西宁市典型开放源颗粒物粒径组成特征分析

Analysis on Particle Size Distribution of Typical Open-Sources in Xining

采用BT-9300S激光粒度仪分析了西宁市道路尘、扬尘、土壤尘、建筑尘4种典型开放源的粒径组成。结果表明,4种类型尘中大粒径颗粒物占主导地位,粒径大于10μm颗粒占到全部颗粒的73.80%以上,可吸入颗粒物的含量仅占7.06%～26.20%;建筑尘的细颗粒物含量最高,粒径小于2.5、1μm的颗粒含量分别为8.36%±4.25%、2.42%±1.02%;道路尘的细颗粒物含量最低,粒径小于2.5、1μm的颗粒含量分别为2.30%±0.94%、0.73%±0.28%;4种类型尘的体积平均直径、面积平均直径、中位直径分别在37.70～87.99μm、8.50～23.53μm、28.95～74.98μm之间,其中道路尘的3种粒径参数最大,建筑尘最小;开放源颗粒物的粒度分布曲线主要呈头长尾短的不对称单峰分布,累积频率曲线为两段式,存在较为明显的拐点。

The particle size distribution of four typical open-sources in Xining was analyzed by BT-9300S Laser Grain Size Analyzer. Results showed that particles of the road dust, re-suspended dust, soil dust and construction dust in Xining city were rich in coarse fractions, accounting for more than 73.80% fur particles with diameters〉10 μm, while inhalable particle occupied by 7.06% - 26.20%. Fine particles were most abundant for construction dust with diameter〈2. 5 txm and 〈 1 μm accounting for 8.36%±4.25% and 2. 42% ± 1.02% , respectively while fine particles in road dust less than 2.5 μm and 1 μm only accounted for 2.30% ± 0.94% and 0. 73% ± 0.28% , respectively. Volume average diameter, surface area average diameter and volume median diameter were in the ranges of 37.70 - 87.99 μm, 8.50 - 23.53 μm, 28.95 - 74.98 μm, respectively. The particle size distribution curve for the four open sources is asymmetric distribution and the cumulative frequency curves exhibited two-stage shape with obvious turning points.