Problems of Chemistry and Chemical Technology

Fine-Dispersed Iron (III) Oxyhydroxides Synthesis: Carbamide Precipitation

The conditions of carbamide precipitation synthesis of fine-dispersed iron (III) oxyhidroxides from iron (III) sulphate and nitrate solutions were found out. In order to determine the necessary precipitant amount potentiometric precipitation titration of iron (III) sulphate and nitrate solutions with ammonia and hydrolyzed carbamide solutions were carried out. The results of these researches are expounded.

Influence of Preconditioning on the Absorbency and Strengh of Ammonium Nitrate Granules Grade B

The retention capacity of granulated ammonium nitrate grade B with respect to the liquid fuel due to pretreatment of the granules has been increased, and energy-condensed systems for mining have been developed. Processing technology including opening of hard shell of granules without formation of through pores and creating a rigid framework of slightly soluble compounds in the pores. It has been found, that treatment with a solution of iron (III) chloride and further heating provides formation of iron (III) hydroxyl compounds framework with the developed surface in the pores of granules.

Peculiarities of Sorbtion of Phosphates by Hydrous Oxides of the Elements of III and IV Groups

Binary mixtures containing hydrous oxides of titanium, aluminum, lanthanum, and cerium with various ratio of ingredients have been synthesized by means of co-precipitation method from water solutions. The physical and chemical properties of the target materials have been characterized by X-ray diffraction, scanning electron microscopy, IR spectroscopy, porosity studies and pH titration. The sorption affinity of binary mixtures towards phosphate ions has been studied.

Influence of Layered Nanofillers on Percolation Properties of Systems Based on Polypropylene Glycol and Carbon Nanotubes

By using impedance spectroscopy and optical microscopy methods the investigation of electrical properties of systems based on polypropylene glycol was conducted. It was shown that adding exfoliated layered fillers to the system shifts percolation threshold to low concentration of nanotubes.

Cleaning of Contaminated Waters Against U and Cr Compounds Using Pillared Al- and Al/Fe-Clays

In this paper a comprehensive study of adsorption properties of modified clay minerals with polyoxocomplexes (POM) of iron and aluminium with regard to removal of heavy metal ions from an aqueous medium was carried out. To determine changes in structure characteristics of the intercalated minerals have been used methods of X-ray diffraction, nitrogen adsorption with calculated specific surface area and pore size distribution, as well as adsorption of Chromium (VI) and Uranium (VI) ions from aqueous solutions at various pH values.

Reducing the concentration of Ca2+ Ions in Water Using Ultra- and Nanofiltration Ceramic Membranes

The main regularities of processes of water purification from Ca2+ ions using ultra- and nanofiltration ceramic membranes, in particular, the influence of the operating pressure, the duration of the experiments, the concentrations of Ca2+ ions in the original solution and its temperature to reduce the content of these ions in the filtrate were identified. The cleaning process of the model solution CaCl2 was carried out on an experimental installation of baromembranes using ultra-and nanofiltration tubular membranes of ceramic oxide (produced in Germany).

Regulation of Properties of Dispersions for Their Electrokinetic Treatment

For efficient processing of disperse systems based on the use of external electric fields the highest possible velocities of electrophoresis and electroosmosis for a particular system should be ensured. In case of dispersion, which includes a clay component, the main factor that allows adjusting of its electrokinetic properties is pH of equilibrium solution. In this regard, in present work the kinetics of changes in pH of the pore solution with the introduction of acidic and alkaline solutions (NaOH and HCl) is studied.

Methodology of Energy Consumption Assessment for the Grain Materials Dryer with Shelf Elements

The article is devoted to the methodology development for the technological regimes of the drying process determining in gravity shelf dryers. This methodology is based on a joint analysis of the fluidized bed formation conditions and optimal energy costs of the process. The drying agent consumption, which provides the fluidization beginning of granular material in the apparatus, is determined analytically. A decrease of dryer’s performance depending on porosity which is beyond the operating range is shown in this article.

Detection of Allelic Variants of Wax Gene among National and Foreign Barley Varieties

The objective of the present study was to apply of the molecular marker system for detection of the allelic variants of the Wаx gene. Starch pasting properties are very important factors in malting, food processing and feed quality of barley cultivars. Therefore, it is important to control of the amylose/amylopectin ratio in the barley starch. The Wаx locus of barley (Hordeum vulgare L.) is responsible for the amylose endosperm biosynthesis.

Relation of surface chemistry with properties of skn active carbons

In this paper, we synthesize active carbon samples with various content of nitrogen and oxygen of heteroatoms, as well as surface functional groups. We determine the specific surface area and porosity of the obtained carbon, study its behaviour in the model oxide reduction processes, notably electrochemical oxygen reduction and catalytic decomposition of hydrogen peroxide.