Solid phase concentration, effect

The solid phase concentrations are influenced only by the rate of mass transfer, with convection and dispersion effects both being zero for this phase. 

Taking the balance, around both phases, effectively disregards the rate of solute transfer from liquid to solid and, instead, the assumption of a perfect equilibrium stage is employed to provide a relation between the resulting liquid and solid phase concentrations. For the special case of a linear equilibrium... 

Figure 4 illustrates the effect of different binding mechanisms on the porewater concentrations of metals and metalloid species in relation to the solid-phase concentrations. First, if a certain component were very soluble and not bound to the solid in any way, the pore water concentration at equilibrium would equal the total concentration in the system. However,... 

The average dimensionless solid phase concentration Y can be given409 the numerical value of 0.5, and if the effect of the film mass transfer is negligible, i.e., if K f - 00, then adsorption with the nonporous HPLC sorbent in a well-packed bed is controlled by second-order kinetics.169,399 When the external film resistance Kf controls the adsorption, equilibrium is assumed to exist between the polypeptide or protein and the polypeptide- or protein-ligate complex at each point on the particle surface. 

In the second group, the solid-phase concentration is high, and solids particles are either loose but in contact, or consolidated. In this case, the solid phase is the matrix, while the liquid phase is the dispersed phase. In this group, electrical conductivity is used to measure the effective porosity of the porous medium (64, 65). Also, if two immiscible fluids, for example, oil and water, are present in a porous medium, the electrical conductivity can be employed to measure the relative saturations of the two fluids and to give an indication of the wettability of the porous medium (66, 67). 

Fig. 8.3. The effect of washes on the dissociation of immune complexes for antibodies with different affinities and with different initial saturations (Table 8.3). The antibody (immobilized on the solid phase) concentration is 10 M (fairly typical for microtitre plates). Low affinities result in rapid dissociation and the activity measured is more representative for affinity than initial antigen concentration. With high affinities,...

Bower, C. Washington, C., Purewal, T.S. The effect of surfactant and solid phase concentration on drug aggregates in model aerosol propellents. J. Pharm. Pharma, col.. 48 342-346. 1996. 

The determination of R (see Eq. 7.25) by a measurement of the partition coefficient k in the laboratory, by some type of sorption experiment for the determination of adsorbed solid-phase concentration versus solution-phase concentration in equilibrium (so-called isopleths or isotherm), however, supplies values of R which are not comparable with the actual in field retardation factors in a mineral liner, because the specific surface susceptible to the pollutant is very different in both cases. Therefore, based on diffusion coefBcients in free aqueous solutions, the effective diffusion coefficients of organic substances for water-saturated mineral liners were estimated by using a tortuosity factor F= 1/3 (Muller et al. 1997a). Table 7.6 shows the results for various soil materials. 

In the case of the mixed kineticsthe diffusion mass transfer in the solid and liquid phases occur with comparable rates) on an ideally flat electrode with = 0 in the presence of a solid phase adsorption effect the diffusion problem (2)-(12) is reduced to the onedimensional task. Its solution is obtained using the method of the integral Laplace-Carson transformation in the form of concentration profiles and voltammogram ... 

Among the many, such combination method, which allows to combine the sorption concentration and the subsequent photometrical determination in solid phase, as solid-phase spectrophotometry (SPS), proves to be very effective in the analysis. 

These three diagrams show clearly how a very small change in the relative position of the AG-concentration curves for the different phases can have a dramatic effect on the composition and stability of the solid phases in the Fe,j,-Zn( system. A detailed discussion of these diagrams can be found elsewhere In addition, Fig. 7.86 shows that any physical effects in the solid phases, which can be expressed in terms of energy, can be added to the AG -concentration curves. Thus the curves can be corrected for these effects and the resulting new equilibria from the shift of the AG-concentra-tion curves (i.e. change in composition of phase, their stability, etc.) can be predicted simply by the use of the tangency rule. 

At a fixed temperature, what effect would adding more CaCO, have on the concentration of C02 in the region above the solid phase Explain. 

Braga et al. ° compared the efficiencies of several processes, i.e., hydrodistillation, low pressnre solvent extraction, and Soxhlet and supercritical fluid extraction. For each process, the inflnences of several parameters (duration, temperature, nature of solvent) were also evalnated. These authors concluded that the Soxhlet method performed with ethanol/isopropanol 1/100 v/v for 2 hr and 30 min was the most effective. Snn et al. nsed solid phase extraction to concentrate (nine times) a... 

Ion exchange is a reversible interchange of ions between a liquid and a solid phase. The ions (contaminants) in a liquid wastestream and the ions on the surface of an ion-exchange resin are exchanged, purifying the wastestream while concentrating the waste constituent in the resin.22 24 Mixed resins are sometimes effective in removing both cations and anions. 

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