Characterization and Prediction of Nanofiltration Membrane Performance—A General Assessment

Bowen, W. Richard; Mohammad, Abdul Wahab

doi:10.1205/026387698525685

Cited by 271 publications

(156 citation statements)

References 16 publications

Supporting

Mentioning

143

Contrasting

Order By: Relevance

“…Realizing the importance of the process as a prerequisite to running any model, Bowen and Mohammad later developed a simplified characterization method, and applied it to 29 NF membranes from 10 manufacturers [52]. The membrane pore dielectric constant was eventually added to the list of membrane parameters to account for dielectric exclusion [29].…”

Section: Membrane Characterizationmentioning

confidence: 99%

See 1 more Smart Citation

Fundamentals of low-pressure nanofiltration: Membrane characterization, modeling, and understanding the multi-ionic interactions in water softening

Labban

Liu

Chong

et al. 2017

Journal of Membrane Science

148

View full text Add to dashboard Cite

Recently, a novel class of low-pressure nanofiltration (NF) hollow fiber membranes, particularly suited for water softening and desalination pretreatment have been fabricated in-house using layer-by-layer (LbL) deposition with chemical crosslinking. These membranes can operate at exceedingly low pressures (2 bar), while maintaining relatively high rejections of multivalent ions. In spite of their great potential, our understanding as to what makes them superior has been limited, demanding further investigation before any large-scale implementation can be realized. In this study, the Donnan-Steric Pore Model with dielectric exclusion (DSPM-DE) is applied for the first time to these membranes to describe the membrane separation performance, and to explain the observed rejection trends, including negative rejection, and their underlying multi-ionic interactions. Experiments were conducted on a spectrum of feed chemistries, ranging from uncharged solutes to single salts, salt mixtures, and artificial seawater to characterize the membrane and accurately predict its performance. Modeling results were validated with experiments, and then used to elucidate the working principles that underlie the low-pressure softening process. An approach based on sensitivity analysis shows that the membrane pore dielectric constant, followed by the pore size, are primarily responsible for the selectively high rejections of the NF membranes to multivalent ions. Surprisingly, the softening process is found to be less sensitive to changes in membrane charge density. Our findings demonstrate that the unique ability of these membranes to exclusively separate multivalent ions from the solution, while allowing monovalent ions to permeate, is key to making this low-pressure softening process realizable.

show abstract

Section: Membrane Characterizationmentioning

confidence: 99%

“…The membrane effective thickness, defined as the ratio of the membrane thickness ∆x to its porosity A k , can be estimated based on the Hagen-Poiseuille equation once an effective pore size is established [26,52].…”

Section: Defining An Effective Membrane Thickness: Pure Water Permeabmentioning

confidence: 99%

Fundamentals of low-pressure nanofiltration: Membrane characterization, modeling, and understanding the multi-ionic interactions in water softening

Labban

Liu

Chong

et al. 2017

Journal of Membrane Science

148

View full text Add to dashboard Cite

show abstract

“…The result reveals that UV-grafting significantly affects the membrane structure parameter (pore size and skin layer thickness) and consequently the membrane performance. The obtained pore size values of all membranes are in the range of commercial NF membrane characteristics [24]. In terms of membrane thin layer thickness, membranes grafted with NVP are thicker than the un-grafted NFPES10.…”

Section: Discussionmentioning

confidence: 66%

“…These hydrodynamics coefficients with a limited range of k (0 < k < 0.95) are well-expressed by Bowen and Mohammad [24] through third-order polynomial equations:…”

Section: Hydrodynamic Model/pmmentioning

confidence: 89%

See 1 more Smart Citation

UV-photografting modification of NF membrane surface for NOM wfouling reduction

Nizam

Hilal

Khayet

2013

Desalination and Water Treatment

View full text Add to dashboard Cite

A B S T R A C TFouling of natural organic matter is one of the common problems in water treatment plant. Despite physical and chemical treatment normally used to recover the flux loss, membrane surface properties also not less important to be considered. In this study, UV-photografting technique was applied to modify commercial nanofiltration (NF) membrane surface in order to reduce fouling tendency. Neutral hydrophilic N-vinylpyrrolidone has been chosen as the monomer for the UV-photografting. The result revealed that the grafted membrane at optimum conditions exhibits low humic acid fouling tendency compared with the unmodified membrane. In addition, both the unmodified and the UV-grafted polyethersulfone NF membranes were characterized in terms of structural properties (pore size, r p, and ratio of membrane thickness to porosity, Dx/A k ) using Pore Model in order to evaluate the effect of UV-photografting modification on structural parameters and indirectly influence the membrane performance and fouling as well.

show abstract

Atomic force microscopy characterization of ultrafiltration membranes: correspondence between surface pore dimensions and molecular weight cut-off

Bowen

Doneva

2000

Surf. Interface Anal.

View full text Add to dashboard Cite

Atomic force microscopy (AFM) has been used to quantify the mean surface pore diameters of a family of five ultrafiltration membranes with molecular weight cut-off (MWCO) in the range 1000-10 000. High aspect ratio tips were used and the images were treated with fast Fourier transform filtering to remove distortions. The mean pore diameters were found to be in the range 1.93-3.14 nm, increasing systematically with the MWCO. Mean pore diameters have also been evaluated from the MWCO values using three published expressions relating MWCO to solute radius. Depending on the expression used, the ratio of the mean pore diameters obtained from MWCO data and AFM measurements (R r ) was in the range 1.04-2.42. Agreement between the diameters obtained in the two ways was best for the membranes with the lowest MWCO values. The overall agreement was substantially better than has been reported previously. The good correspondence between mean surface pore dimensions and MWCO demonstrates the usefulness of AFM in quantifying such a key membrane property.

show abstract

Characterization and Prediction of Nanofiltration Membrane Performance—A General Assessment

Cited by 271 publications

References 16 publications

Fundamentals of low-pressure nanofiltration: Membrane characterization, modeling, and understanding the multi-ionic interactions in water softening

Fundamentals of low-pressure nanofiltration: Membrane characterization, modeling, and understanding the multi-ionic interactions in water softening

UV-photografting modification of NF membrane surface for NOM wfouling reduction

Atomic force microscopy characterization of ultrafiltration membranes: correspondence between surface pore dimensions and molecular weight cut-off

Contact Info

Product

Resources

About