Critical aspects of RO desalination: A combination strategy

Imbrogno, Joseph; Keating, John J.; Kilduff, James E.; Belfort, Georges

doi:10.1016/j.desal.2016.06.033

“…[5] Another and more-subtle requirement when comparing the filtration performance of different membranes during liquid filtration is the need to compare the performance for the same volume permeated or on an energy consumption basis. [6] Several exciting new reports on gas separations with membranes,have recently focused on selectivity and in some cases on capacity. [7] However, mass transport (CP,F )a nd scale-up limitations are mentioned but not considered in detail.…”

Section: Three Legsmentioning

confidence: 99%

“…Diagnosing which fouling effect dominates was first reported > 50 years ago for deadended filtration (no crossflow) [46] and more recently for crossflow with two and three mechanisms at constant transmembrane pressure or flux. [6,47] Theu niversal equation and schematics of each fouling type are presented in Fig-…”

Section: Mass Transfer Limitationsmentioning

confidence: 99%

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Membrane Filtration with Liquids: A Global Approach with Prior Successes, New Developments and Unresolved Challenges

Belfort

¹

2018

Self Cite

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After 70 years, modern pressure‐driven polymer membrane processes with liquids are mature and accepted in many industries due to their good performance, ease of scale‐up, low energy consumption, modular compact construction, and low operating costs compared with thermal systems. Successful isothermal operation of synthetic membranes with liquids requires consideration of three critical aspects or “legs” in order of relevance: selectivity, capacity (i.e. permeation flow rate per unit area) and transport of mass and momentum comprising concentration polarization (CP) and fouling (F). Major challenges remain with respect to increasing selectivity and controlling mass transport in, to and away from membranes. Thus, prediction and control of membrane morphology and a deep understanding of the mechanism of dissolved and suspended solute transport near and in the membrane (i.e. diffusional and convective mass transport) is essential. Here, we focus on materials development to address the relatively poor selectivity of liquid membrane filtration with polymers and discuss the critical aspects of transport limitations. Machine learning could help optimize membrane structure design and transport conditions for improved membrane filtration performance.

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“…Omitting one of these “legs” in evaluating the performance capability or in comparing a membrane filtration process with other separation methods gives incorrect and misleading results . Another and more‐subtle requirement when comparing the filtration performance of different membranes during liquid filtration is the need to compare the performance for the same volume permeated or on an energy consumption basis . Several exciting new reports on gas separations with membranes, have recently focused on selectivity and in some cases on capacity .…”

Section: Global Approachmentioning

confidence: 99%

Membrane Filtration with Liquids: A Global Approach with Prior Successes, New Developments and Unresolved Challenges

Belfort

¹

2018

Self Cite

View full text Add to dashboard Cite

After 70 years, modern pressure‐driven polymer membrane processes with liquids are mature and accepted in many industries due to their good performance, ease of scale‐up, low energy consumption, modular compact construction, and low operating costs compared with thermal systems. Successful isothermal operation of synthetic membranes with liquids requires consideration of three critical aspects or “legs” in order of relevance: selectivity, capacity (i.e. permeation flow rate per unit area) and transport of mass and momentum comprising concentration polarization (CP) and fouling (F). Major challenges remain with respect to increasing selectivity and controlling mass transport in, to and away from membranes. Thus, prediction and control of membrane morphology and a deep understanding of the mechanism of dissolved and suspended solute transport near and in the membrane (i.e. diffusional and convective mass transport) is essential. Here, we focus on materials development to address the relatively poor selectivity of liquid membrane filtration with polymers and discuss the critical aspects of transport limitations. Machine learning could help optimize membrane structure design and transport conditions for improved membrane filtration performance.

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“…The modication process may likewise reduce the membrane ux or retention. 19 A more efficient, time-saving and appropriate method for membrane modication is the main development trend now. The g-ray radiation-initiated graing method is very attractive because of its low cost and ease of operation.…”

Section: Introductionmentioning

confidence: 99%

Tailor-made high-performance reverse osmosis membranes by surface fixation of hydrophilic macromolecules for wastewater treatment

Liu

¹

,

Guo²,

Zhang

³

et al. 2019

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Polyamide aromatic (PA) reverse osmosis (RO) membranes are currently the most important materials in the seawater desalination and wastewater treatment industry. This study used hydrophilic macromolecular polyvinylpyrrolidone (PVP) in a PA selective layer to develop a new polyamide thin-film composite (TFC), namely PA-g-PVP RO, which will be used for water treatment. The TFC is prepared via an interfacial polymerisation process, and TFC-based PVP can be transplanted on a PA surface by radiation. PA-g-PVP RO was characterised by ATR-FTIR, SEM, XPS, AFM and contact angle test and then evaluated by determining its permeability, salt retention and antifouling performance, among other properties. Resultsshow that the chemical composition and surface morphology of the polyamide film significantly changed. A PVP brush grafted on an RO membrane surface significantly enhanced the hydrophilicity and antifouling performance of the membrane. When the PVP concentration was increased in an aqueous solution to 2%, the water contact angle of the sacrificial layer of the modified membrane decreased to 24.3 , the fouling recovery ratio to 93.4% and the salt retention increased to 99.5% at a small flux change. This combined technology can also be used for other macromolecules to modify the membrane and study the preparation and modification of ultra-filtration and nano-filtration membranes. Fig. 9 (a) Filtration performance (water fluxs and salt rejections) and (b) separation layer structure (surface roughness and thickness) of the composite membranes by varying the PVP concentration while keeping the irradiation dose (20 kGy) constant.This journal is

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Critical aspects of RO desalination: A combination strategy

Cited by 43 publications

References 193 publications

Membrane Filtration with Liquids: A Global Approach with Prior Successes, New Developments and Unresolved Challenges

Membrane Filtration with Liquids: A Global Approach with Prior Successes, New Developments and Unresolved Challenges

Membrane Filtration with Liquids: A Global Approach with Prior Successes, New Developments and Unresolved Challenges

Tailor-made high-performance reverse osmosis membranes by surface fixation of hydrophilic macromolecules for wastewater treatment

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