K. A. Burkov

Organic solvent effect on the solution-solid phase equilibria in the systems CuCl2-L-H2O (L = DMSO, DMF, acetonitrile) at 25°C

A solution-solid equilibrium in ternary water-organic systems CuCl2-L-H2O (L = dimethyl sulfoxide, N,N-dimethyl formamide, and acetonitrile) at 25°C was studied. The expansion of crystallization branches of individual solvates CuCl2·xL varies in parallel to the donor power of organic solvents. The existence of the mixed crystal-solvates CuCl2·2H2O·2(CH3)2SO, CuCl2·2H2O·2(CH3)2NCHO, CuCl2·H2O·(CH3)2NCHO, CuCl2·2H2O·CH3CN, and CuCl2·3H2O·2CH3CN in the studied systems was proved. Various donor power of oxygen-containing solvents determines the composition of the first coordination sphere of the copper ion in the specified compounds: the coordination of the both solvents in the mixed crystal-solvates with DMF and the absence of water in the nearest environment of the copper(II) ions in the CuCl2·2H2O·2(CH3)2SO compound.

Red mud for purification of galvanic wastewater

A study of a coagulant-adsorbent, new agent for treatment of industrial waste water, which is modified red mud, a residue from alumina manufactures. The efficiency of the coagulant-adsorbent use was demonstrated for the purification of waste water from heavy metals.

Adsorption of copper(II) ions from aqueous solutions on alumina industrial wastes

Equilibrium adsorption of copper(II) ions on red mud (alumina industrial wastes) modified by various methods was studied. The effect exerted by the nature the modifier (NaHSO4, NaCl + HCl, and H2SO4) on the sorption activity of red mud was determined.

Solubility of d-elements salts in organic and aqueous-organic solvents: IV. Solubility of cadmium chloride

Solubility of cadmium chloride at 25°C in four ternary systems containing mixed water-organic solvents was measured by the isothermal saturation method. Dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, and 1,4-dioxane were used as organic components. In all systems the organic component addition provides a salting-out effect within the whole range of the binary solvent compositions.

Determination of Solutions Density by the Dilatometric Titration Method

A new approach to the determination of solutions density based on dilatometric titration data was developed. The results of testing this method by the example of dilution of a sodium chloride solution are presented. The method allows density of solutions to be determined with a high accuracy (±1×10−5 g cm−3) in a wide concentration range in the course of a single experiment.

Volume properties of the hydrolyzed aluminum species

The composition of polynuclear aluminum hydroxo complexes, their hydrolysis constants, and the volume changes due to complex formation have been determined by CPESSP software analysis of the potentiometry and dilatometry data.

Solution-solid phase equilibrium in the systems MBr2-NR4Br-H2O (M = Cd, Cu, Co; R = Me, Et, Bu) at 25°C

The solubility diagrams in ternary MBr2-NR4Br-H2O systems (M = Cd, Co; R = Me, Et, Bu) at 25°C were determined by isothermal saturation. The composition and crystallization range of solid compounds occurring in equilibrium with the liquid phase were found. The effects of ion hydration, association of tetraalkylammonium salts, and complex formation with d-elements on the solution-solid phase equilibrium were estimated.

Anion influence on the solution-solid phase equilibria in the MX2-NEt4X-H2O systems (M = Cd, Cu, Co; X = Cl, Br) at 25°C

Solubility of the ternary systems M-NEt4Cl-H2O (M = Cd, Cu, Co) at 25°C was determined by the method of isothermal saturation. Compositions and fields of crystallization of solid compounds in equilibrium with a liquid phase were determined. Changes in the processes of hydration, association of tetraethyl ammonium salts, and acido-complex formation of d-element ions on the replacement of a halide anion affect the solution-solid phase equilibria in the studied systems.