Home – Home – Jornals – Chemistry for Sustainable Development 2013 number 4

A review of hepatotoxic microcystins produced by cyanobacteria of different genera is presented. The chemical structure and properties of microcystins, the mechanism of their action and toxicokinetics are considered. Methods of microcystin analysis and the genetic basis of their production are described. The results of the studies of cyanobacteria and their toxins (microcystins) in different water reservoirs of Russia, Belarus and Ukraine are presented.

Properties of fibrous petroleum collectors obtained by non-isobaric thermal treatment of various kinds of polystyrene raw material with water vapour were studied. It was shown that these sorbents possess high sorption capacity with respect to petroleum products and can be used as the filtering material in the process of water purification from petroleum products. It was established that fibrous sorbents possess not worse characteristics than the commercial analogues do.

The plants of Filipendula ulmaria (L.) Maxim. growing in the Middle Urals can serve as a source of flavonols, catechins, tannins, saponins and carotenoids. A definite specificity in their accumulation in organs was established. The high carotenoid content in the leaves of Filipendula ulmaria was established by us for the first time.

Low molecular mass nitrogen bases inherent in highly resinous paraffinic oil species were studied. It is demonstrated that the structural-group composition thereof does not depend on the content of resin-asphaltene substances and paraffins in the oil and substances being characterized by a set of compounds typical for the bulk of the oil species produced.

An integrated set of problems connected with the features of calcium oxalate crystallization in the presence of amino acids is considered. It is established with the help of X-ray phase analysis that the formed precipitates are represented by calcium oxalate monohydrate (wavellite). The kinetic parameters of crystallization were determined. It was shown that the growth of crystals follows the mechanism of two-dimensional nucleation. It was established that amino acids have different effects on crystallization: glutamic acid, arginine, glycine, and lysine inhibit the process, while proline, serine, asparagine serve as the catalysts of the process; some amino acids (alanine, phenylalanine etc.) have insignificant effect on the kinetics of crystal growth. With an increase in supersaturation, the promoting action of amino acid weakens, while the inhibiting action enhances, which is connected with the competition of these effects.

Features of the thermal decomposition (pyrolysis, steam reforming) of carbon-containing raw material in the vibro-liquefied bed of inert material and in the presence of the catalysts of deep oxidation were studied. It was shown that the presence of catalysts in wood pyrolysis ensures more complete transformation of condensable organic substances (resins) into light gaseous products  (СО, Н₂, СО₂, СН₄). For a model oxygen-containing organic substrate (glycerol), it was shown that the conversion of glycerol during its steam reforming in pseudo-liquefied bed of the catalysts of deep oxidation follows several routes including gasification with the formation of СО, Н₂, СО₂ and СН₄, polycondensation of the products of glycerol dehydration with the formation of coke, steam gasification of coke. Similar processes are realized during the combustion of biomass at the stage of pyrolysis and gasification in the boiling bed. It was shown that efficient catalysts in the steam reforming of glycerol exhibit high activity in the process of oxidation of glycerol and biomass. Investigation of the process of catalytic combustion of aqueous solutions of glycerol showed that the degree of oxidation reaches 99.3–99.9 % with the use of the catalysts of deep oxidation. Oxidation process runs with the highest efficiency in the presence of PK–12–73 catalyst.

Using the technique of gas chromatography-mass spectrometry, essential oil composition was studied for species Agastache rugosa, A. scrophulariifolia, A. foeniculum, A. urticifolia, A. mexicana, cultivated under the conditions of the Middle Ural. It has been found that there prevail menthone (42.2 %) and isomenthone (18.8 %) therein.

A simple and environmentally safe method has been proposed for producing highly concentrated (about 0.01 mol/L) hydrosols containing copper nanoparticles with the size of 30–40 nm. The method is based on the reduction of Cu²⁺ ions in aqueous solution of ascorbic acid in the presence of high molecular mass gelatose stabilizer, the product of high temperature hydrolysis of gelatin.

The toxicity of the aqueous extracts from the sorption material containing the particles of nanostructured aluminium oxyhydroxide, modified with colloidal silver and non-modified ones, with respect to Daphnia and luminescent bacteria was studied. It was established that the toxicity of aqueous extracts is due to the presence of Al³⁺ ions migrating into water with low salt content, and oligodynamic action of silver.

Analysis was performed concerning heavy pyrolysis resin produced at the Tomskneftekhim Ltd and the products of  extraction and chromatographic separation thereof (oil species, resins and asphaltenes) with the use of a pyrolysis gas chromatography-mass spectrometry technique (PGCMS). Main structural fragments were determined for the resins and asphaltenes, as well as an individual composition was obtained for oils in the course of the decomposition thereof within a pyrolytic chamber at 800 °С in an inert atmosphere. It has been found that the oils represent a mixture of low molecular aromatic compounds such as condensed 3–6 ringed aromatic hydrocarbons the molecular mass up to 300 amu, whereas the resins and asphaltenes represent high molecular mass aromatic compounds, whose molecules are consist of 1–2-, 4–5- and 1–2-, 3–4-ringed aromatic fragments, respectively. Using the methods of PGHMS and IR spectroscopy, the composition of the high-boiling part of heavy pyrolysis resin has been identified.

A high temperature process of treatment by pinane hydroperoxide was studied for styrene-containing oligomer obtained from polybutadiene by-products. It is demonstrated that the oxidized product obtained could be used for the production of emulsion rubber, as well as for the protective treatment of wood and wood-ware.

The interaction of Al(III) with the anions of benzylpenicillin (Bzp^–) and carbenicillin (Carb^2–)in an aqueous solution at 25 °С and the ionic strength of 0.1 (KNO₃)solution was studied by means of the pH-metric titration. The formation of complexes AlBzp²⁺ (lg β = 3.6±0.1) and AlCarb⁺ (lg β = 4.10±0.08) in the slightly acidic medium was established.

The interaction of Al(III) with ampicillin (Amp^–) and amoxicillin (Axn^–) in an aqueous solution at 25 °С and the ionic strength of 0.1 (KNO₃) was studied by means of pH-metric titration. The formation of complexes AlAmp²⁺ (log β = 5.11±0.06), AlHAmp³⁺ (log β = 9.63±0.07), AlAxn²⁺ (log β = 4.64±0.09), AlHAxn³⁺(log β = 7.95±0.09) was detected.