Effect of microstructure in mesoporous adsorbents on the adsorption of low concentrations of VOCs: An experimental and simulation study

Yangyu Liu; Arman Peyravi; Xiongbo Dong; Zaher Hashisho; Shuilin Zheng; Xiao Chen; Du Gao; Yongxing Hao; Yuping Tong; Jiuyue Wang

doi:10.1016/j.jhazmat.2023.131934

Effect of microstructure in mesoporous adsorbents on the adsorption of low concentrations of VOCs: An experimental and simulation study

J Hazard Mater. 2023 Sep 15:458:131934. doi: 10.1016/j.jhazmat.2023.131934. Epub 2023 Jun 25.

Authors

Yangyu Liu¹, Arman Peyravi², Xiongbo Dong³, Zaher Hashisho⁴, Shuilin Zheng⁵, Xiao Chen⁶, Du Gao⁶, Yongxing Hao⁶, Yuping Tong⁷, Jiuyue Wang⁸

Affiliations

¹ School of Materials Science and Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450045, PR China; School of Chemical and Environment Engineering, China University of Mining and Technology (Beijing), Beijing 100083, PR China; Department of Civil and Environmental Engineering, University of Alberta, Edmonton AB T6G 2W2, Canada.
² Department of Civil and Environmental Engineering, University of Alberta, Edmonton AB T6G 2W2, Canada.
³ Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, PR China.
⁴ Department of Civil and Environmental Engineering, University of Alberta, Edmonton AB T6G 2W2, Canada. Electronic address: hashisho@ualberta.ca.
⁵ School of Chemical and Environment Engineering, China University of Mining and Technology (Beijing), Beijing 100083, PR China. Electronic address: zhengsl@cumtb.edu.cn.
⁶ School of Materials Science and Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450045, PR China.
⁷ School of Materials Science and Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450045, PR China. Electronic address: yptong_zz@163.com.
⁸ School of Art, North China University of Water Resources and Electric Power, Zhengzhou 450045, PR China.

PMID: 37390690
DOI: 10.1016/j.jhazmat.2023.131934

Abstract

This study evaluated the adsorption of five volatile organic compounds (VOCs) on Opoka, precipitated silica, and palygorskite, to elucidate the effect of their pore size on VOCs adsorption. The adsorption capacity of these adsorbents is not only highly correlated with their surface area and pore volume, but also notably improved by the presence of micropores. The variation in adsorption capacity for different VOCs was primarily influenced by their boiling point and polarity. Palygorskite, which had the smallest total pore volume (0.357 cm³/g) but the largest micropore volume (0.043 cm³/g) among the three adsorbents, exhibited the highest adsorption capacity for all tested VOCs. Additionally, the study constructed slit pore models of palygorskite with micropores (0.5 and 1.5 nm) and mesopores (3.0 and 6.0 nm), calculated and discussed the heat of adsorption, concentration distribution, and interaction energy of VOCs adsorbed on different pore models. The results revealed that the adsorption heat, concentration distribution, total interaction energy, and van der Waals energy decrease with increasing pore size. The concentration of VOCs in 0.5 nm pore was nearly three times that in 6.0 nm pore. This work can also provide guidance for further research on using adsorbents with mixed microporous and mesoporous structures to control VOCs.

Keywords: Adsorption; Desorption; Micropore; Molecular simulation; Volatile organic compounds.