Electroosmotic flow factors affecting

The velocity of the electroosmotic flow can be affected by altering the properties of the buffer system or by changing the applied voltage. The factors involved are... 

As pointed out in the previous section of this chapter, attention should be paid to electromigration rather than electroosmosis to establish the removal mechanisms of mixed heavy metals. However, high concentrations of multiple metal contaminants, especially divalent cations, can affect the electroosmotic flow in electrokinetic remediation, which is a factor that should be taken into consideration with regard to the removal mechanisms of mixed heavy metals. The electroosmotic velocity, V, is given by the Helmholtz-Smoluchowski equation (Acar and Alshawabkeh, 1993 Mitchell, 1993) ... 

In order to insure the sufficient efficiency of electrokinetic removal of multiple heavy metals from porous media, it is essential to understand the main parameters affecting the transport and electrokinetic phenomena. Such parameters can be summarized as (a) the theoretical ionic mobility related to the ionic valance and molecular diffusion coefficient of species, (b) the delaying or retardation effect caused by the affinity of heavy metals in solid matrix, and (c) the chemical forms of metal contaminants initially existing in soils. In addition, some unexpected effects especially brought about in the electrokinetic remediation of mixed metal contaminants should be considered. The electrokinetic remediation for mixed metal contaminants generally shows lower removal efficiency than that for individual metal contaminants. High concentrations of multiple metal contaminants can be related to other parameters, for example, transference number, zeta potential, electroosmotic flow, and so on, which are factors that should be taken into consideration with regard to the removal mechanisms. 

Consider two somewhat similar ionic species (e.g. dansyl amino acids, for example serine (1) and alanine (2)) to be separated using capillary electrophoresis. Deliberate on the factors that may lead to increased resolution if C i M2) is small. Comment on the role of the electroosmotic flow in increasing the resolution and affecting the retention time. 

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