粉尘与环境研究室知识库

PM(10) and size-segregated samples were simultaneously collected at Mt. Hua (2060 ma.s.l.) and Mt. Tai (1545 ma.s.l.) in central and east coastal China during spring, 2009 including an intensive dust storm event occurring on 24 April, and determined for EC, OC and inorganic ions. During the non-dust storm period particles, EC, OC and ions except for SO(4)(2-) were 2-10 times more abundant at Mt. Tai than at Mt. Hua. SO(4)(2-) (13 +/- 7.1 mu g m(-3)) at Mt. Hua was the dominant ion, followed by NO(3)(-) (5.0 +/- 3.9 mu g m(-3)), NH(4)(+) (2.5 +/- 1.3 mu g m(-3)) and Ca(2+) (1.6 +/- 0.8 mu g m(-3)). In contrast, at Mt. Tai NO(3)(-) was most abundant (20 +/- 14 mu g m(-3)), followed by SO(4)(2-) (16 +/- 13 mu g m(-3)), NH(4)(+) (12 +/- 8.9 mu g m(-3)) and Ca(2+) (3.9 +/- 2.1 mu g m(-3)). The fact of NO(3)(-) exceeding over SO(4)(2-) at Mt. Tai may suggest the changes in chemical composition of the atmosphere over east China due to sharply increasing vehicle emission. pH values of the water-extracts of PM(10) samples indicate that at the two mountain sites aerosols transported from the south regions are more acidic than those from the north and more acidic at Mt. Tai than at Mt. Hua during the non-dust storm period. During the dust storm event particle mass, OC, Na(+), K(+), Mg(2+) and Ca(2+) at both sites increased by a factor of 1-9, while EC, NO(3)(-) and NH(4)(+) decreased by 20-80 %. However, SO(4)(2-) concentrations (13 +/- 7.7 mu g m(-3) at Mt. Hua and 15 +/- 5.6 mu g m(-3) at Mt. Tai, respectively) at the two sites during the episode were comparable and did not change significantly compared to those in the non-dust storm period, probably due to a similar level of free tropospheric SO(2) in central and east China.