包覆有二次有机气溶胶的硫酸铵颗粒的风化转变

Efflorescence transitions of ammonium sulfate particles coated with secondary organic aerosol.

作者信息

Takahama Satoshi, Pathak Ravi K, Pandis Spyros N

机构信息

Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.

出版信息

Environ Sci Technol. 2007 Apr 1;41(7):2289-95. doi: 10.1021/es0619915.

DOI:10.1021/es0619915

PMID:17438777

Abstract

Ammonium sulfate particles were generated by atomization and introduced into a smog chamber where they were coated with secondary organic aerosol from ozonolysis of limonene or alpha-pinene. These mixed particles were then sampled with a humidified Tandem-DMA system where a monodisperse aerosol population was selected, humidified, and dried to observe the relative humidity (RH) at which the particles returned to the original dry diameter. The volume fraction of secondary organic aerosol (SOA) in the mixed particles ranged from 0.59 to 0.94 for limonene SOA and 0.54 to 0.72 for alpha-pinene SOA. Efflorescence RHs for our mixed aerosols were in the range of 28-34%, similar to our observation of 32% ERH for pure ammonium sulfate nanoparticles. These findings indicate that the effect of SOA on the ERH of inorganic salts in the atmosphere may be negligible.

摘要

通过雾化产生硫酸铵颗粒，并将其引入烟雾室，在那里它们被来自柠檬烯或α-蒎烯臭氧分解产生的二次有机气溶胶包覆。然后用加湿串联差分电迁移分析仪系统对这些混合颗粒进行采样，在该系统中选择单分散气溶胶群体，进行加湿和干燥，以观察颗粒恢复到原始干燥直径时的相对湿度（RH）。对于柠檬烯二次有机气溶胶（SOA），混合颗粒中SOA的体积分数范围为0.59至0.94，对于α-蒎烯SOA，该范围为0.54至0.72。我们混合气溶胶的风化相对湿度范围为28 - 34%，这与我们对纯硫酸铵纳米颗粒32%平衡相对湿度的观察结果相似。这些发现表明，SOA对大气中无机盐平衡相对湿度的影响可能可以忽略不计。