Home – Home – Jornals – Chemistry for Sustainable Development 2002 number 5

The problem of acid deposition in West Siberia is discussed on the basis of the data on the ion composition of atmospheric aerosol, precipitation and surface waters, obtained for different natural climatic zones (from the tundra in the north to the steppe in the south) in 1996

Results of 3 year-long studies of the biogenic component of the atmospheric aerosol in the south of West Siberia using terrestrial measurements and aircraft monitoring of the atmosphere and analysis of collected snow cover samples are presented. The seasonal dynamics of the content of components of this biogenic component has been obtained, their possible local and remote sources have been determined. It has been demonstrated that maximal and minimal values of concentration of total protein in the atmosphere differ by about an order, and the concentration of microorganisms does so by more than 2 orders. At the same time, the found values are quite consistent with literature data for other regions. On the basis of the data obtained, it is hypothesized that the main contribution to the biogenic component of the atmospheric aerosol even during the spring-summer period is made not by local, but by remote sources of bio-aerosols. Mathematical models are proposed which permit making definite conclusions about the localization of these sources. It is demonstrated that the greatest influence on this region is exerted by the sources situated in Middle Asia and North-West Kazakhstan.

On the basis of the known theoretical developments, a sufficiently simple model of local scale has been built and software-supported, which uses as the input information the normative databases on industrial sources and accessible climatic information. Bibliographic sources and general principles of model construction are considered, and the calculation results are compared with data of experimental studies of some industrial objects and cities of the Kemerovo Region.

Experimental data on annual variability of 7

The results of investigation of the interaction of halogen-containing organic compoungs (HOCs) with magnesium, aluminium and silicon oxides of industrial and laboratory preparation in the dark and under the action of sunlight in the troposphere are presented. The chemical composition of these oxides corresponds to the main components of solid atmospheric aerosol. The experimental results are the evidence that fluorine- and chlorine-containing organic compounds containing also hydrogen atoms are destructively photosorbed on MgO exposed for a long time in the air, magnesium halides being formed as a result of photosorption. The rate of photosorption for fluorine-containing hydrocarbons is several times higher than that for chlorine-containing hydrocarbons. The amount of hydrochlorofluorocarbons (HCFCs) photosorbed at room temperature and pressure of 1 Pa can exceed 15 % of the monolayers of MgO surface. The interaction of magnesium oxide with HCFCs leads to their removal from the atmospheric air under tropospheric conditions till the residual HCFC pressure less than 10

The elemental and phase composition of the surface layers of atmospheric aerosol (AA) particles sampled in winter 1998 in Irkutsk, Listvyanka and Ulan-Ude, is investigated by means of secondary ion mass spectrometry. It is stated that the source of AA is erosion of aluminosilicate soil. The surface of AA particles is covered by adsorbed hydrocarbons, nitrogen-containing compounds and partially by organic particles with a size of about 30 nm.

A brief review of works on the development of the system of mathematical modeling of processes in the atmosphere and on the assimilation of the data of meteorological observations is given. In addition, the works on the applicability of the Kalman filter theory to the problem of the assimilation of observation data are reviewed.

The spectra of aerosol samples collected near the Lake Baikal are investigated with the help of synchrotron radiation (SR). It is demonstrated that it is possible to determine the phase composition of real atmospheric aerosol and the oxidation degree of 3d-elements in them by means of XANES and X-ray diffraction using SR.

A method is proposed for the determination of the emission rate of various components by industrial enterprises using the data on spatial-temporal variability of the concentrations of chemical elements or compounds in observation sites remote from sources.

A semi-empirical model is proposed for the description of seasonal changeability of the diurnal variations of the accumulation mode of continental atmospheric aerosol of remote territories. The data of synchronous measurements of diurnal variations of the mass concentration of accumulation mode of AA in winter and in summer are reported, obtained in two observation sites in the Novosibirsk Region, the distance between them being 450 km. Results of calculations according to the theoretical model are in good agreement with the experimental data.

Thermodynamic models of extremal intermediate states (MEIS) are used to describe the features of the formation of nucleating drops and aerosol watering in the atmosphere. Advantages of MEIS in describing phase transitions in multi-component systems are shown. Results of the calculation of the equilibrium (thermodynamically most probable) drop radius are discussed for different ratios of the soluble to insoluble components of the condensation nuclei. The proposed approach allows numerical investigation of the effect of meteorological conditions on microphysical characteristics of haze, clouds and fog. Theoretical substantiation of size distribution of the aerosol of different origin will allow estimating possible anthropogenic effect on optical characteristics of the atmosphere, which are one of the basic climate-forming factors.

Reference-free method of differential dissolution (DD) is used to obtain the data on stoichiometric composition and content of solid phases, including those of variable composition, in the samples of multi-element multiphase atmospheric aerosols. In aerosol sample collected in one of the regions of Novosibirsk, the content of water-soluble fractions (presumably hydrosulphites) of a series of metals was determined, as well as the content of individual calcium phase (presumably carbonate), calcium sulphate phase, and two aluminosilicate phases. In these phases, formed by the major elements comprising aerosol (Si, S, Al, Fe, Mg, Ca, K, Na), the content of a series of admixture elements was determined. For the alkaline-earth elements as example (Mg, Ca, Sr, and Ba), the ratios of these elements was determined in the phases formed by the major elements Mg and Ca, and by microelements Sr and Ba. It is concluded that the possibility to obtain detailed quantitative data on the phase composition of aerosols is essentially important in investigating various aspects linked both with the mechanisms of formation and evolution of atmospheric aerosols and with their effect on the status of environment.

On the basis of analysis of calculations by a hydrodynamic model of atmospheric convective ensemble (LES), various mechanisms of cloud and precipitation formation processes are discussed. The influence of convection on the vertical transportation of aerosols has been studied. Advantages of LES in application to theoretical studies of vertical transport of aerosols in the atmosphere are demonstrated.

Methodical problems and results of analysis of influence of atmosphere pollution on forest-swamp complexes of the taiga zone of West Siberia are considered on the example of emissions of ecologically harmful chemical compounds released during combustion of casing head gas in torches installed in the territory of petroleum-gas deposits. The analysis was carried out using a comprehensive approach based on combination of the sanitary-hygienic and landscape-geochemical methods. A quantitative estimate of the dimensions of the area of landscape units contaminated with discharges of soot and nitrogen dioxide into the atmosphere, depending on the burning gas volume and on the threshold level of atmosphere pollution, is given. The studies were carried out using the data on air contamination obtained on the basis of ecological certificates of petroleum deposits in the oil production territory.

A survey of experimental and theoretical methods of the investigation of aerosol pollution of snow cover in the vicinity of man-made sources is performed. On the basis of the formulation of inverse problems of the transport of admixtures in the surface and boundary layers of the atmosphere, a description of the models for the recovery of aerosol precipitation fields for the sources of different types is presented. The results of tests with man-made sources of West and East Siberia are reported. The use of the methods of consequent analysis of the data of monitoring and planning of snow surveys is discussed. The models of optimal decrease in emission from the set of sources are discussed.

A model of long-term pollution of environment by motor transport emission is proposed. The numerical model was tested for the recovery of long-term aerosol pollution of the locality by polycyclic aromatic hydrocarbons, lead, macro-components; the data of strip snow surveys near the Barnaul motorway and the Sovetskoye highway in Novosibirsk are involved. The structural changes of aerosol emission of motor transport during winter seasons of 1998

The major results of investigation of the arsenic pollution of snow cover near the Novosibirsk Tin Plant at the end of winter seasons of the years 1994

Data of 3-year-long observations of the chemical composition of precipitation, aerosol, soils and surface waters at three monitoring stations in the Baikal region are presented. The choice of observation objects is substantiated. Problems of natural objects" resistance to acidification are considered. The resistance of terrestrial ecosystems to acidification has been estimated quantitatively, and that of surface waters has been done so qualitatively. It has been demonstrated that symptoms of acidification are manifested most strongly in regions lee with respect to regional industrial centres at a distance of several tens and hundreds kilometres from them. The permissible acidity load for the soils of the territory under consideration varies from 1.25 to 1.4 keq/ (ha yr), while the maximal modern acidity load attains only 0.4 keq/ (ha yr).