| Abstract: | 為了要了解台中地區大氣中懸浮微粒的特性,本研究在台中地區交通污染源設置了乾沉降板,PS-1,MOUDI及NRI採樣器;在台中地區之膠區設置了乾沉降板,PS-1,MOUDI及Universal採樣器.用來量測大氣中的乾沉降通量及大氣中懸浮微粒之濃度.通常來說,白天大氣中之乾沉降通量及懸浮微粒濃度不管是在交通區或郊區都會比夜晚來得大.對於交通區懸浮微粒之粒徑分布來說,在風速較高的情況下其粒徑分布會往較大粒徑方向移動.在乾沉降通量及懸浮微粒濃度對風速的回歸(R2)方面,結果顯示白天受到較多其它因素的干擾(如交通流量及人們的活動)因而降低了風速對乾沉降通量及懸浮微粒濃度的影響. 本研究在預測乾沉降方面使用了NRI,MOUDI及Universal採樣器.利用Noll&Fang模式模擬的結果顯示,構成乾沉降的主要部份為粒徑大於10 um的懸浮微粒.至於各種採樣器的比較方面,利用Universal採樣器代替準備工作較麻煩的MOUDI再加上NRI也是能夠有效的預測乾沉降值.
Dry deposition plates, PS-1, MOUDI (micro orifice uniform deposit impacotr)and NRI (Noll rotary impactor) sampler were used to measure dry deposition fluxes, ambient particle concentrations during day and night periods at a traffic sampling site in Taichung. Dry deposition plates, PS-1, MOUDI and Universal sampler were used to collect dry deposition fluxes and ambientparticle concentrations during day and night periods at a rural samplingsite in Taichung. Generally, dry deposition flux and particle concentrationare larger during the day period at both the traffic and the rural samplingsite. Furthermore, the particle size distribution shifts to large particle mode at higher wind speed for the traffic sampling site. The correlationcoefficient (R2) among dry deposition flux, particle concentration and windspeed in the night period are better than the day period. The reasons arethat there are more influence factors in the day period, thus, reducing theinfluence caused by wind speed. NRI, MOUDI and Universal sampler were used in predicting dry depositionin this study. The results of models show that the majority of the flux isdue to particles greater than 10 um in size. The results obtained by comparison of simultaneous measurements of PM2.5, PM2.5-10, coarse particles (> 10 um) and dry deposition fluxes suggest that the combination of NRI withUniversal sampler can be applied to predict dry deposition more accurately |
