On-line Analysis and Mass Concentration Characters of Nitrate in Aerosol PM10 in Beijing

摘要

Nitrate is one of the most important components in water-soluble aerosols. The nitrate in PM10 measured from January 2004 to December 2005 in Beijing was determined using a system of combining rapid collection of fine particles and Ion Chromatography (RCFP-IC). The scientific research showed that the annual average concentration of water-soluble nitrate in PM10 in the urban area in Beijing was about 9.2 (10.5±5.3) μg·m-3 in 2004 and 8.9 (7.7±3.0) μg·m-3 in 2005 respectively. The concentration of nitrate in summer and autumn was higher than that in spring and winter. Trends of the statistics diurnal variation of nitrate showed different in different seasons. In summer, the higher concentration appeared at forenoon and the lower appeared in the afternoon. While in winter, the higher concentration appeared in the afternoon and the lower appeared at forenoon. In summer and autumn, the diurnal variation of nitrate was different in 2004 and 2005. The typical diurnal variations of nitrate was analyzed in this paper, such as heating period and non-heating period, sunny day and rainy day, less polluted period and more polluted period. The relationship of nitrate and meteorological factors can be investigated using correlation analysis.