Pollution Characteristics Of Inhalable Particulates In Hefei City

Inhalable particulate matter (PM10) is the major component of atmospheric particulates. After having taken samples of PM10 in four districts in Hefei during all seasons, this thesis attempted to analyze features of PM10 pollution in Hefei and make determination as well as analysis of inorganic elements,organic carbon,elemental carbon, soluble ions and polycyclic aromatic hydrocarbon contained in the particulate matter during spring and summer. Conclusions of this thesis are as following:(1) The highest PM10 concentrations in the main urban area of Hefei city during the all seasons for sampling were respectively 11.855μg/m、80.740μg/m、110.19 μg/m3、135.19μg/m3, The order of concentration from high to low was winter>spring>autumn>summer. According to analysis of inorganic elements during the sampling period, terrestrial elements Si, Ca, Al, Fe and Mg were of relatively high concentration, and the pollution element S was also of relatively high concentration.The order of concentration from high to low was Si>Ca>Al>Mg>S>Fe>K>Na>Zn>Ti>Ba>Mn>Pb. The enrichment factor coefficient of pollution element Ca was 15.086,indicating remarkable enrichment.(2) In terms of OC concentration during the sampling period in spring and summer,districts in the main urban area of Hefei city could be ordered as Yaohai district>Baohe district> High-tech district>Luyang district. In terms of EC concentration,the order was Baohe district>Yaohai district>High-tech district>Luyang district. The correlation coefficients of OC and EC during the sampling period were respectively 0.6167 and 0.8763. High correlation of both OC and EC indicated that the main sources for OC and EC in Hefei city were the emission of automobile exhaust and the burning of coals.(3) During the sampling period in spring and summer, the concentration ratios of NH4+/SO42-and NH4+/NO3- were respectively 0.43 and 0.41, manifesting that ammonium salt was the main component of soluble ions in the atmosphere in the main urban area of Hefei city and the ammonium salt existed in the form of ammonium sulfate salt as well as ammonium nitrate salt. The correlation coefficient of NH4+and SO42- was 0.94 and the the ammonium salt existed mainly in the form of sulfate radical. The correlation coefficient of Mg2+ and Ca2+ was 0.76, manifesting that construction fugitive dust was the main contributor to soil fugitive dust.(4) The average concentrations of PAHs during the two seasons for sampling were respectively 37.104 ng/m3 and 4.403 ng/m3, the average concentration in spring surpassing that in summer. Benzo (b) fluoranthrene (BbF) and phenanthrene (PHE) were respectively monomers of the highest concentration during spring and summer. In spring, the value of BaPE was 3.792 ng/m3 and PAHs in the PM10 was of relatively serious harm to human. The concentration ratio of four ring aromatic hydrocarbon and five-six ring aromatic hydrocarbon was 0.529, indicating that PAHs pollution in Hefei was mainly influenced by local sources of pollution. The concentration ratio of benzo (a) pyrene (BaP) and benzo (g, h, i) perylene (BPe) was 0.63, manifesting that PAHs in Hefei mainly came from the composite pollution of coal burning and transportation.