大气POPs被动采样中雾霾效应研究

Polyurethane foam-based passive air samplers (PUF-PAS) are one of the most widely used PAS for monitoring persistent organic pollutants (POPs), and they can be used to measure seasonally resolved concentrations of atmospheric POPs. A great deal of researches have been carried out focusing on the monitoring of POPs by PUF-PAS in China. The PAS techniques for monitoring POPs are influenced by environmental factors such as temperature, wind speed and atmospheric particles. During last decade, haze-fog weather occurs frequently in China, and ambient air contains millions of particles. The influence of atmospheric particles is documented in estimating air concentration of POPs by PUF-PAS, yet few studies have looked into the feasibility of PUF-PAS in monitoring during haze-fog weather. The study intends to explore the potential influence of environmental factor on the PUF-PAS in monitoring POPs during haze-fog weather. Xi’an city is selected as study area, and some experimental field studies and indoor simulation test will be performed, such as the comparative study of PUF-PAS and high-volume active air samplers, the relationship of size distribution of the particles and POPs, the variation of POP concentration with altitude. Improved PUF-PAS suitable for particle-associated chemicals as well as volatile chemicals will be developed. These research results could provide theory gist to effectively apply the PUF-PAS in monitoring POPs during haze-fog weather.

聚氨酯泡沫碟片被动采样器（PUF-PAS）是目前全球使用最为广泛的大气被动采样器，可用于季节分辨率的大气持久性有机污染物（POPs）监测。我国已开展了大量使用PUF-PAS监测大气POPs的研究项目。大气中POPs的被动采样技术受温度、风速和大气颗粒物等环境因素影响。近十几年来，我国雾霾天气频发，空气中高含量的颗粒物会影响PAS的采样效果，然而尚未见到针对雾霾天气下大气被动采样技术可行性的研究报道。本研究以西安为研究区，拟开展雾霾天气条件下，主动采样技术和PUF-PAS采样对比、大气颗粒物中POPs的粒径分布和不同高程POPs的梯度变化等研究，探究环境因素对大气POPs的被动采样技术的影响机理；并对PUF-PAS进行改进，开展室内模拟和野外校正实验，探究其能否满足雾霾天气下大气POPs的监测要求。研究成果将为大气POPs的被动采样技术在全天候（尤其是雾霾天气）的使用提供理论依据和技术支撑。

持久性有机污染物（POPs）是一类易于随大气远距离迁移的高毒性难降解污染物，能够对人类健康和生态环境造成严重危害。大气可以快速响应POPs的区域使用的排放变化，但是大气POPs样品的获取一直是研究的难点之一。被动采样技术是近年来颇受欢迎的热点技术，实现了对大气POPs的大尺度污染状况的同步观测和小尺度的环境空气质量监测。作为使用最为广泛的大气被动采样器，聚氨酯泡沫碟片被动采样器（PUF-PAS）已经在全球范围内用于提供大气POPs的浓度时间和空间变化趋势。但是，PUF-PAS的采样效率受温度、风速和颗粒物等环境因素影响，采样点的环境状况可能造成估算大气中POPs浓度的不确定性，产生误差。因此，探究雾霾污染对大气POPs被动采样的影响是大气POPs监测的迫切需求。本项目在武汉设置监测点位，利用大气主动采样器和PUF-PAS收集冬季雾霾期间大气POPs样品，分析测试了样品中多环芳烃（PAHs）及其衍生物和大气颗粒物化学组成。结果表明在研究期间共发生五次雾霾的生消过程，大气中PAHs主要来源于燃煤及化石燃料的燃烧，PUF-PAS对大气中不同PAHs组分的捕集随高程变化存在不同程度差异，但受温度和风速的影响相对较小。相关研究成果可为大气POPs的被动采样技术的研发提供理论依据和技术支撑。