Impact of adsorption kinetics on pollutant dispersion in water flowing in nanopores: A Lattice Boltzmann approach to stationary and transient conditions. (April 2022)

• Record Type: Journal Article
• Authors: Zaafouri, Zaineb; Batôt, Guillaume; Nieto-Draghi, Carlos; Coasne, Benoit; Bauer, Daniela
• Is Part Of: Advances in water resources. Volume 162(2022)
• Publication Date: 2022-04
• Subjects: Dispersion -- Adsorption -- Kinetics -- Transient regime -- Cooperative adsorption -- Lattice Boltzmann -- TRT; Hydrology -- Periodicals; Hydrodynamics -- Periodicals; Hydraulic engineering -- Periodicals; 551.48
• DOI: 10.1016/j.advwatres.2022.104143
• Languages: English
• ISSNs: 0309-1708

Abstract

Abstract: We investigate the strong impact of adsorption thermodynamics and kinetics on particle dispersion using a robust numerical scheme: Lattice Boltzmann simulation within the Two Relaxation Time framework. By modeling the transport of both non-adsorbing and adsorbing molecules in simple pore structures, we highlight the key role played by the adsorption/desorption ratio k and the initial concentration c 0 (for different adsorption models Henry, Langmuir, etc.). Considering small k or c 0 leads to small or negligible adsorption impact on transport. However, for larger values, adsorption significantly alters transport as it drastically increases the dispersion of the adsorbing particles within the confining geometry. Our results highlight the need to include a robust thermodynamic modeling framework in transport equations when considering complex pollutants as they display a rich and complex physicochemical behavior. This includes surfactants, which are at the core of the present work, but also molecules of emerging concern such as heavy metals, microplastics, pharmaceuticals, etc. As illustrated here, with complex interfacial effects, large deviations can be observed in both the predicted adsorbed amounts and transport dispersion coefficients when compared to molecules with more conventional adsorption properties. Highlights: The Lattice Boltzmann scheme is extended to complex adsorption behavior. Micropollutants and surfactants follow complex aggregation effects on the surface. Adsorption thermodynamics and kinetics strongly influence pollutant dispersion. Different adsorption properties lead to specific transient régimes. Langmuir adsorption leads to Taylor dispersion in the long-time range.