|
Atmospheric aerosols of environmental pollution, climate change and human health has important implications, a large aerosol collection and analysis of the current research in the field of atmospheric environment is an important issue. Based on the principle of inertial impact of particulate matter sampler is now widely used aerosol sampling device, paper demonstrates the impact of the new multi-stage sampling with independent intellectual property rights, to achieve large aerosol particles according to particle size separation of the aerosol particles sampler , to complete 38 ~ 10,10 ~ 5.0,5.0 ~ 2.5,2.5 ~ 1.0,1.0 ~ 0.5,0.5 ~ 0.25,0.25 ~ 0.1μm particle size range of seven different simultaneous separation collection, and can provide a sufficient amount of, plane substantially uniform particle samples for subsequent physical and chemical analysis. The main contents focus on the impact of the new multi-stage sampling performance verification and analysis of large aerosol particles collected unfold. In briefly discusses the basic concepts of large aerosols, hazard, research trends and knowledge of aerodynamics, based on the discussion of a new type of multi-stage impactor working principle, structure, composition and calculation of their tiers nozzle design method . Reference to the relevant international and domestic impact sampler performance technical requirements, the use of uniform, monodisperse of 1.5 ~ 17μm particle aerodynamic criteria, the impact of new multi-stage sampling performance indicators validated by experiment, but with Andersen Corporation The eight impactor for aerosol mass collected comparative experiment results show that the new multi-stage impactor better able to realize the large aerosol particles separated by particle size class collection requirements. According to the requirements of 863 projects, respectively, in Chongqing, Ningbo and Beijing three cities using two sets of uniform flow of 10 l / min of the new multi-stage impactor for aerosol collection. Aerosol particles through quality, quantity, concentration analysis and calculation, combined with the national environmental authorities in the region given the period of time the air pollution index were compared and analyzed, and the three approximate distribution of aerosol particles. Using SEM and electron spectroscopy for Chongqing, Ningbo and Beijing three regional chemical composition of aerosol particles analysis, pointed out three areas of large regional differences in aerosol particles. And try to use high sensitivity TOF-SIMS surface analysis instruments carried on the part of the sample morphology analysis, surface positive and negative ion spectrum analysis and depth profiling analysis, given the large aerosol particles of inorganic and organic components analysis, in-depth study large aerosol provides a more reliable basis.
|