Solute distribution coefficient

Sodium trimetaphosphate was used as an eluting agent for the removal of heavy metals such as Pb, Cd, Co, Cu, Fe, Ni, Zn and Cr from aqueous solutions. Distribution coefficients of these elements have been determined regarding five different concentrations of sodium trimeta phosphate (3T0 M 5T0 M 0.01 M 0.05 M 0.1 M) on this resin. By considering these distribution coefficients, the separation of heavy metals has been performed using a concentration gradient of 3T0 - 5T0 M sodium trimetaphosphate. Qualitative and quantitative determinations were realized by ICP-AES. 

Consequently, the solutes will pass through the chromatographic system at speeds that are inversely proportional to their distribution coefficients with respect to the stationary phase. The control of solute retention by the magnitude of the solute distribution coefficient will be discussed in the next chapter. 

Application of Eq. (15.1) to the liquid membrane process highlights one of the main advantages of the process, i.e., the high solute distribution coefficient that can be obtained between phases 3 and 1. However, another factor that must be considered when evaluating a separation process performance is the kinetics of transfer, which is given in a general form by Eq. (15.4). This equation indicates that the transfer rate in the contactor increases with both the interfacial flux and the specific interfacial area. 

Mark-Houwink-Sakurada constant Mass transfer coefficient around gel Fractional reduction in diffusivity within gel pores resulting from frictional effects Solute distribution coefficient Solvent viscosity nth central moment Peak skewness nth leading moment Viscosity average molecular weight Number of theoretical plates Dimensionless number... 

Results obtained in the above study indicated that the solute distribution coefficients could be varied as a function of carrier gas pressure in a rather dramatic fashion and that... 

Ds is the diffusivity of the solute in the membrane Cj is the solute concentration in the reject side ks is the solute distribution coefficient C2 is the solute concentration in the permeate side... 

Explain the term distribution coefficient (or partition ratio) for a solute distributed between two nearly immiscible liquids. Given feed-stream flow rates and compositions for a liquid extraction process and either solute distribution coefficient data or a triangular phase diagram, calculate the product stream flow rates and compositions. 

Yoshida S., Muramatsu Y., and Uchida S. (1998) Soil-solution distribution coefficients, Kds of I and IO3 for 68 Japanese soils. Radiochim. Acta 82, 293 -297. 

However, the assumption of the steady-state mass transfer through the bulk membrane phase, has been made by some authors [43,61], is oversimplified in many cases, and the assumption of equality of solute distribution coefficients of extraction and back extraction [18,46], is incorrect for most separation systems. 

Cellular freezing of natural waters implies a much larger interstitial solute incorporation in form of liquid brine than planar freezing. The planar-cellular transition may therefore be identified as a change to a milky ice appearance or by a sharp increase in the effective solute distribution coefficient Systematic observations of the... 

Strzelbicki et al. [82] showed that chromium(VI) extraction rate decreases sharply after a pH value of 6.0. In case of phenol extraction, Wan et al. [11] observed that low values of pH favored extraction as the undissociated form of phenol which is the only form soluble in oil is predominant only at pH < 4.0. Liu and Zhang [83] showed that the extraction rate of Samarium (Sm ) in low pH range is inversely proportional to the H+ concentration. Sahoo and Dutta [45] noted that the solute distribution coefficient for cephalexin extraction increased with increase in pH up to a pH value of 9.5 beyond which the distribution coefficient appears to decrease marginally. Chakraborty et al. [76] found similar result for extraction of chromium (see Fig. 4.11). 

In order to understand the thermodynamic considerations of the separation process, we need to look at the basic equations which describe the retention of a solute and relate the parameters of retention time, retention volume, and capacity factor to the thermodynamic solute distribution coefficient. 

For the extraction of many organic species, it is observed that solvents that yield higher distribution coefficients also yield lower selectivilies. In addition, it is observed frequently lhai as the solvent loading is increased (e.g., due to higher eolute concentrations in the raffinate phase), the solvent selectivity decreases. Furthermore, the addition of inextra Liable species Dm into a feed mixture may increase built the solute distribution coefficient and the solvant selectivity Hence,... 

Da solute distribution coefficient (weight fraction of solute in the solvent divided by the solute weight fraction in the raffinate phase)... 

Because of the high acidity and high sulfate and phosphate content of sulfuric acid monazite leach solutions, distribution coefficients with primary and secondary amines are lower than in Table 6.18. In monazite sulfate solutions, thorium distribution coefficients with the primary amines of Table 6.18 are still greater than 500, however. The coefficient with di(tridecyl)amine is 4.6. These are still high enough for practical processes [C5]. 

Bromine Concentratioi ip Carbon Disulfide (mol Br2/L of solution Distribution Coefficient f mol Br2/L of aqueous phase V mol Br2/L of organic phase, )... 

The surface-to-solution distribution coefficient b for the composition R"R is 6.25TO 1/mol, i.e., approximately 300 times higher than the constants and in the individual... 

Assuming conditions of infinite dilution during retention in SFC, the solute distribution coefficient can be related to the free energy of transfer by. 

The thermodynamic relationship between the solute distribution coefficient and temperature is. 

The two basic parameters that must be estimated for design work are the solute distribution coefficient and the solvent selectivity. At equilibrium, the activity of each component in the B phase Is equal to its activity in the C phase that is. 

An additional requirement for the liquid-liquid system in Fig. 7.8-5 is that the solute distribution coefficient must increase with temperature. Since, from the van t Hoff relationship,... 

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