| 被动采集大气颗粒物样品的粒径分布特征 |
| 摘要点击 1626 全文点击 2199 投稿时间：2009-05-21 修订日期：2009-07-29 |
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| 中文关键词 被动采样装置 颗粒物 粒径分布 风速 滤网 |
| 英文关键词 passive sampler particulate size distribution wind speed mesh |
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| 中文摘要 |
| 在可同时采集气态与颗粒态大气污染物的被动采样装置中放置涂有薄层凡士林的载玻片，用于采集大气悬浮颗粒物，利用粒度粒形仪分析样品粒径分布特征，并深入探讨风速以及采样罐外壁添加300目滤网(孔径50 μm)对样品粒径分布的影响.结果表明，在室内静风与室外相对封闭的条件下，添加滤网可有效阻止>50 μm的粗颗粒组分进入采样罐；而在室外有风的条件下，添加滤网后仍有粗颗粒进入采样罐中，但进入概率与风速大小之间无关.观察粒径10 μm以下颗粒的分布曲线，室内静风条件下得到的分布曲线与主动采样得到的结果极为类似.而在有风条件下，3～5 μm的颗粒组分比重有所减少，6～9 μm颗粒组分比重明显增加.上述问题在被动采样器的使用中需予以考虑，结合样点具体情况判断是否添加滤网. |
| 英文摘要 |
| Airborn particulate matters were sampled by two duplicate glass slides coated with thin layer of vaseline laid at the bottom of sampling cylinder of passive sampler for collecting both gaseous and particulate phase semi-volatile organic pollutant. Their size distribution was analyzed and found to be influenced by wind speed and coverage of the fine-screen-mesh (300 mesh) wrapping around the outside of sampling cylinder. In a windless (indoor) and semi-static windy conditions (sealed courtyard), diffusion of coarse particles (>50 μm) was reduced effectively by covering sampling cylinder with the fine-screen-mesh, and accumulated size distribution curve of PMx was similar with those collected by an active size-fractionated sampler (cascade impactor). In windy conditions (outdoor), coarse particles entered the sampling cylinder randomly, which is independent with wind speed, while the percentage of fine particulate with size of 3-5 μm decreased and those with size of 6-9 μm increased significantly. |
