Pollution character of PM_(2.5) water-soluble organic compounds in Beijing City
YU Xue-chun, HE Ke-bin, MA Yong-liang, DUAN Feng-kui, YANG Fu-mo (Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China). China Environmental Science, 2004,24(1):53~57
The pollution levels of 12 kinds of inorganic ions (F-, Cl-, NO2-, NO3-, SO32-, SO42-, PO43-, Na+, NH4+, K+, Mg2+, Ca2+) and 7 kinds of WSOC (formate, acetate, methylsulfonate, oxalate, malonate, succinate, glutarate) in atmospheric PM2.5 of Beijing City in the year 2001~2002 were determined synchronously with ion chromatography (IC) technique. SO42-, NO3- and NH4+ were the dominant water-soluble species occuping 10.6%, 7.4% and 5.7% of PM2.5 mass respectively. The concentrations of 7 kinds of WSOC were 0.011~0.118mg/m3 occupying 0.01%~0.1% of PM2.5 mass concentration, among which oxalate was the highest and acetate, succinate, malonate and formate were the next. Analysis of seasonal change character of the concentration of each chemical component of PM2.5 indicated that high concentrations pollution of PM2.5 and OC appeared in winter (during heating period) and that of WSOC was in summer. Analysis of interrelativity of oxalate with other component showed that oxalate had relatively high linear interrelativity with SO42- (r=0.83), K+ (r=0.57), NH4+ (r=0.49) and NO3- (r=0.33), while had relatively poor with Cl- (r=0.24), Na+ (r=0.22), Mg2+ (r=0.12), Ca2+(r=0.05), EC (r=0.13) and OC (r=0.10). Preliminary deduction was made from the characters of oxalate change and the interrelativity with other species that the main source of PM2.5 dicarboxylic acids in Beijing City was the secondary pollutants produced by the photochemical reaction, not the primary pollutants released from vehicles, sea-salts or soil.
【CateGory Index】： X51