Concentration Variation and Morphological Types of PM2.5 in Suburban of Yinchuan City

PM2.5 samples were collected by Desktop Aerosol Monitor Models 8530 and recorded the meteorological conditions in study site of Yinchuan City simultaneously. The daily averages of PM2.5 mass concentration varied from 0.134 to 0.222mg m3. The result shows that there are two apparent peaks of PM2.5 concentration in one day. Normally,PM2.5 mass concentration and temperature have some negative correlation. Their morphologies were determined by scanning electron microscopy (SEM). The particles were classified into four groups based on morphology. They were fly ash, mineral matter, irregular shaped mineral particle aggregation and other types. Fly ash and mineral matter were the two dominant types and fly ash is identified as originating from coal combustion or metallurgical plants, mineral matter from natural sources such as soil dust, resuspension of dust from roads.