Home – Home – Jornals – Chemistry for Sustainable Development 2012 number 6

Modern analytical methods of the investigation of platinum-containing objects are considered, including the features and possibilities of the combined methods to determine trace amounts of platinum and palladium in surface water, soil and rocks. The data on metal content, the forms of their occurrence in geochemical systems and in technogenic sources from which they inter the environment are reported. The migration behaviour of different forms of platinum and palladium under the conditions characteristic of natural systems are considered, along with the results of model studies of the sorption behaviour of these elements at geochemical barriers.

The development of catalytic methods for the oxidation of organic compounds those fit contemporary environmental requirements represents a complicated and highly urgent task, especially for the processes of fine and pharmaceutical chemistry. This review summarizes data concerning the catalytic oxidation methods developed during the last 20 years for converting 2,3,6-trimethylphenol into 2,3,5-trimethyl-1,4-benzoquinone, a key intermediate for the synthesis of vitamin E. Also considered catalysts during 2,3,6-trimethylphenol hydroxylation in to 2,3,5-trimethyl-1,4-hydroquinone are considered, too.

Preliminary birch bark activation by steam under the conditions of explosive autohydrolysis was studied. It has been established that as the result of the preliminary processing the sorption activity of obtained enterosorbents with respect to methylene blue and gelatin exhibits a significant increase. The properties of enterosorbents resulted from autohydrolyzedyh phloem and silver birch bark have been compared. Conditions for the activation of birch bark by explosive authohydrolysis to obtain enterosorbents have been determined those could be better than commercial enterosorbent Polyphepan according to the sorption activity with respect to methylene blue and gelatin.

The content of biologically active substances (flavonols, catechins, tannins, carotenoids) was studied for 45 samples of amaranth (Amaranthus L.) of different geographical origin, grown at the experimental plot of the Institute of Cytology and Genetics of the SB RAS (Novosibirsk). Amaranth leaves contain up to 3.2 % of flavonols, 0.33 % of catechins, 10.7 % of tannins, 101.4 mg% of carotenoids, whereas the flowers contain up to 3.1, 0.19, 11.3 %, and 32.3 mg %, respectively. A significant variation in the characteristics under testing has been revealed, which allows one to carry out the selection for increasing the content of either substance, and to use available species as feedstock sources.

By means of reducing or thermal cracking, spent sulphur-containing sorbents obtained from waste organochlorine products can be converted into valuable organosulphur products such as 1,2-dithiol-3-thione, or 1,2,3-tris(methylsulphanyl)propane. The metal contained in the sorbent in both cases is transformed into corresponding sulphide and could be used to produce the metal in the usual way.

Kinetics of propylene epoxidation using an aqueous solution of hydrogen peroxide in the presence of titanium-containing zeolite was studied. An effect of concentration reagent and reaction product concentration and the temperature on the reaction rate was considered. Basing on the experimental data obtained, a mathematical model of the process was proposed to calculate the reaction rate constants, adsorption equilibrium and activation energy.

Mechanochemical synthesis of titanium and tungsten carbides involving carbon modifications obtained from the wastes of agricultural plants was developed. The conditions that affect the progress of mechanochemical synthesis of tungsten and titanium carbides were studied.

Processes were studied concerning uranium extraction from the mineralized water of the Shaazgay Nuur Lake using the techniques of galvanochemistry and ion exchange on anionites. The application of galvanochemical method with the use of coal and steel wool as galvanic couple has been demonstrated to allow almost completely extracting the uranium from the mineralized water with the uranium content amounting to about 1 mg/L. A quantitative extraction of uranium from the mineralized water using anion exchangers AM-P, Purolite A-400 and Purolite A-560, has been shown to be possible, both in static and dynamic modes.

A new efficient preparation with the broad range of action was developed on the basis of the aqueous solution of larch extract with the addition of a salt of 2,4-dichlorophenoxyacetic acid with bisamine and the extract of lichens of Usnea genus. The activity of this preparation is comparable with that of chemical fungicides. The preparation suppresses the development of mycosis and increases the productivity of spring wheat.

Cellulose derivatives were synthesized containing up to 25 mass % of the fragments of ferulic or vanillic acid. Phenol-containing polysaccharides obtained by means of intermolecular nucleophilic substitution reaction between 6-chloro-6-deoxy cellulose and potassium or tetrabutylammonium salts of corresponding phenolic acids. The source halogenated deoxy polysaccharide was obtained via the action of sulphuryl chloride on cellulose in the presence of pyridine in N,N-dimethylformamide environment.

Urgency is demonstrated concerning the studies focused on the development of processes for producing a new generation of environmentally safe and biodegradable polymeric materials. Basing on the experimental characteristics of the process of synthesizing polyhydroxyalkanoates obtained as the result of pilot plant operation at the Institute of Biophysics of the SB RAS (Krasnoyarsk), there has been a technical and economic analysis of the process performed. Calculation results are presented for the cost price of polyhydroxyalkanoates in the case of different substrate scenarios.

Via the selective oxidative transformations of double bonds in (+)-(3S)-3,7-dimethylocta-1,6-diene (dihydromyrcene), the main thermolysis product of (+)-cis-pinane, efficient schemes are developed for the synthesis of a number of optically active insect pheromones.

Nanofibrous carbon (multi-wall nanotubes) was obtained through mechanochemical treatment of the amorphous modification of carbon, synthesized from sphagnum moss, carried out using the vario-planetary mill.

A predominant role of volcanic factor in strengthening the springtime ozone anomalies over Antarctica has been demonstrated. Correlation analysis was performed concerning the average data for September and October with respect to the areas of polar stratospheric clouds and the ozone hole over Antarctica as well as with respect to minimum temperature values in the stratosphere at an altitude of 18 km, during three 11-year period from 1979 to 2011. It is demonstrated that the accelerated growth of the ozone hole in the early 1980s coincided with the maximum gas emissions of the Antarctic volcano Mount Erebus. Within the subsequent 11-year period, increasing the area of the ozone hole was caused by an abrupt increase in the content of sulphuric acid aerosol in the stratosphere over Antarctica associated with powerful volcanic eruptions of Mount Pinatubo and Hudson Cerro in 1991.