TY - JOUR
T1 - Experimental investigation of the effect of ion concentration and its valence on reflection coefficient and solute permeability of nf membranes
AU - Al-Saadi, Amal
AU - Mousa, Hasan
AU - Reza Vakili-Nezhaad, G.
AU - Gujarathi, Ashish M.
N1 - Funding Information:
The authors appreciate the financial support of Sultan Qaboos University and University of South Africa through the joint research funding (CL/SQU-SA/18/04).
Publisher Copyright:
© 2021 Desalination Publications. All rights reserved.
PY - 2021/2
Y1 - 2021/2
N2 - The objective of this manuscript is to investigate experimentally and theoretically the effect of ion (cation and anion) valence and concentration on the rejection coefficient and solute permeability of NF270 membrane. The experimental data of solute rejection vs. permeate flux is usually fitted to Spiegler-Kedem equation to determine the reflection coefficient and the solute permeability. In doing so, many problems may arise such as inaccurate numerical fitting, the discrepancy in the results when the different initial guess is made and sometimes no result is obtained. The current research work overcomes these problems by transferring the Spiegler-Kedem equation to a one-parameter equation. This is done by first using the flux equation to determine the rejection coefficient and use this data in the Spiegler-Kedem equation to determine the solute permeability. The success of this procedure was confirmed by comparing its results with those available in open literature where an excellent agreement was found. Moreover, the values of the reflection coefficient and the solute permeability that some researchers could not determine were found. The interaction between the solutes especially at high concentrations was taken into account when the osmotic pressure was calculated. The experimental results showed that σ is inversely proportional to the concentration. Ps, however, are proportional to the concentration until a certain concentration is reached after which the effect diminishes. The results also show that as the valence of the cation increases both σ and Ps increase. The results showed that AlCl3 has the highest value of s and NaCl has the lowest value. The values of s follow the following order: σ AlCl3 σ > MgCl2 σ > Na2SO4 σ > NaCl. The dependence of Ps on the solute type follows the following order Ps,NaCl > Ps,Na2SO4 > Ps,MgCl2 > Ps,AlCl3.
AB - The objective of this manuscript is to investigate experimentally and theoretically the effect of ion (cation and anion) valence and concentration on the rejection coefficient and solute permeability of NF270 membrane. The experimental data of solute rejection vs. permeate flux is usually fitted to Spiegler-Kedem equation to determine the reflection coefficient and the solute permeability. In doing so, many problems may arise such as inaccurate numerical fitting, the discrepancy in the results when the different initial guess is made and sometimes no result is obtained. The current research work overcomes these problems by transferring the Spiegler-Kedem equation to a one-parameter equation. This is done by first using the flux equation to determine the rejection coefficient and use this data in the Spiegler-Kedem equation to determine the solute permeability. The success of this procedure was confirmed by comparing its results with those available in open literature where an excellent agreement was found. Moreover, the values of the reflection coefficient and the solute permeability that some researchers could not determine were found. The interaction between the solutes especially at high concentrations was taken into account when the osmotic pressure was calculated. The experimental results showed that σ is inversely proportional to the concentration. Ps, however, are proportional to the concentration until a certain concentration is reached after which the effect diminishes. The results also show that as the valence of the cation increases both σ and Ps increase. The results showed that AlCl3 has the highest value of s and NaCl has the lowest value. The values of s follow the following order: σ AlCl3 σ > MgCl2 σ > Na2SO4 σ > NaCl. The dependence of Ps on the solute type follows the following order Ps,NaCl > Ps,Na2SO4 > Ps,MgCl2 > Ps,AlCl3.
KW - Membrane
KW - Nanofiltration
KW - Permeability
KW - Reflection coefficient
KW - Rejection
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U2 - 10.5004/dwt.2021.26642
DO - 10.5004/dwt.2021.26642
M3 - Article
AN - SCOPUS:85102152409
SN - 1944-3994
VL - 212
SP - 276
EP - 285
JO - Desalination and Water Treatment
JF - Desalination and Water Treatment
ER -