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Analysis of partition coefficients of ternary liquid-liquid equilibrium systems and finding consistency using UNIQUAC model

Islam A. W., Zavvadi A., Kabadi V. N.

Chemical and Process Engineering

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2012

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Vol. 33, nr 2

243-253

EN

The objective of this study is to investigate the change in partition coefficient with a change in the concentration of the solute in a liquid system consisting of two relatively immiscible solvents. To investigate the changes in the partition coefficients, the data of the partition coefficients at infinite dilution and the ternary Liquid-Liquid Equilibrium (LLE) data at finite concentrations of the solute should be consistent. In this study, 29 ternary systems that are found in literature and for which the partition coefficients at infinite dilution and the ternary LLE data cannot be predicted accurately by the universal quasi-chemical (UNIQUAC) model are identified. On the basis of this model, some consistent and inconsistent ternary systems are introduced. Three inconsistent systems, namely hexane-butanol-water, CC14 (carbon tetrachloride)-PA (propanoic acid)-water, and hexane-PA-water, are chosen for detailed analysis in this study. The UNIQUAC activity coefficient model is used to represent these data over a range of concentrations. The results show large errors, exhibiting the inability of this model to correlate the data. Furthermore, some ternary systems in which cross behavior of solutes between two phases observed are identified.

2

Effect of selected parameters on the adsorption of chromium and iron ions in soil

Plaskota-Kamecka D., Dziubiński M.

Chemia i Inżynieria Ekologiczna

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2006

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Vol. 13, nr 3-4

223-230

EN

Results of analysis of chromium and iron content in soil samples taken from three types of soil: peat, soil samples from Łódź and from Kutno are discussed. In order to determine values of the partition coefficient for chromium and iron, the soil samples of the known mass were subjected to sorption using the solutions of Cr(NO3)3 . 9H2O and Fe(NO3)3 . 9H2O at the concentrations 1.0, 0.5, 0.25 and 0.125 g/dm3. Then, sorption kinetic curves were prepared on the basis of the Freundlich equation and using linear sorption isotherm the partition coefficients of the tested metals were specified. The partition coefficients allowed to detennine the influence of selected parameters, i.e. the type of ion, its initial concentration, the type of soil examined and diameter of particles that form the soil, on adsorption process in the soil.

PL

Środowisko glebowe jest jednym z głównych rezerwuarów wielu zanieczyszczeń. W pracy przedstawiono wyniki analizy zawartości chromu i żelaza w próbkach trzech rodzajów gleb: torfu oraz gleb z okolic Łodzi i Kutna. W celu opracowania wartości współczynników podziału dla chromu i żelaza wykonano badania procesu sorpcji jonów tych metali na próbkach gleby o znanej masie przy użyciu roztworów: Cr(NO3)3 . 9H2O i Fe(NO3)3 . 9H2O o stężeniach: 1,0; 0,5; 0,25; 0,125 g/dm3. Następnie na podstawie równania Freu-ndlicha oraz liniowej izotermy sorpcji sporządzono krzywe kinetyki sorpcji, a na ich podstawie wyznaczono wartości współczynników podziału dla danego metalu. Współczynnik podziału pozwolił na określenie wpływu wybranych parametrów, tj: rodzaju jonu, jego stężenia początkowego, rodzaju gleby oraz średnicy ziarna gleby na proces sorpcji wybranych jonów metali ciężkich w glebie.

3

Isothermal Gas Chromatographic Partion Coefficients of n-Alkanes, Benzene, Methylbenzenes and Chlobenzenes on Two Opposite Polarity Stationary Phases

Perez-Parajon J., Santiuste J.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 5

883-896

EN

Partition coefficients of benzene, its twelve methylbenzenes and its twelve chlorobenzenes have been estimated on two fused silica capillary columns coated with the stationary phases HP-5 and ZB-WAX at 100-180_C range. These retention data are compared to evaluate the column temperature effect, the dependence of the substituent number and the influence of the stationary phase polarity. The partition coefficient decreases with increasing column temperature in all cases, but, on the contrary, it increases with the number of methyl radicals and chlorine atoms at each stationary phase at each temperature, and it increases for the polar stationary phase. The partition coefficients of the isomers (1,2-), (1,2,3-) and (1,2,3,4-) are larger than those of the other diisomers (1,3-) and (1,4-), triisomers (1,2,4-) and (1,3,5-), and tetraisomers (1,2,3,5-) and (1,2,4,5-). Discussion in terms of physicochemical properties of these isomers is forwarded.