TY - JOUR
T1 - Influence of the external conditions on salt retention and pressure-induced electrical potential measured across a composite membrane
AU - Benavente, Juana
AU - Jonsson, Gunnar Eigil
PY - 1999
Y1 - 1999
N2 - Transport on single electrolyte solutions (NaCl and MgCl2) due to pressure gradients across a commercial reverse osmosis membrane was studied by measuring volume flux (J(v)), salt rejection (S) and pressure induced electrical potential (Delta E) in a crossflow cell. The influence on these parameters of different external conditions due to hydrodynamic or chemical changes in the feed solutions was also studied. Changes were carried out by variation of the feed solution velocity (Reynolds numbers between 1500 and 3300) or the concentration ratio of mixed electrolytes (r = HCl/NaCl and HCl/MgCl2, r = 1, 0.5 and 0.1), respectively. Results show that J(v), S and Delta E values slightly increase when the velocity of the feed solution increases, but the mixed electrolytes strongly affect both salt rejection and pressure-induced electrical potential. A change in the sign of both parameters with respect to the value determined with single electrolytes at the same concentration was obtained, which is attributed to a strong coupling among the fluxes of individual ions and their distribution in the membrane when transport of mixed salt is studied. (C) 1999 Elsevier Science B.V. All rights reserved.
AB - Transport on single electrolyte solutions (NaCl and MgCl2) due to pressure gradients across a commercial reverse osmosis membrane was studied by measuring volume flux (J(v)), salt rejection (S) and pressure induced electrical potential (Delta E) in a crossflow cell. The influence on these parameters of different external conditions due to hydrodynamic or chemical changes in the feed solutions was also studied. Changes were carried out by variation of the feed solution velocity (Reynolds numbers between 1500 and 3300) or the concentration ratio of mixed electrolytes (r = HCl/NaCl and HCl/MgCl2, r = 1, 0.5 and 0.1), respectively. Results show that J(v), S and Delta E values slightly increase when the velocity of the feed solution increases, but the mixed electrolytes strongly affect both salt rejection and pressure-induced electrical potential. A change in the sign of both parameters with respect to the value determined with single electrolytes at the same concentration was obtained, which is attributed to a strong coupling among the fluxes of individual ions and their distribution in the membrane when transport of mixed salt is studied. (C) 1999 Elsevier Science B.V. All rights reserved.
U2 - 10.1016/S0927-7757(99)00267-8
DO - 10.1016/S0927-7757(99)00267-8
M3 - Journal article
SN - 0927-7757
VL - 159
SP - 431
EP - 437
JO - Colloids and Surfaces A: Physicochemical and Engineering Aspects
JF - Colloids and Surfaces A: Physicochemical and Engineering Aspects
IS - 2-3
ER -