School of Environment, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Normal University, Xinxiang 453007, PR China.
International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (HIT), Harbin 150090, PR China; Hangzhou PuYu Technology Development Co., Ltd., Hangzhou 311300, PR China.
J Hazard Mater. 2023 Aug 5;455:131639. doi: 10.1016/j.jhazmat.2023.131639. Epub 2023 May 13.
The floating catkins generated by willow and poplar trees have been criticized for spreading germ and causing fire for decades. It has been found that catkins are with a hollow tubular structure, which made us wonder if the floating catkins can adsorb atmospheric pollutions. Thus, we conducted a project in Harbin, China to investigate whether and how willow catkins could adsorb atmospheric polycyclic aromatic hydrocarbons (PAHs). The results suggest that both the catkins floating in the air and on the ground preferred to adsorb gaseous PAHs rather than particulate PAHs. Moreover, 3- and 4-ring PAHs were the dominating compositions adsorbed by catkins, which significantly increased with exposure time. The gas/catkins partition (K) was defined, which explained why 3-ring PAHs are more easily adsorbed by catkins than by airborne particles when their subcooled liquid vapor pressure is high (log P > -1.73). The removal loading of atmospheric PAHs by catkins were estimated as 1.03 kg/year in the center city of Harbin, which may well explain the phenomenon that levels of gaseous and total (particle + gas) PAHs are relatively low in the months with catkins floating reported in peer-reviewed papers.
杨柳飞絮数十年来一直饱受诟病，既传播病菌又易引发火灾。人们发现，柳絮呈中空管状结构，这不禁让人好奇柳絮是否可以吸附大气中的污染物。因此，我们在中国哈尔滨开展了一个项目，以研究柳树的柳絮是否以及如何吸附大气中的多环芳烃 (PAHs)。结果表明，无论是漂浮在空气中还是地面上的柳絮，都更倾向于吸附气态 PAHs，而不是颗粒态 PAHs。此外，3 环和 4 环 PAHs 是被柳絮吸附的主要成分，其含量随着暴露时间的增加而显著增加。我们定义了气/絮分配系数 (K)，这解释了当 3 环 PAHs 的亚临界液体蒸气压较高（log P > -1.73）时，为什么其比空气颗粒物更容易被柳絮吸附。在哈尔滨市中心，我们估计每 1 年柳树可去除大气 PAHs 的量为 1.03 千克，这很好地解释了在柳絮飞扬的月份，大气中气态和总（颗粒态+气态）PAHs 浓度相对较低的现象。
