Salt partitioning and transport in polyamide reverse osmosis membranes at ultrahigh pressures

Kevin Pataroque; Jishan Wu; Jinlong He; Hanqing Fan; Subhamoy Mahajan; Kevin Guo; Jason Le; Kay Au; Li Wang; Ying Li; Eric M.V. Hoek; Menachem Elimelech

Journal of Membrane Science Letters (Dec 2024)

Salt partitioning and transport in polyamide reverse osmosis membranes at ultrahigh pressures

Kevin Pataroque,
Jishan Wu,
Jinlong He,
Hanqing Fan,
Subhamoy Mahajan,
Kevin Guo,
Jason Le,
Kay Au,
Li Wang,
Ying Li,
Eric M.V. Hoek,
Menachem Elimelech

Affiliations

Kevin Pataroque: Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06520-8286, USA
Jishan Wu: Department of Civil & Environmental Engineering, University of California, Los Angeles, California, 90095, USA
Jinlong He: Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI 53706-1572, USA
Hanqing Fan: Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06520-8286, USA
Subhamoy Mahajan: Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI 53706-1572, USA
Kevin Guo: Department of Chemical Engineering, University of California, Los Angeles, California, USA
Jason Le: Department of Chemical Engineering, University of California, Los Angeles, California, USA
Kay Au: Department of Chemical Engineering, University of California, Los Angeles, California, USA
Li Wang: Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06520-8286, USA; State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
Ying Li: Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI 53706-1572, USA
Eric M.V. Hoek: Department of Civil & Environmental Engineering, University of California, Los Angeles, California, 90095, USA; Energy Storage and Distributed Resources Division, Lawrence Berkeley National Lab, Berkeley, CA, 94720, USA; Corresponding author at: Department of Civil & Environmental Engineering, University of California, Los Angeles, California, 90095, USA. Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06520-8286, USA.
Menachem Elimelech: Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06520-8286, USA; Corresponding author at: Department of Civil & Environmental Engineering, University of California, Los Angeles, California, 90095, USA. Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06520-8286, USA.

Journal volume & issue: Vol. 4, no. 2
p. 100079

Abstract

Read online

Understanding salt and water transport mechanisms in reverse osmosis (RO) under high pressures and salinities is critical to advancing RO-based brine management technologies. In this study, we investigate the dependence of salt permeance and partitioning on feed salinity and applied pressure. Salt partitioning coefficients were determined using a novel high-pressure quartz crystal microbalance (QCM), and salt permeances were collected using a lab-scale high-pressure dead-end cell. Our results show that salt permeance decreases with respect to feed concentration, in contrast to conventional theories for charged RO membranes. We further show salt partitioning coefficients do not change with applied hydrostatic pressure but are dependent on feed salt concentration. We use non-equilibrium molecular dynamics simulations to show that these trends are explained by salinity and pressure-induced changes to the structure of the polyamide layer, namely osmotic deswelling and compaction. Changes in the polyamide layer thickness and pore size alter the frictional interactions of ions, affecting membrane performance at larger salinities and pressures. These results provide new insights on how structure-performance relationships affect salt transport at higher pressures.

Published in Journal of Membrane Science Letters

ISSN: 2772-4212 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Science: Chemistry
Website: https://www.journals.elsevier.com/journal-of-membrane-science-letters

About the journal

Abstract

Keywords