|
|
Home – Home – Jornals – Chemistry for Sustainable Development 2007 number 3
2007 year, number 3
O. Y. Krasnoslobodtseva, S. M. Salikhov, B. T sharipov, F. A. Valeev, G. A. Tolstikov
Pages: 269-289
Abstract >>
Sources, methods of isolation, structure and properties of diterpenoids of eunicellane series produced by sea organisms are considered. The schemes of complete synthesis of the urocanates of diterpenoids of 4,7-oxaeunicellane type possessing unique cytotoxic effect are discussed. The known routes of establishing the interconnections between structure and activity in the sarcodictyine series are presented.
|
E. V. Malykhin, T. A. Vaganova, T. P. Kukina, S. A. Popov, A. M. Chibiryaev
Pages: 291-308
Abstract >>
The review systematizes the data from scientific publications, patents and Internet resources about the consumer products (preparations) made of the wood green of abies, their biological activity and areas of application. The group chemical composition of extractives from the tree green of abies and the technologies of obtaining them are characterized.
|
T. G. Tolstikova, G. G. Furin, M. P. Dolgikh, A. A. Il'in
Pages: 309-316
Abstract >>
Primary toxicological parameters of fluorine-containing alcohols, dialkyl ethers, acetales, acrylates, esters of carboxylic and dicarboxylic aliphatic acids, epoxides and olefins used as the materials and intermediate products of organofluoric synthesis are considered. The regularities of the effect of fluorine atoms on the toxicity of the compounds are revealed. All the investigated compounds belong to the III and IV class of danger and are safe for developing fluorinated materials on their basis. Some examples of the application of these classes of compounds are discussed.
|
A. G. Belobaba, A. I. Masliy, D. V. Sukhorukov, Li Gan
Pages: 317-322
Abstract >>
Dependence of the processes involving reduction of the main components of fixing solutions (silver ions, thiosulphate and sulphite) on silver, graphite and platinum cathodes on pH is investigated. It is established that the pH value has the strongest effect on the reduction of sulphite ion; in the medium with рН ≥ 7 it does not get reduced. Quite contrary, the reduction of thiosulphate and silver is only weakly dependent on this parameter. The optimal electrolysis conditions (potentiostatic mode at the cathode potential equal to 0.85 V, and рН ≥ 7) were chosen so that they allow one to recover the worked out fixing solutions using the flow voluminous porous cathodes and to decrease the residual silver content down to 0.5-1.0 mg/l.
|
E. I. Biryukova, S. V. Amosova, L. P. Shaulina, I. P. Golentovskaya, G. V. Ratovskiy, S. A. Zhivetyeva, E. V. Likhoshvay
Pages: 323-328
Abstract >>
Moulded copolymers of styrene with divinylsulphide were synthesized by means of the living radical polymerisation with N,Nґ-bis(vinyloxyethyl)thiuramdisulphite as an initiator without any solvents. It was shown that the formation of a polymeric body proceeds without the formation of a macrogel. Individual particles of copolymers were discovered using scanning electron microscopy. These particles are monospheroids with a size about 1 μm; they determine further formation of the moulded polymeric body as granules. Copolymer modification was carried out, ionites were obtained. The effect of the nature and concentration of acids on the extraction of silver, gold and platinum ions was established. High distribution coefficients equal to (2.0-6.5) 104 were obtained for the chloride complexes of gold and platinum. The possibility to use sorbents for concentrating precious metals and for analytical purposes was demonstrated. A method of sorbent regeneration was developed.
|
T. N. Volgina, V. T. Novikov
Pages: 329-331
Abstract >>
It was established that deep oxidation of such toxic strong compounds as organometallic pesticides occurs under the action of the system formed by passing the electric current through aqueous solutions of sulphuric acid. On the basis of experimental data, multiparametric equations characterizing the effect of the current density, temperature, concentration of sulphuric acid on the rate of oxidation of the organic fragments of pesticides and metal ion reduction on the cathode were obtained.
|
O. L. Gaskova, S. B. Bortnikova, G. P. Shironosova
Pages: 333-346
Abstract >>
Thermodynamic model of the oxidative leaching of sulphide-rich tailings from dressing of gold-containing ores (Berikul settlement, West Siberia) is investigated. When calculating the water - rock interactions, we applied some special approaches allowing one to determine the effect of the degree of reaction progress and change of the parameters of the medium (Eh, pH) on the composition of the formed secondary minerals that restrain the development of acid drainage at the objects of this kind. Substantiation of several stages of the formation of a technogenic system in time and space is presented, depicting the approach of the system to equilibrium with the environment. The distinguished stages correspond to the zoning of mineral associations described at the object. These associations were formed during 50 years of storing the tailing mounds from the lowest weakly oxidized sulphide parageneses with gypsum and covellite to the capping jarosite-quartz-gypsum zones. The results of modelling provide evidence that an increase in rock affection by atmospheric water brings about the conditions favourable for the formation of the "final" association (goethite and quartz); however, this association is not stable even on the surface of the Berikul tailing dump. It is concluded on the basis of preliminary evaluation that hypergenesis processes in the objects of this kind may proceed hundreds of years till complete depletion of the acid-producing and toxic potential of industry-related wastes.
|
N. M. Kozhevnikova, N. L. Tsybikova
Pages: 347-350
Abstract >>
Processes of neodymium sorption from the solutions of neodymium sulphate on the natural clinoptilolite tuff were studied, and the sorption isotherms of neodymium ions were obtained. It was found that neodymium is extracted quantitatively from the dilute solutions (<0.0025 mol/l), but the exchange capacity of tuff in respect to neodymium ions decreases with increasing solution concentration. Kinetic parameters of sorption process were determined.
|
T. A. Mikhailova, O. V. Shergina, N. S. Berezhnaya
Pages: 351-358
Abstract >>
Sulphur content in the system woody plants-forest litter-soil (the profile-genetic level) was investigated within the boundaries of the urban territory. High accumulation of total sulphur in the needles and leaves of tree species was demonstrated. A substantial depositing ability of the forest litter, upper organics-accumulating and texture horizons of urban soil with respect to the industry-caused sulphur compounds was discovered. A close connection between the sulphur content of tree needles (leaves) and forest litter, as well as the soil profile, was revealed. It was demonstrated that sulphur accumulation in assimilation organs of plants and its physicochemical redistribution in the soil profile might serve as the ground for the adequate evaluation of the degree of industrial load on an urban ecosystem.
|
V. A. Titov, L. I. Chernyavskiy, L. A. Borisova, B. A. Shagarov, S. A. Muravitskiy, V. N. Nitkin, V. A. Postnikov
Pages: 359-362
Abstract >>
The problem of gaseous hydrogen-hydrogen chloride mixture separation with the use of chlorosilanes as sorbents is considered. The possibility of hydrogen purification from HCl up to 0.1 mol. % and its re-entry into the process cycle at the stage of trichlorosilane reduction with hydrogen is demonstrated. The hydrogen chloride purified from admixed chlorosilanes can be used as a reactant for the trichlorosilane production from metallurgical silicon.
|
A. A. Nikonova, A. G. Gorshkov
Pages: 363-369
Abstract >>
Concentrations of polychlorinated diphenyls (PCD) were measured in snow cover (10-520 ng/m2), in the soil (0.3-45 ng/g of dry mass) of Pribaikalia and the southern lakeside, in bottom sediments of Lake Baikal and its tributaries (0.3-3.9 ng/g of dry mass), in Baikalian omul (Coregonus autumnalis migratorious G., 25-41 ng/kg of damp mass). A conclusion concerning the background pollution of the atmosphere of Pribaikalia with PCD at present and the absence of intensive local sources of organic pollutants of this class at this territory is formulated. The concentrations of PCD in soil and bottom sediments remained almost unchanged during the years 1992-2006. The levels of PCD bioaccumulation in Baikalian omul are 3.5-10 times lower than the MPC. Determination of PCD was carried out with the help of gas chromatography-mass spectrometry with the intra-laboratory precision of 7-15 %.
|
V. R. Khusnutdinov, V. P. Isupov
Pages: 371-376
Abstract >>
Samples of layered double Mg-Al hydroxides with different Mg/Al ratios were obtained by means of the mechanical activation of the mixture xMg(OH)2 + yAlCl3 · 6H2O with the x/y reagents ratio equal to 3/1, 4/1, 5/1 and 6/1 in a planetary mill AGO-2. It was shown that activation for 25 min with additional mixing and activation for 10 min in the presence of an inert additive KCl allows one to obtain layered double Mg-Al hydroxides without admixtures of initial reagents.
|
Y. V. Rokosov
Pages: 377-382
Abstract >>
Outlooks for carrying out problem-oriented prospecting investigations and for building up the scientific and technical basis in the area of the efficient use of sapropelite raw material resources.
|
|