Details

Autor(en) / Beteiligte

• Jang, Eui-Soung
• Mickols, William
• Sujanani, Rahul
• Helenic, Alysha
• Dilenschneider, Theodore J.
• Kamcev, Jovan
• Paul, Donald R.
• Freeman, Benny D.

Titel

Influence of concentration polarization and thermodynamic non-ideality on salt transport in reverse osmosis membranes

Ist Teil von

• Journal of membrane science, 2019-02, Vol.572 (C), p.668-675

Ort / Verlag

United States: Elsevier B.V

Erscheinungsjahr

2019

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The classic Merten and Lonsdale transport model for reverse osmosis membranes was reformulated to explicitly demonstrate the effects of concentration polarization and solution phase thermodynamic non-idealities on salt transport. A framework presented here accounts for the concentration dependence of ion activity coefficients in salt solutions, which was not explicitly included in the classic model. This approach was applied to four salt solutions, NaCl, MgCl2, CaCl2, and Na2SO4, tested in cross-flow conditions for a commercial RO membrane, Dow Filmtec™ BW30XFR. Salt transport coefficients corrected for concentration polarization and non-ideal thermodynamic effects, Ba, were calculated as a function of permeate flux and compared with apparent salt transport coefficients, B. These corrections were significant, resulting in Ba values greater than B values by a factor of 1.3–2.1 for 2:1 and 1:2 salts (i.e., MgCl2, CaCl2, and Na2SO4). Ba values for NaCl (a 1:1 salt), however, were similar to or somewhat smaller than B values. •A theoretical framework accounting for concentration polarization and non-ideal thermodynamic effects on salt transport in RO membranes is proposed.•The influence of concentration polarization and thermodynamic non-idealities on salt transport coefficients (i.e., B values) in RO membranes was quantified.•Corrections for concentration polarization and non-ideal thermodynamic effects (i.e., Ba values) were significant, resulting in Ba values that were greater than B values by a factor of 1.3–2.1 for MgCl2, CaCl2, and Na2SO4 solutions.