Dry deposition (downward, upward) concentration study of particulates and heavy metals during daytime, nighttime period at the traffic sampling site of Sha-Lu, Taiwan.
Downward, upward dry deposition fluxes and total suspended particulate of particulate heavy metals (Fe, Pb, Zn, Cu, Mg and Mn) were measured in daytime and nighttime period in Sha-Lu, a small city in the central Taiwan during summer period of 2003. The results showed that the total suspended particulate concentrations of particulate mass in the daytime period (averaged 996.2 g/m3) were higher than in nighttime period (averaged 560.7 g/m3). And the downward dry deposition fluxes (averaged 54.07 g/m2s) were about two times as that of upward dry deposition fluxes (averaged 26.48 g/m2s) in the daytime period. Furthermore, the average downward dry deposition fluxes (averaged 26.22 g/m2s) were also about two times as that of upward dry deposition fluxes (averaged 12.11 g/m2s) in the nighttime period. In addition, the average downward dry deposition fluxes are greater than the upward dry deposition fluxes for all the heavy metals in either daytime or nighttime period. The proposed reasons are that the wind speed and concentration difference for daytime and nighttime period lead to these results at the traffic sampling site of central Taiwan. In addition, the deposition velocity for mass, heavy metals (Fe, Pb, Zn, Cu, Mg and Mn) during daytime and nighttime period were also calculated. The average daytime dry deposition velocity for downward particulate mass, upward particulate mass, Fe, Pb, Zn, Cu, Mg and Mn were 5.56, 2.66, 1.71, 0.18, 1.06, 0.24, 0.47 and 0.11 (cm/s), respectively. And the average nighttime dry deposition velocity for downward particulate mass, upward particulate mass, Fe, Pb, Zn, Cu, Mg and Mn were 4.70, 2.11, 1.66, 0.18, 0.86, 0.23, 0.32 and 0.07 (cm/s), respectively at traffic sampling site of central Taiwan.
Fang
Guor-Cheng
GC
Air Toxic and Environmental Analysis Laboratory, Department of Environmental Engineering, Hungkuang Institute of Technology, Hungkuang University, Sha-Lu, Taichung 433, Taiwan. gcfang@sunrise.hk.edu.tw
Wu
Yuh-Shen
YS
Huang
Shih-Han
SH
Rau
Jui-Yeh
JY
D000393:Air Pollutants / Q000032:analysis*; D004784:Environmental Monitoring / Q000706:statistics & numerical data*; D019216:Metals, Heavy / Q000032:analysis*; D010316:Particle Size; D015203:Reproducibility of Results; D013624:Taiwan; D001335:Vehicle Emissions / Q000032:analysis*; D014919:Wind
D000393:Air Pollutants; D019216:Metals, Heavy; D001335:Vehicle Emissions