EGU21-576
https://doi.org/10.5194/egusphere-egu21-576
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

On mineral dust hygroscopicity

Mingjin Tang, Lanxiadi Chen, Chao Peng, and Wenjun Gu
Mingjin Tang et al.
  • Chinese Academy of Science, Guangzhou Institute of Geochemistry, Guangzhou, China (mingjintang@gig.ac.cn)

Despite its importance, hygroscopicity of mineral dust aerosol remains highly uncertain. In this work, we investigated water adsorption and hygroscopicity of different mineral dust samples at 25 ∘C, via measurement of sample mass at different relative humidity (RH, up to 90 %) using a vapor sorption analyzer. Mineral dust samples examined (21 in total) included seven authentic mineral dust samples from different regions in the world and 14 major minerals contained in mineral dust aerosol. At 90 % RH, the mass ratios of adsorbed water to the dry mineral ranged from 0.0011 to 0.3080, largely depending on the BET surface areas of mineral dust samples. The fractional surface coverages of adsorbed water were determined to vary between 1.26 and 8.63 at 90 % RH, and it was found that the Frenkel–Halsey–Hill (FHH) adsorption isotherm could describe surface coverages of adsorbed water as a function of RH well, with AFHH and BFHH parameters in the range of 0.15–4.39 and 1.10–1.91, respectively. The comprehensive and robust data obtained would largely improve our knowledge of hygroscopicity of mineral dust aerosol.

How to cite: Tang, M., Chen, L., Peng, C., and Gu, W.: On mineral dust hygroscopicity, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-576, https://doi.org/10.5194/egusphere-egu21-576, 2021.