Analysis Of Atmospheric Particulate Matter Pollution And The ²¹⁰Pb Concentration-Particle Size

The significance, current status and methodology of the research on particle concentration of the atmospheric particulate matters with different classes and the radioactivity of 210 Pb in the atmospheric particulate matters with different particle sizes are systematically studied in this dissertation. The radioactivity of 210 Pb in the atmospheric particulate matters with different particle sizes were measured by using?counting method and ?spectroscopy method as a part that the research focused on, and the stability of the results measured by two methods were compared and analyzed. Meanwhile, the experiment model, as well as the scheme for particle collection, treatment and measurement were designed and set up. The impact of high flow particulate collector were employed to collect the atmospheric particles with different particle sizes in Hengyang, Shanghai and Lhasa, and the concentration of the particles were monitored by ELPI during the collection period. Treatment with digestion good sample collection, sample digestion, separation,concentration and volume and other treatment. The radioactivity of 210 Pbin the atmospheric particulate matters with different particle sizes were measured by MPC-9604-type ?/? low background counter and GR8023-type high-purity germanium(HPGe) ? spectrometer and the numerical analysis were carried out.The research determined the technical routine, methodology and plan of the experiments. Electrostatic low pressure impactor(ELPI)?M235 The impact of high flow particulate sampler?MPC-9604-type ?/?low background counter and GR8023-type high-purity germanium(HPGe) ? spectrometer were employed to collect and measure the particle concentration of the atmospheric particulate matters with different classes and particle sizes. The 210 Pb specific radioactivity in the total suspended particulate in the air of Hengyang is 1.6614~4.4752mBq·m-3 with mean value 3.2848 mBq·m-3. While in Shanghai, the mean is 0.3108 mBq·m-3in summer and 1.3656 mBq·m-3 in winter. In Lhasa, the mean is 0.6278mBq·m-3 in summer. The maximum of the specific activities in Hengyang and Shanghai are in the range between 0.49 ~ 0.95?m,occupying 39% and 62% in the total suspended particulate respectively.In Lhasa, specific activities maximum is below 0.95?m up to 47% in the total suspended particulate.The radioactivity and its consistency for atmospheric particular samples were measured and analyzed by?counting method and?spectroscopy method in this experiment. The results show that the?counting method has better stability for measurement the particles with size less than 1.5?m while?spectroscopy method is more stable for measuring the particles with size greater than 1.5?m. For the results of TSP, ?counting method shows better stability.