Ogram et al., 1987 Paul et al., 1990). 

Interfacial chemistry and system hydrodynamics control the aggregation, deposition, and separation of particles and particle-reactive substances in natural aquatic environments and in many technological systems. Hydrodynamics (particle transport) are particularly sensitive to particle size and size distribution colloidal stability is usually determined by the presence of macromolecular natural organic substances. Recent theoretical and experimental studies of the effects of these two classes of variables on solid-liquid separation in aquatic systems are presented and discussed. 

This three-component approach to studying the influence of NOM on colloidal stability in aquatic environments was used by Tiller (2). Some of the results presented here are adapted from this work additional information about the models and the experiments can be found in this thesis. 

Let us consider the colloidal stability of particles as ones view moves from a mountain spring to a river, through an estuaiy, and into the ocean. Solid particles and natural organic matter are everywhere in aquatic environments. Here we consider that NOM adsorbs on particles and affects their colloidal stability. We discuss the origins of this stability a long the riverrun (I). Our conclusions are based on results with both mathematical and laboratory chemicals (2). Speculation is extensive. 

There is extensive evidence from freshwaters, estuaries, and the oceans that the surface properties, colloidal stability, and the kinetics of aggregation reactions in natural waters are affected by naturally occurring organic substances dissolved in these waters. These effects of natural organic substances in establishing colloidal stability in aquatic systems are anticipated to occur in subsurface environments and to affect the kinetics of particle and pollutant passage and retention in subsurface systems. The kinetics, extent, and significance of... 

Adsorption of enteric viruses on mineral surfaces in soil and aquatic environments is well recognized as an important mechanism controlling virus dissemination in natural systems. The adsorption of poliovirus type 1, strain LSc2ab, on oxide surfaces was studied from the standpoint of equilibrium thermodynamics. Mass-action free energies are found to agree with potentials evaluated from the DLVO-Lifshitz theory of colloid stability, the sum of electrodynamic van der Waals potentials and electrostatic double-layer interactions. The effects of pH and ionic strength as well as electrokinetic and dielectric properties of system components are developed from the model in the context of virus adsorption in extra-host systems. 

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