Non-steady diffusion and adsorption of organic micropollutants in ion-exchange membranes: effect of the membrane thickness

Malgorzata Roman; Pawel Roman; Rhea Verbeke; Leonardo Gutierrez; Marjolein Vanoppen; Marcel Dickmann; Werner Egger; Ivo Vankelecom; Jan Post; Emile Cornelissen; Karel Keesman; Arne Verliefde

doi:10.1016/j.isci.2021.102095

Non-steady diffusion and adsorption of organic micropollutants in ion-exchange membranes: effect of the membrane thickness

iScience. 2021 Jan 22;24(2):102095. doi: 10.1016/j.isci.2021.102095. eCollection 2021 Feb 19.

Authors

Malgorzata Roman^{1

2}, Pawel Roman¹, Rhea Verbeke³, Leonardo Gutierrez^{2

4}, Marjolein Vanoppen², Marcel Dickmann⁵, Werner Egger⁶, Ivo Vankelecom⁶, Jan Post¹, Emile Cornelissen^{2

7}, Karel Keesman^{1

8}, Arne Verliefde²

Affiliations

¹ Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, the Netherlands.
² Centre for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Particle and Interfacial Technology Group, Ghent University, Coupure Links 653, 9000 Ghent, Belgium.
³ Centre for Membrane Separations, Adsorption, Catalysis and Spectroscopy for Sustainable Solutions (cMACS), KU Leuven, Celestijnenlaan 200F p. o. box 2461, 3001 Leuven, Belgium.
⁴ Facultad del Mar y Medio Ambiente, Universidad Del Pacifico, Ecuador.
⁵ Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstr. 1, 85748 Garching, Germany and Physik-Department E21, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany.
⁶ Institut für Angewandte Physik und Messtechnik, Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85577 Neubiberg, Germany.
⁷ KWR Watercycle Research Institute, P.O. Box 1072, 3433 PE Nieuwegein, the Netherlands.
⁸ Mathematical and Statistical Methods - Biometris, Wageningen University and Research, P.O. Box 16, 6700 AA Wageningen, the Netherlands.

Abstract

There is no efficient wastewater treatment solution for removing organic micropollutants (OMPs), which, therefore, are continuously introduced to the Earth's surface waters. This creates a severe risk to aquatic ecosystems and human health. In emerging water treatment processes based on ion-exchange membranes (IEM), transport of OMPs through membranes remains unknown. We performed a comprehensive investigation of the OMP transport through a single IEM under non-steady-state conditions. For the first time, positron annihilation lifetime spectroscopy was used to study differences in the free volume element radius between anion- and cation-exchange membranes, and between their thicknesses. The dynamic diffusion-adsorption model was used to calculate the adsorption and diffusion coefficients of OMPs. Remarkably, diffusion coefficients increased with the membrane thickness, where its surface resistance was more evident in thinner membranes. Presented results will contribute to the improved design of next-generation IEMs with higher selectivity toward multiple types of organic compounds.

Keywords: chemical engineering; chemistry; environmental chemical engineering; environmental science.