Sorption of Fulvic Acids from the Neva River on Anion Exchangers Based on Styrene-Divinylbenzene Copolymer

Sorption of fulvic acids (FA) on anion exchangers based on styrene-divinylbenzene copolymerwas studied.     

Sorption of Uranium from Sulfuric Acid Leaching Solutions by Strongly Basic Anion Exchangers

The equilibrium and kinetic characteristics of uranium sorption from simulated sulfuric acid leaching solutions by AMP, Lewatit K 6367, Purolite A 500, Purolite A 600, and AM-p gel-like and porous strongly basic anion exchangers were studied.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 5, 2005, pp. 736–740.Original Russian Text Copyright © 2005 by Kolomiets, Troshkina, Sheremet’ev, Konopleva.     

Precipitation Recovery of Rhenium(VII) from Aqueous Solutions with Coagulating Cationic Polyelectrolyte

Rhenium(VII) recovery from dilute aqueous solutions by coprecipitation with VA-212 cationic polyelectrolyte in the presence of nitrate ions was studied.     

Sorption of Chromium(VI) from Aqueous Solutions on AM-2b Anion Exchanger

Sorption of chromium(VI) from a solution with the initial concentration of CrO₃ of up to 30 mg dm^{- 3} on a commercial macroporous AM-2b anion exchanger pretreated by various methods was studied. The optimal conditions for efficient sorption were found.     

Vanadium(V) Removal from Aqueous Solutions and Real Wastewaters onto Anion Exchangers and Lewatit AF5

Adsorption abilities of weakly (Purolite A830), weakly basic/chelating (Purolite S984), and strongly basic (Lewatit MonoPlus SR7, Purolite A400TL, Dowex PSR2, Dowex PSR3) ion exchange resins of different functional groups and microporous Lewatit AF5 without functional groups towards vanadium(V) ions were studied in batch and column systems. In the batch system, the influence of the sorbent mass (0.01–0.1 g), pH (2–10), the phase contact time (1–1440 min),and the initial concentration (5–2000 mg/L) were studied, whereas in the column system, the initial concentrations (50, 100, and 200 mg/L) with the same bed volume and flow rate (0.4 mL/min) were studied. Desorption agents HCl and NaOH of 0.1–1 mol/L concentration were used for loaded sorbent regeneration. The pseudo-first order, pseudo-second order and intraparticle diffusion kinetic models as well as the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherm models were used to describe kinetic and equilibrium data to acquire improved knowledge on the adsorption mechanism. The desorption efficiency was the largest using 0.5 mol/L NaOH for all sorbents under discussion. Purolite S984, Purolite A830, and Purolite A400TL, especially Purolite S984, are characterized by the best removal ability towards vanadium(V) from both model and real wastewater.     

Flocculation of Butadiene-Styrene Latex with Polymeric Ammonium Salts of N,N-Dimethylaminoethyl Methacrylate and Mineral Acids

The flocculation performance of cationic polyelectrolytes (polymeric ammonium salts of N,N-dimethylaminoethyl methacrylate) and mineral acids (HCl, HNO₃, H₂SO₄, H₃PO₄) in recovery of rubber from SKS-30 ARK butadiene-styrene latex was studied.     

Specific Features of Lincomycin and Gentamicin Sorption from Aqueous Solutions of Their Salts and Bases by Monocarboxyl Cellulose

Sorption of antibiotics lincomycin and gentamicin from aqueous solutions of their salts and bases by the samples of monocarboxyl cellulose with different content of carboxyl groups was studied. The nature of sorption interactions and factors affecting this process was disclosed. Electrostatic interactions were shown to play a determining role in the mechanism of the antibiotic binding with monocarboxyl cellulose. Single-charged lincomycin was found to be sorbed by monocarboxyl cellulose via stoichiometric binding characterized by the 1 : 1 sorbent-to-sorbate ratio. Multicharged gentamicin was also sorbed from solutions of its sulfate and base due to electrostatic interactions; however, several protonated amino groups of gentamicin molecule are involved in binding, thus resulting in the cross-linking of monocarboxyl cellulose macromolecules.     

Thermodynamic Analysis of Cerium(III) Extraction from Sulfate Solutions with Salts of Quaternary Ammonium Bases

Cerium(III) distribution between an aqueous sulfate solution and a solution of trialkylbenzylammonium sulfate in xylene was studied. The Ce(III) distribution coefficient grows with increasing pH. The extraction is provided by the formation of cerium mono- and disulfate complexes in the aqueous phase. Schemes of extraction equilibria are proposed and Gibbs energies and equilibrium constants are found.     

Regeneration of VA-212 Cationic Polyelectrolyte Exhausted in Rhenium(VII) Recovery from Aqueous Solutions by Complexation-Ultrafiltration Technique

A procedure was developed for regeneration of VA-212 cationic polyelectrolyte exhausted in recovery of rhenium(VII) from aqueous solutions by complexation-ultrafiltration technique. The regeneration includes polyelectrolyte coagulation by displacement of perrhenate by nitrate anions, ultrafiltration, and dissolution of the filtered sediment with reducing agent.     

Aminoguanidinium closo-Borates and Their Reactions with Copper(II) Salts in Aqueous Solutions

Aminoguanidinium hexa-, deca-, and dodecaborates of (AguH)₂B _n H _n · xH₂O (Agu = (CN₄H₆), n= 6, 10, 12; x= 1, 2) composition were synthesized and studied by elemental analysis, magnetic susceptibility, and IR spectroscopy methods. Their reactions with copper(II) salts in aqueous solutions were investigated. A cation–anion interaction was shown to occur in aminoguanidinium closo-borates and to increase in the series B₁₂< B₁₀< B₆. Depending on the closo-anion (B _n H^2– _n ), the reactions of aminoguanidinium closo-borates with copper(II) salts in aqueous solutions yield either complex compounds (n= 10, 12) or metallic copper (n= 6).     

硼酸盐晶体及其溶液结构研究现状

硼酸盐结构十分复杂,主要针对硼酸盐晶体结构和硼酸盐水溶液结构问题,总结了水合硼酸盐晶体结构及其结晶行为,归纳了硼酸盐水溶液中硼酸盐的主要存在形式及其结构研究,并侧重介绍和评价了电导/电势滴定、红外(IR)、拉曼光谱(Raman)、11B核磁共振等方法在硼酸盐溶液结构研究方面的进展,指出了未来的发展方向.     

芳基膦(胂)酸及其盐的合成、结构与倍频效应研究

本文基于将无机非线性光学材料的有效基团(畸变阴离子基团)及有机共轭体系结合为一体的设想,用改进的Doak-Freedman法合成了一系列芳基膦(胂)酸及其盐共25个化合物,讨论了分子的电子性质及其在晶体中的排列方式.实验结果表明,在这类化合物的分子内存在着一定的电荷转移;对甲苯膦酸的晶体结构分析表明,分子间存在着氢键作用,使分子呈二聚的排列方式.在所合成的化合物中,有6种表现出宏观倍频效应.     

Study of Sorption Properties for Lead(II) Ions Exhibited by Anion Exchangers Synthesized on the Basis of Aromatic Hydrocarbons,Epichlorohydrin, and Polyethyleneimine

Aromatic hydrocarbons, epichlorohydrin, and polyethyleneimine were used to synthesize polyfunctional anion exchangers. IR spectroscopy and elemental analysis were used to examine their composition and structure. The method of classical polarography was employed to examine the process of extraction of lead ions and determine the dependences of the sorption of lead(II) ions in the static mode on the solution acidity, concentration of metal ions, and duration of contact between ion exchangers and a Pb(NO₃)₂ solution. It was found that the ion exchangers possess high sorption properties for lead ions.     

Sorption of Lead(II) from Aqueous Solutions by Synthetic Zeolites

A comparative study of the sorption of lead(II) from dilute aqueous solutions by synthetic faujasites, chabazites, mordenites, erionites, phillipsites, and type A zeolites was performed. The most promising sorbents are low-silica chabazites and potassium erionites with relatively high SiO₂/Al₂O₃ ratio.     

Sorption of Some Metal Ions on Inorganic Electron and Ion Exchangers Based on Zirconium(IV)

Conditions of sorption of nonferrous metal ions on inorganic electron and ion exchangers based on zirconium(IV) were analyzed. The sorption capacity was evaluated as influenced by pH, concentration, and temperature of the contacting solutions and nature and chemical composition of the ion exchanger.     

Electronic Spectra and Protonation of 1,4-Di(arylamino)anthraquinones and Their Monodimethylformamidinium Salts in Acid Solutions

Electronic spectra of arylaminoanthraquinones and their amidinium salts in acids were studied, and experimental data on electrophilic substitution of diarylaminoanthraquinone amidinium salts in acetic and sulfuric acids of various concentrations were considered.     

Sorption of Tc(IV) and Tc(VII) on Soils: Influence of Humic Substances

The technetium sorption behaviour in different samples of soils was studied under aerobic conditions. Tc(VII) was reduced to Tc(IV) by Sn²⁺ ions. About 99% of reduced technetium is absorbed by the soils under investigation. Sorption of TcO₄ ^– was studied in short-term (1-hour) and long-term (1-month) experiments. Sorption of TcO₄ ^– in presence of sodium humate (Aldrich) was generally lower than from pure water (from 99% to 12%) and depends on the depth of origin of the ground. Immobilisation of TcO₄ ^– after sorption on superficial sample of soils was studied by paper chromatography. Oxidation of Tc(IV) in presence of NO₃ ^– and NO₂ ^– (concentration range 10^–1–10^–5 mol·dm^–3) ions was studied as a function of time and concentration of NO₃ ^– and NO₂ ^– ions. The content of Tc(IV) in NO₃ ^– and NO₂ ^– solutions decreases with time (46 hours) relatively slowly.     

Sorption of Copper(II) from Chloride Solutions by Carbonate-containing Technological Waste

Absorption of copper(II) ions from copper chloride solutions by a technological carbonate-containing waste was studied in relation to concentration of starting solutions (1-25 wt %), amount of sorbent added, and time.     

Use of Different Salt Solutions in Salting-Out TLC of Co(III) Complexes on Silica Gel

Saturated aqueous solutions of 28 different salts have been studied as a potential mobile phases for salting-out thin-layer chromatography, on silica gel, of a series of four mixed bis-aminocarboxylato cobalt(III) complexes. In addition, by linear regression analysis of chromatographic data obtained for fifteen mixed aminocarboxylato Co(III) complexes (four series) with solutions of ammonium chloride, three alkali metal chlorides, and four alkaline earth metal chlorides, four linear dependences previously established on different adsorbents with (NH₄)₂SO₄ solutions were confirmed. The qualities of the separations achieved with the salts were compared and Li⁺, Mg²⁺, and Ca²⁺ chlorides are proposed as the most suitable.     

Composite Ion Exchangers Based on KU-23 and KM-2P Cation Exchangers and Nickel(III) Hydroxide and Their Use for Purification of Nickel Sulfate Solutions To Remove Cobalt(II) Impurity

A method of preparing composite ion exchangers based on macroporous cation exchangers and nickel(III) hydroxide was developed, and their suitability for deep purification of nickel(II) sulfate solutions to remove small amounts of cobalt(II) was demonstrated.