Morphological Analysis And Calculation On The Light Scattering Properties Of Soot Aggregates In Atmospheric Aerosol

The solid and liquid particles suspended in the atmosphere are collectively referred to as atmospheric aerosols.Carbon black aerosols are one of the main constituents of atmospheric aerosols,mainly from the incomplete combustion of fossil fuels.Carbon black aggregates not only harm the human respiratory system,and endangering human health and safety,causing haze phenomenon,duing to its absorption and scattering of solar radiation.It will also lead to ambient temperatures rising,increasing global warming.The carbon black aerosol scattering light contains the composition,structure and other related information,it can also be used to distinguish the size of aggregates to different fog,haze,carbon black aerosol light scattering characteristics of the calculation and analysis of air pollution control,it has a vital role to maintenance environmental safety.The structure of the carbon black aerosol in the atmosphere is complex and random,and its light scattering characteristics are affected by many factors.Generally,the light scattering characteristics of the carbon black aerosol are analyzed by experimental measurement and theoretical calculation.The calculation of the light scattering characteristics of the carbon black aerosol is established in this paper.The specific research contents are as follows: The samples were analyzed by scanning electron microscopy(FEI quanta 200F),and the images were collected by image processing software IMAGEJ to extract the carbon black agglomerate geometry.The microstructure of the carbon black aggregates was analyzed by scanning electron microscopy(FEI quanta 200F)(Particle number,fractal dimension,forward factor).Based on the CCA model and the T-matrix model,the light scattering of carbon black aggregates under different incident wavelengths,particle numbers,fractal dimensions and forward factors was simulated by light scattering.Based on the light scattering method,the calculation model of extinction,scattering and absorptioncoefficient with the number of particles is established.The carbon black suspension with the concentration of 0.05g/100 ml is set up,and the carbon black aerosol is used.The extinction coefficient was calculated by the model and the transmittance spectrum of the suspension was measured by spectrophotometer.The extinction coefficient of the carbon black aggregate was calculated and the calculation model of the extinction coefficient was corrected.