Along with windblown dust, large quantities of pollutants are annually brought out of the continental by the westerlies in winter and spring; thereafter they are partly subjected to transport by northeastern monsoon w...Along with windblown dust, large quantities of pollutants are annually brought out of the continental by the westerlies in winter and spring; thereafter they are partly subjected to transport by northeastern monsoon winds to Taiwan. Both PM10 and PM2.5 aerosols collected from northern Taiwan from February 2002 to March 2003 were determined for three heavy metals, namely Pb, Cd and Zn, to characterize the heavy metal compositions between long-range transported and local aerosols and to evaluate their contributions of long-range transport during the northeastern monsoon season. Low Cd/Pb (0.017) and Zn/Pb (1.82) ratios were measured in aerosols during the Asian dust period, in which the sources of ambient aerosols are dominated by long-range transport. By contrast, high Cd/Pb(0.030) and Zn/Pb (3.44) ratios were measured during the summer monsoon season, in which local pollutant emissions dominate the sources of heavy metals. Such characteristic Cd/Pb and Zn/Pb ratios appear to be successfully applied to identify the pollutants originated from the long-range transport or local emissions.展开更多
The speciation of the elements on the surface of the particles collected during dust storm and non-dust storm in Beijing and Inner Mongolia was studied by XPS. The ma- jor species of iron on the surface were oxides, s...The speciation of the elements on the surface of the particles collected during dust storm and non-dust storm in Beijing and Inner Mongolia was studied by XPS. The ma- jor species of iron on the surface were oxides, sulfate, silicate, FeOOH and minor part sorbed on SiO2/Al2O3. Sulfate is the dominant species of sulfur on the surface. SiO2 and Al2O3 are the main components of Si and Al on the surface respectively. One of the most important findings was that the Fe(II) (FeS and FeSO4) produced could account for up to 44.3% and 45.6% of the total Fe on the surface in the aerosol sample collected at that night and next day of the “peak” time of the dust storm occurring on March 20, 2002, while Fe2(SO4)3, one of the Fe(III) species on the surface decreased from 67.1% to 49.5% and 48.0% respectively. Both S and Fe en- riched on the surface of aerosol particles. Fe(II) accounted for 1.3%?5.3% of total Fe in bulk aerosol samples during dust storm. These results provided strong evidence to sup- port the hypothesis of the coupling between iron and sulfur in aerosols during the long-range transport, which would have important impact on the global biogeochemical cycle.展开更多
文摘Along with windblown dust, large quantities of pollutants are annually brought out of the continental by the westerlies in winter and spring; thereafter they are partly subjected to transport by northeastern monsoon winds to Taiwan. Both PM10 and PM2.5 aerosols collected from northern Taiwan from February 2002 to March 2003 were determined for three heavy metals, namely Pb, Cd and Zn, to characterize the heavy metal compositions between long-range transported and local aerosols and to evaluate their contributions of long-range transport during the northeastern monsoon season. Low Cd/Pb (0.017) and Zn/Pb (1.82) ratios were measured in aerosols during the Asian dust period, in which the sources of ambient aerosols are dominated by long-range transport. By contrast, high Cd/Pb(0.030) and Zn/Pb (3.44) ratios were measured during the summer monsoon season, in which local pollutant emissions dominate the sources of heavy metals. Such characteristic Cd/Pb and Zn/Pb ratios appear to be successfully applied to identify the pollutants originated from the long-range transport or local emissions.
基金supported by the National Natural Science Foundation of China(Grant Nos.29837190,20077004,and 30230310)Bejjing Natural Science Fund(Grant Nos.8991002 and 8041003)+2 种基金supported by the special fund for doctoral study from the Ministry of EducationLAPC,Institute of Atmospheric Physica,CASthe Swedish Intermational Development Cooperation Agency(SIDA)through the Asian Regional Research Program on Environmental Technology(ARRPET)at the Asian Institute of Technology.
文摘The speciation of the elements on the surface of the particles collected during dust storm and non-dust storm in Beijing and Inner Mongolia was studied by XPS. The ma- jor species of iron on the surface were oxides, sulfate, silicate, FeOOH and minor part sorbed on SiO2/Al2O3. Sulfate is the dominant species of sulfur on the surface. SiO2 and Al2O3 are the main components of Si and Al on the surface respectively. One of the most important findings was that the Fe(II) (FeS and FeSO4) produced could account for up to 44.3% and 45.6% of the total Fe on the surface in the aerosol sample collected at that night and next day of the “peak” time of the dust storm occurring on March 20, 2002, while Fe2(SO4)3, one of the Fe(III) species on the surface decreased from 67.1% to 49.5% and 48.0% respectively. Both S and Fe en- riched on the surface of aerosol particles. Fe(II) accounted for 1.3%?5.3% of total Fe in bulk aerosol samples during dust storm. These results provided strong evidence to sup- port the hypothesis of the coupling between iron and sulfur in aerosols during the long-range transport, which would have important impact on the global biogeochemical cycle.
