METHOD TO DETERMINE COEFFICIENT OF VERTICAL DIFFUSION OF EMISSIONS OF INDUSTRIAL ENTERPRISES IN ATMOSPHERIC BOUNDARY LAYER Russian patent published in 2015 - IPC G01N23/222 G01N21/62 

FIELD: measurement equipment.

SUBSTANCE: invention relates to the field of research or analysis of materials, namely, to determination of coefficient of vertical diffusion of emissions of industrial enterprises in atmospheric boundary layer with the help of neutron-activation analysis. The method consists in the fact that in the specified direction from an industrial enterprise at different distances from 1 to 5 km they take at least 5 samples of epiphytic moss Pylaisia polyantha (Hedw.) B.S.G. from bark of birches, aspens and poplars at the height from 1.5 to 2 m. Besides, one sample is selected on a background territory with natural-climatic conditions, identical with the researched territory, and located at the distance of more than 100 km from industrial centres in direction opposite to the preferential wind rose. Moss samples are cleaned from foreign admixtures, washed with distilled water, dried at temperature from 80 to 100°C, homogenized, and from 5 to 10 parallel representative samples are made. When using neutron-activation analysis, samples are exposed to radiation with a flux of thermal neutrons for 5 hours. After reduction of activities of Na²⁴ to safe level they determine specific activity of each sample by comparison of intensity of gamma lines of radio nuclides of chemical elements in a sample with intensity of gamma lines of standards. Values of concentrations of chemical elements in moss samples determined with the help of neutron-activation method, by the method of least squares are approximated by the dependence of the following type: where q _b - background (natural) concentration of the chemical element in the sample chosen in the territory located at the distance from industrial enterprises from at least 100 km; x - distance from points of moss sampling to the industrial enterprise, determining at the same time numerical values of coefficients A, C and θ, then they calculate the coefficient of proportionality of vertical diffusion k₁: where n - dimensionless parameter for interpolation of vertical profile of wind speed: u(z)=u₁zⁿ, where u₁ - average annual speed of wind at height of 1 m; H - height of an industrial enterprise stack, and use it to determine coefficient of vertical diffusion of emissions of industrial enterprises in atmospheric boundary layer according to the following formula: k_z=k₁z, where k₁ - coefficient of proportionality of vertical diffusion; z - height from earth surface.

EFFECT: invention provides for the possibility to use for any area regardless of its relief and with account of atmospheric conditions realised during exposure time.

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