本研究旨在探討掃街作用對周界懸浮微粒之逐時變化及削減效率對空氣品質之改善成效,配合理論分析以及實場掃街作業對周界之懸浮微粒及路面街塵的削減率來進行評估。此外,為探討影響掃作業成效之因子為何,亦針對掃街作業其他相關影響因子來進行研究。 本研究所選取之街道為某市主要的10條重點道路,其平均車流量約為43.6 pcu/min,塵土、坋土含量分別在1.9 ~ 9.0 g/m2及0.5 ~ 1.6 g/m2;掃街車之操作條件:掃帚轉速為50 rpm/min、掃帚角度為45°;掃街車以時速5 ~ 8 km/hr進行洗掃,掃街範圍為道路之慢車道。PM10監測時間為掃街作業前20分鐘開始監測,待掃街過後持續監測至1小時,路面塵土及坋土採樣則為掃街作業前後進行之。 研究結果發現,在進行掃街作業時PM10之動態變化的部分,因機具施作特性造成街塵之再揚起,街塵與道路表面間附著力降低,使PM10濃度瞬間暫時性增高,而在經過4~6分鐘之回復時間(Time of Response,tr)後可以逐漸回復至掃街前之水準,且風速與回復時間有密切的關係(R2=0.8131)。且良好的掃街作業對街道周界之PM10及路面塵/坋土皆具有正面的削減效率(ηp、ηd及ηs)其中ηs與ηp具有一定之相關性(其R2值為0.2988)。
The objective of this study was to evaluate dynamic PM10 variability and an effective(ηp、ηd、ηs) method for controlling air quality in Taiwan. It applied a modified regenerative vacuum sweeper and efficient washer to evaluate the effectiveness of sweeping. Effects of traffic volume and wind velocity on the sweeping efficiencies are also discussed in the paper. Dynamic PM10 variability was measured to evaluate of the sweeping effectiveness. It was found that the direct impact of sweeping on ambient PM10 concentration was shortly lived, lasting no more about 4-6 minutes. Effectiveness of sweeping for controlling ambient PM10 was evaluated by PM10 measurements and determining silt load from activities traffic streets. It did good job collecting the visible fine particles on roads, the method of sweeping tested was effective at removing the sources of the road dust particles. The sweeping efficiencies were obtained based on the experimental data of silt loading, PM10, and the relationship of the two efficiencies also can be expressed.