Insights into adsorbent tortuosity across aqueous adsorption systems

Pore network, pore connectivity, and the resulting effective adsorbate pore diffusivity within an adsor-bent are critical physical considerations in mass transport modeling of aqueous adsorption. Tied to these three adsorbent features are the adsorbent tortuosity and tortuosity factor concepts. These concepts encompass the collective hindrance to intra-adsorbent adsorbate transport arising because of a disor-derly adsorbent porous topology. It is crucial for materials scientists, chemists, chemical engineers, and water treatment specialists to understand the complex and variable connections among adsorbate chemistry, adsorbent chemistry, adsorbent porosity, pore shape, size, and tortuosity, pore wall effect, adsorbate-adsorbent interactions, and adsorbate-adsorbate interactions in competitively contaminated aqueous environments. Adsorbent tortuosity has been sporadically studied in aqueous adsorption models. Despite the small population of these studies, insightful observations and inferences have been reported. However, as it appears, no review has been published to compile, compare, and contrast these aspects. Hence, this review concisely brings up those observations and interpretations around adsorbent tortuosity for aqueous adsorption systems. The notion of an adsorbent's tortuosity being single-valued is argued to be imprecise. Finally, perspectives are aired on possible research and development directions for elucidating the dynamic attributes of adsorbent tortuosity and applying them in real-scale adsorption-oriented water purification. The data acquired by filling in these research gaps can enable the design of adsorbents more adapted for real-scale water purification.(c) 2023 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Automated summary

Pore network, pore connectivity, and effective adsorbate pore diffusivity are crucial in mass transport modeling of aqueous adsorption. Adsorbent tortuosity and tortuosity factor concepts are related to these adsorbent features and hinder intra-adsorbent adsorbate transport. Understanding the complex connections among adsorbate chemistry, adsorbent chemistry, adsorbent porosity, pore shape, size, and tortuosity is important for water treatment specialists. This review provides insights into adsorbent tortuosity for aqueous adsorption systems and highlights the need for further research on dynamic attributes.