Лазерный контроль среднего объемно-поверхностного диаметра частиц для оценки параметров аэрозольного загрязнения атмосферы

Abstract

Aerosol air pollution is one of the most dynamic factors of the environmenal technogenic transformation. The danger degree of the aerosol particles increases in air with their sizes reduction therefore the dust disperse composition has the great hygienic value and in the working zone air and the dust disperse composition at the enterprise border — on health of the population of these territories are the important characteristic for its It has led to the introduction of new ecological standards for mass concentration of the particles with a diameter less than 10 μ (PM10) and particles with a diameter less than 2,5 μ (PM2,5). impact assessment on health of the enterprise employees and the population of near territories. The laser methods using for the assessment of parameters of aerosol emissions and extent of their impact on the environment have been introduced in this article. The modified spectral transparency method is the best of all and suitable for determination of the average size and concentration of disperse particles. The physical model of this method is based on interaction of monochromatic laser radiation with the polydisperse aerosol by Mie’s theories and maintaining invariancy of the average factor of the extinction efficiency concerning the type of the of particles size distribution function with using of the concept of particles average volume and superficial diameter. The optical density measurement of the disperse aerosol is performed at the same time, on several wavelengths, and the average factors of the extinction efficiency for these laser radiation wavelengths can be derived from the experimental data. This method has rather simple hardware realization and allow to diagnose flows of high optical density (that is characteristic of technogenic aero disperse flows).