scholarly journals Solubility of Rare Earth Chlorides in Ternary Water-Salt Systems in the Presence of a Fullerenol—C60(OH)24 Nanoclusters at 25 °C. Models of Nonelectrolyte Solubility in Electrolyte Solutions

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 349
Author(s):  
Nikolay A. Charykov ◽  
Viktor A. Keskinov ◽  
Kirill A. Tsvetkov ◽  
Ayat Kanbar ◽  
Konstantin N. Semenov ◽  
...  
Keyword(s):  
Rare Earth ◽  
Pure Water ◽  
Pitzer Model ◽  
Ternary Systems ◽  
Electrolyte Solutions ◽  
Water Soluble ◽  
Salting Out ◽  
Isothermal Saturation ◽  
Water Salt ◽  
Salt Systems

The solubility in triple water-salt systems containing NdCl3, PrCl3, YCl3, TbCl3 chlorides, and water-soluble fullerenol C60(OH)24 at 25 °C was studied by isothermal saturation in ampoules. The analysis for the content of rare earth elements was carried out by atomic absorption spectroscopy, for the content of fullerenol—by electronic spectrophotometry. The solubility diagrams in all four ternary systems are simple eutonic, both consisting of two branches, corresponding to the crystallization of fullerenol crystal-hydrate and rare earth chloride crystal-hydrates, and containing one nonvariant point corresponding to the saturation of both solid phases. On the long branches of C60(OH)24*18H2O crystallization, a C60(OH)24 decreases by more than 2 orders of magnitude compared to the solubility of fullerenol in pure water (salting-out effect). On very short branches of crystallization of NdCl3*6H2O, PrCl3*7H2O, YCl3*6H2O, and TbCl3*6H2O, the salting-in effect is clearly observed, and the solubility of all four chlorides increases markedly. The four diagrams cannot be correctly approximated by the simple one-term Sechenov equation (SE-1), and very accurately approximated by the three-term modified Sechenov equation (SEM-3). Both equations for the calculation of nonelectrolyte solubility in electrolyte solutions (SE-1 and SEM-3 models) are obtained, using Pitzer model of virial decomposition of excess Gibbs energy of electrolyte solution. It is shown that semi-empirical equations of SE-1 and SEM-3 models may be extended to the systems with crystallization of crystal-solvates.

Liquid-Liquid-Solid Equillibrium of Water + 2-propanol + Kosmotropic Salts: Construction of Phase Diagrams and Understanding of Salting-out Effects Using Volumetric and Compressibility Studies

2019 ◽  
Vol 9 (1) ◽  
pp. 36-49
Author(s):  
Vidhya Jadhav ◽  
Shubhangi Mane-Gavade ◽  
Rajendra Kumbhar ◽  
Sanjay Kolekar ◽  
Bhaskar Tamhankar ◽  
...  
Keyword(s):  
Sound Velocity ◽  
Phase Diagrams ◽  
Molecular Interactions ◽  
Ternary Phase ◽  
Ternary Systems ◽  
Bond Breaking ◽  
Salting Out ◽  
Ternary Phase Diagrams ◽  
Water Salt ◽  
Water Alcohol

Background: Triangular phase diagrams are important to understand the phase behaviors in ternary systems. The salting out of alcohol from water by kosmotropic salt has long been known, but the molecular interactions and the mechanism of bond breaking and making processes has not yet been fully understood. Objective: To understand the salting-out of 2-propanol from water using kosmotropic salts (Na2S2O3, Na2SO4 and Na2SO3). To study the phase equilibria of liquid-liquid, liquid-solid and liquid-liquid-solid system by constructing ternary phase diagrams. To determine the solute-solute, solute-solvent, and solvent-solvent molecular interactions to resolve the salting- out effect. Methods: The solubility data of Na2S2O3/Na2SO4/Na2SO3 salts have been reported in pure water, 2-propanol and water + 2-propanol mixtures in different concentrations at 298.15 ± 1 K. The ternary phase diagrams have been constructed from the obtained solubility data. The volumetric and acoustic data of binary and ternary systems of water + 2-propanol, water + salt and water + 2-propanol + salt has been determined using density meter and interferometer. Results: The ternary phase diagrams have been constructed for water+2-propanol+ Na2S2O3/Na2SO4/Na2SO3 system. The rise in sound velocity signifies more structural interactions in binary water-alcohol and water-salt systems, while the relation is rather change with the ternary system, as the water-alcohol sheath will be broken by the kosmotropic salt which results in to salt-water sheath. Conclusion: The density, sound velocity and adiabatic compressibility results suggest that phase separation phenomenon is due to the bond breaking and bond making process along with hydrophobic hydration and hydrophobic interactions. The anion S2O32-, SO42- and SO3 2- promote salting-out effect and the strength of these effects decreases in the order S2O32->SO42->SO32-.

Solubilities of H2 in H2O and D2 in D2O with dissolved boric acid and lithium hydroxide

2006 ◽  
Vol 84 (1) ◽  
pp. 65-68 ◽  
Author(s):  
Uncharat Setthanan ◽  
David R Morris ◽  
Derek H Lister
Keyword(s):  
Boric Acid ◽  
Heavy Water ◽  
Aqueous Electrolyte ◽  
Pure Water ◽  
Electrolyte Solutions ◽  
Lithium Hydroxide ◽  
Hydrogen Solubility ◽  
Salting Out ◽  
Temperature Changes ◽  
Specific Parameter

The solubilities of hydrogen (H2 and D2) in aqueous (H2O and D2O) solutions of lithium hydroxide or boric acid have been measured in the temperature range 25–80 °C. Lithium hydroxide and boric acid cause a salting-out effect for H2 and D2. The solubilities of H2 and D2 in aqueous electrolyte solutions exhibit similar responses to temperature changes as those for pure water. The solute specific parameter (hi) for boric acid in light and heavy water is 0.07 ± 0.02 and 0.48 ± 0.26 m3 kmol–1, respectively.Key words: hydrogen solubility, deuterium solubility, salting-out effect.

scholarly journals The Removal of Rare-Earth Metals from Water-Salt Systems – An Innovative Aspect of the Modern Industry

2021 ◽  
Author(s):  
Olga Leonidovna Lobacheva
Keyword(s):  
Rare Earth ◽  
Sodium Dodecyl ◽  
Raw Material ◽  
Ion Flotation ◽  
Water Salt ◽  
Living Organisms ◽  
Effective Use ◽  
Salt Systems ◽  
Theoretical Results

Considering the ever-increasing role of rare-earth elements (REE) in the modern hi-tech field, their effective use has a tremendous significance, although the production process is inevitably linked to the large volumes of industrial ammonia effluents and heavy metal wastes. In the process of metallurgical separation of metals, the emission of large volumes of noxious gases and radioactive substances is inevitable. Lean technogenic raw material processing is sensible under the condition of the development of non-waste technology. The lack of competent regulations governing the disposal of waste containing REE has an impact on adjacent territories, accumulating in water bodies and, as a result, in the human body. Such an impact cannot pass without a trace, however, the ambiguity of opinions in the scientific community regarding the toxic effects of REE on living organisms determines the relevance of a more detailed study of this issue. The paper presents experimental and theoretical results of studies of ion flotation in the aqueous solutions containing ytterbium cations and a surfactant as a collector - sodium dodecyl sulphate (NaDS).

scholarly journals EXTRACTION AND ELECTROPHORETIC DETERMINATION OF VANILLIN IN AQUEOUS SOLUTIONS AND ENERGY DRINKS WITH POLYMERS BASED ON N-VINILFORMAMIDE

2017 ◽  
Vol 60 (8) ◽  
pp. 13
Author(s):  
Nadezhda Ya. Mokshina ◽  
Oksana A. Pakhomova ◽  
Gennadiy V. Shatalov ◽  
Maria S. Lavlinskaya
Keyword(s):  
Aqueous Solutions ◽  
Energy Drinks ◽  
Water Soluble ◽  
Phase System ◽  
Two Phase ◽  
Salting Out ◽  
Water Soluble Polymer ◽  
Oh Groups ◽  
Water Salt

The problem of development of new ways of extraction of vanillin from aqueous mediums of various genesis for the analysis and determination of an anolyte under production of foodstuff and energy drinks was actualized. Two-phase water systems on the basis of water-soluble polymers most fully satisfy requirements for extractive systems. Regularities of interphase distribution of vanillin in a water-salt extraction systems on the basis of poly-N-vinylformamide and N-vinilformamide copolymer with N-vinylimidazole are established. The rate of formation of the two-phase system "water-soluble polymer - water-salt solution of vanillin" is significantly influenced by the molecular mass of the extractant: with increasing intrinsic viscosity, the amount of polymer necessary to form a heterogeneous system in the presence of a salting out agent decreases. Influence of ratio of water and organic phases on effectiveness of extraction of vanillin, including in the presence of a caffeine is studied. Effectiveness of use of extraction systems on the basis of the synthesized copolymers for extraction and elektroforetic determination of vanillin and caffeine is established. During the research some conditions of electrophoretic detecting of vanillin and caffeine were optimized: structure of a buffered solution, type and the concentration of a mitsello adjustable influence the dividing ability of a buffered solution. Distribution coefficients and extent of extraction of vanillin are calculated. Schemes of formation of associates in systems vanillin-polymer are offered. The maximal values of extraction characteristics of vanillin in systems with copolymer are lower, than at extraction in systems with poly-N - vinylformamide. It was established that introduction to system of a component with bonds of N-vinylimidazole leads to formation of intramolecular bonds between OH - groups of N-vinylimidazole and "pyridinic" N-atoms of an imidazolny cycle. The way of electrophoretic selection determination of vanillin and caffeine in energy drinks with preliminary extraction of target components with the use of polymers is developed. Forcitation:Mokshina N.Ya., Pakhomova O.A., Shatalov G.V., Lavlinskaya M.S. Extraction and electrophoretic determination of vanillin in aqueous solutions and energy drinks with polymers based on N-vinilformamide. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 8. P. 13-19.

A method for selective separation of scandium (III) from yttrium and a number of rare-earth elements for its subsequent determination

2018 ◽  
Vol 84 (11) ◽  
pp. 23-27
Author(s):  
M. I. Degtev ◽  
A. A. Yuminova ◽  
A. S. Maksimov ◽  
A. P. Medvedev
Keyword(s):  
Rare Earth ◽  
Aqueous Phase ◽  
Selective Isolation ◽  
Optimum Ratio ◽  
Extraction Condition ◽  
Sulfosalicylic Acid ◽  
Salting Out ◽  
Subsequent Determination ◽  
Toxic Organic Solvents ◽  
Metal Ions Extraction

The possibility of using an aqueous stratified system of antipyrine — sulfosalicylic acid — water for the selective isolation of scandium macro- and microquantities for subsequent determination is studied. The proposed extraction system eliminates the usage of toxic organic solvents. The organic phase with a volume of 1.2 to 2.0 ml, resulting from delamination of the aqueous phase containing antipyrine and sulfosalicylic acid is analysed to assess the possibility of using such systems for metal ions extraction. Condition necessary for the formation of such a phase were specified: the ratio of the initial components, their concentration, presence of inorganic salting out agents. The optimum ratio of antipyrine to sulfosalicylic acid is 2:1 at concentrations of 0.6 and 0.3 mol/liter in a volume of the aqueous phase of 10 ml. The obtained phase which consists of antipyrinium sulfosalicylate, free antipyrine and water, quantitatively extracts macro- and microquantities of scandium at pH = 1.54. Macro- and microquantities of yttrium, terbium, lanthanum, ytterbium and gadolinium are not extracted under the aforementioned conditions thus providing selective isolation of scandium from the bases containing yttrium, ytterbium, terbium, lanthanum, and gadolinium.

scholarly journals Vapor-Liquid Equilibrium Data of Isopropanol-Water-Salt Systems

1970 ◽  
Vol 34 (10) ◽  
pp. 1112-1115,a1 ◽  
Author(s):  
Shuzo Ohe ◽  
Kimihiko Yokoyama ◽  
Shoichi Nakamura
Keyword(s):  
Liquid Equilibrium ◽  
Vapor Liquid Equilibrium ◽  
Equilibrium Data ◽  
Water Salt ◽  
Salt Systems ◽  
Vapor Liquid

Cryocrystallization in water-salt systems and the structural features of highly concentrated solutions

1983 ◽  
Vol 24 (2) ◽  
pp. 209-213
Author(s):  
A. K. Lyashchenko ◽  
A. P. Mozhaev ◽  
S. V. Naumov ◽  
A. V. Golovchanskii
Keyword(s):  
Structural Features ◽  
Concentrated Solutions ◽  
Water Salt ◽  
Salt Systems

Selective Transport of Water-Soluble Proteins from Aqueous to Ionic Liquid Phase via a Temperature-Sensitive Phase Change of These Mixtures

2012 ◽  
Vol 65 (11) ◽  
pp. 1548 ◽  
Author(s):  
Yuki Kohno ◽  
Nobuhumi Nakamura ◽  
Hiroyuki Ohno
Keyword(s):  
Phase Change ◽  
Aqueous Phase ◽  
Selective Dissolution ◽  
Selective Extraction ◽  
Soluble Proteins ◽  
Water Soluble ◽  
Temperature Sensitive ◽  
Salting Out ◽  
Key Factor ◽  
The Difference

Mixtures of some ionic liquids (ILs) and water show reversible phase change between a homogeneous mixture and phase-separated state by a small change in temperature. Some water-soluble proteins have been migrated from the aqueous to the IL phase. When tetrabutylphosphonium 2,4,6-trimethylbenzenesulfonate was used as an IL, cytochrome c (Cyt.c) was found to be extracted from the water phase to the IL phase. Conversely, both horseradish peroxidase (HRP) and azurin remained in the aqueous phase. This selective extraction was comprehended to be due to the difference in solubility of these proteins in both phases. The separated aqueous phase contained a small amount of IL, which induced the salting-out of Cyt.c. On the other hand, condensed IL phase promoted the salting-in of Cyt.c. As a result, Cyt.c was preferably dissolved in the hydrated IL phase rather than aqueous phase. In the case of HRP, there was only a salting-out profile upon increasing the concentration of IL, which induced selective dissolution of HRP in the aqueous phase. These results clearly suggest that the profile of salting-out and salting-in for proteins is the key factor to facilitate the selective extraction of proteins from aqueous to the IL phase.

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