Home – Home – Jornals – Chemistry for Sustainable Development 2013 number 2

Acid catalytic condensation of 1,3-butadiene with para -quinones and the oxidation of resulting adducts can be performed in one technological stage in the presence of the aqueous solutions of Мо–V–P heteropolyacids (HPA) of general composition H_aP_zMo_yV_xO_b. These solutions possess bifunctional catalytic properties being strong Brønsted acids and rather strong reversibly acting oxidizers at the same time. The condensation of 1,4-naphthoquinone with 1,3-butadiene in HPA solutions leads to obtaining 9,10-anthraquinone (AQ) in mixture with tetrahydroanthraquinone (THA) and dihydroanthraquinone (DHA). In the course of a single-stage process without organic solvents, the HPA solution is reduced and poorly soluble mixture of THA, DHA and AQ (up to 50 %) precipitates almost quantitatively from the solution. The yield and purity of AQ can be improved substantially due to the use of organic solvents miscible with water (for example, acetone, 1,4-dioxane), as well as high-vanadium HPA of the composition H₁₅P₄Mo₁₈V₇O₈₉ and H₁₇P₃Mo₁₆V₁₀O₈₉. Optimization of the process allowed us to obtain the product containing not less than 90 % AQ. Results achieved in the work open outlooks for the development of low-waste process for the production of AQ from 1,3-butadiene and 1,4-naphthoquinone.

Atmospheric aerosols inherent in two areas of the Far East cities such as the Vladivostok and Ussuriysk were studied. Three of the 21 pairs of the samples of fresh snow and dry air suspensions taken in different parts of these cities exhibited the presence of iron, chromium, lead and zinc nano- and microparticles. Therewith, the nanoparticles were registered for the samples taken near the electroplating production enterprises, whereas the microparticles were observed near the roads with an intense traffic.

Studies were performed concerning the process of obtaining noble metals (gold, silver, platinum, palladium) and tellurium, involving the following process stages: dissolving the gold and silver alloy in nitric acid solutions in the presence of ammonium nitrate under the gas phase pressure; purifying the leaching solutions via sorption (from platinum and palladium) and via hydrolytic precipitation (from copper and tellurium); electrochemical extraction of silver-containing solutions to produce cathode silver; conditioning and refining the gold sludge; an electrochemical extraction of eluates containing platinum group metals; obtaining tellurium concentrate. The number and type of linearly independent reactions have been found out for the dissolution of the parent alloy, key components for the stoichiometric description of chemical reactions in the system have been identified. A mathematical evaluation of quantitative changes in the complicated heterogeneous system with polyvalent nitrogen is presented.

Accumulation levels were determined for polycyclic aromatic hydrocarbons (PAHs) in naturally occurring objects over the territory of dispersing the emissions of the Irkutsk Aluminum Plant “IrkAZ–Sual”: in the snow cover, soil, pine needles (Pinus sylvestris L.) and larch needles (Larix sibirica), in water and the bottom sediments of the. Olkha River, as well as in the near-surface aerosols in Shelekhov City. An estimation was performed for the level of contamination with PAH compounds in the area of the Shelekhov City within the framework of the MPC and background levels, a conclusion has been drawn concerning the distribution of PAH emissions from the source over a limited area. Among the isolated fractions of PAHs, using a gas chromatography-mass spectrometry technique there have been identified and determined 14 arenes including those from the list of priority organic pollutants.

Results of the investigation of cytotoxic and immunomodulating action of silver nanocomposites Ag15 (7.8 % Ag) and Ag13 (5 % Ag) with poly(1-vinyl-1,2,4-triazole) and platinum with arabinogalactan on primary and transformed human cells in vitro are presented. It is demonstrated that nanocomposites of metals with biopolymers possess more clearly pronounced cytotoxic effect in comparison with metal nanoparticles and do not induce inflammation in cell lines under investigation. It is established that silver nanocomposite Ag15 possesses selective cytotoxicity with respect to the cells of cervical adenocarcinoma HeLa.

Results are presented concerning the recovery of an oil sludge model from the contamination by means of a complex microbiological and physicochemical method. It is demonstrated that washing with a detergent composition results in a 55–75 % decrease of soil contamination level. The subsequent biodestruction by native microflora further reduces the contamination by 20–30 % per month. In the case of the mechanical part of the sludge, the microflora is worthwhile for stimulation by nitrogen and phosphorus containing mineral substrates, whereas in the case of spent water the mineral nutrition can be provided by the components of the composition. Changing the structural and group as well as the individual composition of hydrocarbons in the spent water corresponds to the initial stage of biodestruction, whereas that in the washed soil corresponds to the middle stage thereof, which indicates a low activity of the indigenous microflora.

The process of methane combustion in a fluidized bed of spherical oxide catalyst containing mixed copper and magnesium chromite on toughened alumina (IK–12–73) depending on the temperature and the concentration of methane in the mixture with air was studied. It has been demonstrated that the conversion level of methane oxidation into CO₂ in the case of the methane content equal to 2 % increases from 72 % at 500 °С to 99 % at 700 °С. Increasing the concentration of methane to 8 % does not causes reducing the conversion level of methane oxidation within the temperature range 600–750 °С. It has been demonstrated that the concentration of nitrogen oxides in the course of methane combustion at the temperature values ranging within 500–750 °С does not exceed 3.5 ppm. The presence of H₂ and CO in the reaction mixture does not causes increasing the conversion level of methane oxidation when the volume ratio CH₄/(CO + H₂) = 4 : 19.

Results of the investigation of cytotoxic and immunomodulating properties of gold nanoparticles of different sizes (12, 16, 22 and 35 nm) on primary and transformed cells in vitro are presented. Their localization and distribution in cells are studied. It is established that gold nanoparticles are not toxic within concentration range 0.06–6 μg/mL for all the cell cultures used, actively penetrate into the cell and get accumulated inside the vacuoles of different sizes, selectively activate the anti-inflammatory immune response depending on nanoparticle size and cell type.

In surface water and bottom sediments of the Gusinoye Lake (the Lake Baikal basin), there were concentration profiles determined for 19 polycyclic aromatic hydrocarbons (PAHs). It has been found that the total PAH content amounts to 7.1–33.7 ng/L for the surface water and 42.6–221.8 ng/g of dry solid matter for bottom sediments. It has been demonstrated that the presence of PAHs in the samples of surface water and bottom sediments of the Gusinoye Lake could mainly be caused by local sources having pyrolytic nature.

In the bottom sediments and surface water of the Gusinoye Lake (the Lake Baikal basin) there were content and profile values for organochlorine pesticides and polychlorinated biphenyls determined. An evaluation was performed concerning the ways of coming thereof in the Gusinoye Lake It has been found that the sources of these ecotoxicants are mainly local.

Experimental results are presented on studying the ionic mobility of metals in geotechnogenous solutions from an opencast mine of the Sherlovaya Gora tin-polymetallic deposit in the presence of zeolite-containing rocks taken from the Shivyrtuy deposit (Transbaikalia). A high sorption activity of zeolite-bearing rocks is revealed concerning almost all the metal ions in solution. Concentrating the large amounts of zinc, iron, manganese ions and other elements in the solid phase could be caused replacing the ions of sodium in the structure of clinoptilolite by the mentioned ions.

A topological thermodynamic analysis was performed for a butanol–toluene mixture produced as a waste in the industry of paint–and–lacquer materials. Liquid–liquid equilibrium was experimentally studied in the system ethanol–toluene–chlorobenzene–water. Main pathways for separating a butanol–toluene mixture have been synthesized as flow graphs. A rectification analysis was performed for the system under study. Choosing a separating agent (benzene) has been performed. Variants were proposed for the technological schemes of the butanol–toluene mixture separation via combining simple and azeotropic distillation techniques.

Enzymatic hydrolysis of technical cellulose of miscanthus in the acetate buffer with enzymatic preparation BrewZyme BGX was investigated. A linear dependence of the final concentration of reducing substances on the initial substrate concentration was established. The enzymatic hydrolysis of cellulose in aqueous medium with sequential addition of enzymatic preparations BrewZyme BGX, Celluxil, CelloLux-A was studied. The results of fermentation of the hydrolysates of Miscanthus technical cellulose obtained in the aqueous medium provide evidence of their sound quality, so these hydrolysates can be used for conversion into ethanol, gel film of bacterial cellulose and other products of microbiological transformation.

Regularities of the adsorption of L-glutamic acid on brushite were studied. Brushite is a mineral component of pathogenic new growth formed at the initial stages of calculus formation. It was established that the interaction of calcium hydrophosphate dihydrate and the amino acid is described within Langmuir’s theory (r² = 0.99). Monomolecular adsorption layer is formed as a result of coordination of protonated terminal carboxyl groups of glutamic acid with positively charged groups СаОН⁺ and/or СаН₂РО₄⁺ on the surface of brushite crystal.

A principally new method of immobilization was developed for titanium silicalite (TS–1), the catalyst of liquid-phase hydrocarbon oxidation. The method involves encapsulation of catalyst particles in a polymer matrix. A series of catalysts was synthesized using different types of polymer matrices for practical implementation in oxidation processes. The optimal composition of the components of catalytic system and the type of polymer matrix for practical use in liquid-phase oxidation of the hydrocarbons of С₆–С₉ fraction were established, with the use of 30 % aqueous hydrogen peroxide solution as the oxidizer and methanol as a solvent.