scholarly journals CHANGE IN THERMODYNAMIC CHARACTERISTICS OF HYDRATION OF CARBOXYL FIBER SORBENT IN EXCHANGE OF MAGNESIUM AND CALCIUM CATION

2020 ◽  
Vol 63 (4) ◽  
pp. 42-48
Author(s):  
Yuriy S. Peregudov ◽  
Sabukhi I. Niftaliev ◽  
Anna V. Timkova ◽  
Larisa P. Bondareva ◽  
Aleksey V. Astapov
Keyword(s):  
Ion Exchange ◽  
Gibbs Energy ◽  
Phase Transfer ◽  
Thermodynamic Characteristics ◽  
Ion Exchanger ◽  
Isopiestic Method ◽  
Ionic Form ◽  
Magnesium Ions ◽  
Calcium And Magnesium ◽  
Sodium Form

The relationship between the characteristics of hydration and the selectivity of the fibrous carboxyl sorbent is established. Using the isopiestic method and thermal analysis, the hydration of the carboxyl fiber ion exchanger VION KN-1 in sodium, calcium and magnesium forms was studied. The quantity of absorbed water was determined, including the ratio of kinetically unequal water in the sorbent phase. The amount of water absorbed form of magnesium ion exchanger is greater than calcium, the molar proportion of water distribution varying in the degree of hydration of the magnesium and calcium forms fibers substantially equally. The changes in Gibbs energy of hydration and enthalpy of dehydration of ion-exchange fiber are calculated. The increase in Gibbs energy is due to the absorption of near- hydration water, and water farthest hydration is adsorbed at a constant value of the energy. Its highest values are determined for the magnesium form of the sorbent, and the least-for calcium, which corresponds to the ratio of the absorbed solvent of both forms in the first step of hydration. The exchange isotherms of calcium and magnesium ions on the sodium form of VION KN-1 fiber were obtained. The Gibbs energy of solvent interface transfer was calculated, which represents the difference between the Gibbs energies of ion exchange sorption and the direct exchange of cations, and describes the contribution of the change in sorbent hydration during the transition from one ionic form to another. It is found that the selectivity of extractable fiber ion exchanger to metal cations depending on the change in the sorbent during the hydration of ion exchange, which is energetically favorable process and promotes ion-exchange sorption. Carboxyl cation exchanger is more selective for magnesium ions than calcium ions, as confirmed by phase transfer energy high values solvent and less water released during the transition from the sodium form to the magnesium than during the transition to the calcium.

scholarly journals Equilibrium of ion exchange of calcium, magnesium and potassium for proton on fibrous carboxylic ion exchanger

2021 ◽  
Vol 57 (2) ◽  
pp. 135-143
Author(s):  
V. S. Soldatov ◽  
N. V. Vonsovich ◽  
T. A. Korshunova
Keyword(s):  
Ion Exchange ◽  
Ion Exchanger ◽  
Hydrogen Ion ◽  
Ionic Form ◽  
Potassium Ions ◽  
Titration Curves ◽  
Wide Range ◽  
Calcium Magnesium ◽  
Calcium And Magnesium ◽  
Low Solubility

By the method of potentiometric titration of a fibrous aminocarboxylic polyampholyte with a predominant content of carboxyl groups, the equilibrium of the cation exchange of calcium, magnesium, and potassium ions for a hydrogen ion was studied. Due to the low solubility of calcium and magnesium hydroxides in these cases, titration was carried out by Ca(OH)2 and Mg(OH)2, which are formed in solution upon contact with the H-form of the ion exchanger оf increasing portions of solid CaO and MgO. This made it possible to obtain titration curves in a wide range of pH and calcium and magnesium chlorides concentration (0–0.1 eq./L). The dependences of the swelling of ion exchangers on the neutralization degree with the bases of the studied cations are obtained. The coefficients of ion-exchange equilibria are calculated. It was found that the swelling of the ion exchanger is relatively little dependent on its ionic form. The ion exchanger has a higher affinity for calcium than magnesium ion.

scholarly journals Investigation of the Process of Tartaric Acid Separation on Amberlite XAD2 Impregnated with Amberlite LA-2

2012 ◽  
Vol 7 (2) ◽  
pp. 116-123
Author(s):  
N. Marchitan
Keyword(s):  
Ion Exchange ◽  
Gibbs Energy ◽  
Tartaric Acid ◽  
Ion Exchanger ◽  
Model Systems ◽  
Ecological Chemistry ◽  
Impregnation Process ◽  
Ion Exchange Separation ◽  
Liquid Ion Exchanger

This work describes an investigation of the process of reactive ion-exchange separation of tartaric acid from model systems with macroreticular resin AmberliteXAD2 impregnated with liquid ion-exchanger Amberlite LA-2 in batch equipment.The condition of Amberlite XAD2 impregnation process was investigated. Freudlichand Langmuir equations were verified and values of enthalpy, entropy and Gibbs energy were calculated. This article is an extended abstract of a communicationpresented at the Conference Ecological Chemistry 2012.

Thermodynamic properties of montechellite

2019 ◽  
Vol 64 (12) ◽  
pp. 1274-1280
Author(s):  
L. P. Ogorodova ◽  
Yu. D. Gritsenko ◽  
M. F. Vigasina ◽  
A. Yu. Bychkov ◽  
D. A. Ksenofontov ◽  
...  
Keyword(s):  
High Temperature ◽  
Gibbs Energy ◽  
Solution Calorimetry ◽  
Thermochemical Study ◽  
Gibbs Energy Of Formation ◽  
Calvet Microcalorimeter ◽  
Magnesium Orthosilicate ◽  
Calcium And Magnesium ◽  
The Enthalpy Of Formation ◽  
Energy Of Formation

A thermochemical study of natural calcium and magnesium orthosilicate ─ monticellite (Ca1.00Mg0.95)[SiO4] (Khabarovsk Territory, Russia) was carried out on the Tian-Calvet microcalorimeter. The enthalpy of formation from the elements fHоel(298.15 K) = -2238.4 4.5 kJ / mol was determined by the method of high-temperature melt solution calorimetry. The enthalpy and Gibbs energy of formation of monticellite of the theoretical composition of CaMg[SiO4] are calculated: fH0el(298.15 K) = -2248.4 4.5 kJ/mol and fG0el(298.15 K) = -2130.5 4.5 kJ/mol.

Maize Stalk as Natural Ion Exchanger for Hazardous Pollutants

2017 ◽  
Vol 68 (8) ◽  
pp. 1726-1731
Author(s):  
Nicoleta Mirela Marin ◽  
Luoana Florentina Pascu ◽  
Ioana Stanculescu ◽  
Ovidiu Iordache ◽  
Denisa Jianu ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Kinetic Models ◽  
High Selectivity ◽  
Ion Exchanger ◽  
Exchange Equilibrium ◽  
Waste Waters ◽  
Cationic Species ◽  
Hazardous Pollutants ◽  
Tailing Ponds

This paper recommends maize stalk as a cheap natural ion exchanger. Ion exchange equilibrium was studied using thermodynamic and kinetic models. The results showed a high selectivity towards cationic species of antimony (III), molybdenum (VI), lead (II) and arsenium (III). Waste waters and sediments from tailing ponds samples were analysed.

The Role of Calcium and Magnesium Ions in Uptake of β-Amyloid Peptides by Microglial Cells

2006 ◽  
Vol 19 (3) ◽  
pp. 683-696 ◽  
Author(s):  
N. Choucair ◽  
V. Laporte ◽  
R. Levy ◽  
C. Tranchant ◽  
J.-P. Gies ◽  
...  
Keyword(s):  
Microglial Cells ◽  
Magnesium Ions ◽  
Amyloid Peptides ◽  
Β Amyloid ◽  
Calcium And Magnesium ◽  
Calcium And Magnesium Ions

USING MALIC ACID SOLUTIONS FOR THE HYDRATION OF VEGETABLE OILS AND LECITHIN PRODUCTION

2020 ◽  
Author(s):  
Л.А. МАРЧЕНКО ◽  
Т.Н. БОКОВИКОВА ◽  
Е.В. ЛИСОВАЯ ◽  
С.А. ИЛЬИНОВА ◽  
Е.П. ВИКТОРОВА
Keyword(s):  
Malic Acid ◽  
Complex Compounds ◽  
Point Of View ◽  
Magnesium Ions ◽  
Ph Values ◽  
Calcium And Magnesium ◽  
The Stability ◽  
The Cost ◽  
Calcium And Magnesium Ions

Исследована возможность применения яблочной кислоты (ЯК) в качестве гидратирующего агента для перевода негидратируемых форм фосфолипидов в гидратируемые. Выбор ЯК обусловлен ее стоимостью, которая в 1,5 раза меньше стоимости янтарной кислоты, широко применяемой в качестве гидратирующего агента, а также большей доступностью с точки зрения промышленного производства. Исследование процесса комплексообразования и определение состава комплексных соединений ЯК с ионами кальция и магния осуществляли методом потенциометрического титрования. Установлено, что внесение в раствор ЯК ионов кальция и магния приводит к снижению значений рН, что свидетельствует о наличии комплексообразования в указанных системах. Наиболее устойчивыми являются комплексы ионов кальция и магния с непротонированным лигандом при соотношении Ме2 : лиганд 1 : 1. В процессе комплексообразования ионы Ca2 и Mg2 вытесняют протоны только карбоксильных групп ЯК, которая с ионами кальция образует более устойчивые комплексы, чем с ионами магния. Показано, что устойчивость комплексов ЯК с ионами кальция и магния значительно выше, чем устойчивость комплексов фосфатидилсеринов и фосфатидных кислот с указанными ионами. Использование водных растворов ЯК в качестве гидратирующего агента позволит повысить эффективность процесса гидратации и увеличить выход фосфолипидов и, следовательно, готового продукта лецитина. The possibility of using malic acid (MA) as a hydrating agent for converting non-hydrated forms of phospholipids into hydrated ones has been investigated. The choice of MA is due to its cost, which is 1,5 times less than the cost of succinic acid, as well as greater availability from the point of view of industrial production. The study of the complexation process and determination of the composition of complex compounds of MA with calcium and magnesium ions was carried out by the method of potentiometric titration. It was found that the introduction of calcium and magnesium ions into the MA solution leads to a decrease in pH values, which indicates the presence of complexation in these systems. Complexes of calcium and magnesium ions with an unprotected ligand at a ratio of ME2 : ligand 1 : 1 are the most stable. In the process of complexing, Ca2 and Mg2 ions displace protons only of the carboxyl groups of MA, which forms more stable complexes with calcium ions than with magnesium ions. It is shown that the stability of MA complexes with calcium and magnesium ions is significantly higher than the stability of phosphatidylserine and phosphatidic acid complexes with these ions. Using water solutions of MA as a hydrating agent will increase the efficiency of the hydration process and increase the yield of phospholipids and, consequently, the finished product lecithin.

Sign in / Sign up

Export Citation Format

Share Document