Reverse osmosis desalination: A state-of-the-art review

Qasim, Muhammad; Badrelzaman, Mohamed; Darwish, Naif A.; Hilal, Nidal

doi:10.1016/j.desal.2019.02.008

Cited by 798 publications

(292 citation statements)

References 479 publications

(662 reference statements)

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“…Interfacial polymerization (IP) is the current state‐of‐the‐art for producing thin‐film composite (TFC) membranes . This process produces a tight separation layer of the composite membranes where the selective separation of salts or low molecular weight molecules from a mixed feed is not always feasible.…”

Section: Water Permeance and Molecular Separation Behavior Of The Polmentioning

confidence: 99%

Large Area Self‐Assembled Ultrathin Polyimine Nanofilms Formed at the Liquid–Liquid Interface Used for Molecular Separation

et al. 2020

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Separation membranes with higher molecular weight cut‐offs are needed to separate ions and small molecules from a mixed feed. The molecular sieving phenomenon can be utilized to separate smaller species with well‐defined dimensions from a mixture. Here, the formation of freestanding polyimine nanofilms with thicknesses down to ≈14 nm synthesized via self‐assembly of pre‐synthesized imine oligomers is reported. Nanofilms are fabricated at the water–xylene interface followed by reversible condensation of polymerization according to the Pieranski theory. Polyimine nanofilm composite membranes are made via transferring the freestanding nanofilm onto ultrafiltration supports. High water permeance of 49.5 L m‐2 h−1 bar−1 is achieved with a complete rejection of brilliant blue‐R (BBR; molecular weight = 825 g mol−1) and no more than 10% rejection of monovalent and divalent salts. However, for a mixed feed of BBR dye and monovalent salt, the salt rejection is increased to ≈18%. Membranes are also capable of separating small dyes (e.g., methyl orange; MO; molecular weight = 327 g mol−1) from a mixed feed of BBR and MO. Considering a thickness of ≈14 nm and its separation efficiency, the present membrane has significance in separation processes.

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Section: Water Permeance and Molecular Separation Behavior Of The Polmentioning

confidence: 99%

Large Area Self‐Assembled Ultrathin Polyimine Nanofilms Formed at the Liquid–Liquid Interface Used for Molecular Separation

et al. 2020

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“…Reverse osmosis (RO) and nanofiltration (NF) play a crucial role in the production of potable water from waste, brackish and seawater [1][2][3]. The main active components of RO desalination plants are thin film composite (TFC) membranes composed of three polymeric layers with a total thickness of~140 to~300 µm.…”

Section: Introductionmentioning

confidence: 99%

Morphology of Thin Film Composite Membranes Explored by Small-Angle Neutron Scattering and Positron-Annihilation Lifetime Spectroscopy

Pipich¹,

Dickmann

Frielinghaus³

et al. 2020

Membranes

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The morphology of thin film composite (TFC) membranes used in reverse osmosis (RO) and nanofiltration (NF) water treatment was explored with small-angle neutron scattering (SANS) and positron-annihilation lifetime spectroscopy (PALS). The combination of both methods allowed the characterization of the bulk porous structure from a few Å to µm in radius. PALS shows pores of 4.5 Å average radius in a surface layer of about 4 µm thickness, which become~40% smaller at the free surface of the membranes. This observation may correlate with the glass state of the involved polymer. Pores of similar size appear in SANS as closely packed pores of~6 Å radius distributed with an average distance of~30 Å. The main effort of SANS was the characterization of the morphology of the porous polysulfone support layer as well as the fibers of the nonwoven fabric layer. Contrast variation using the media H 2 O/D 2 O and supercritical CO 2 and CD 4 identified the polymers of the support layers as well as internal heterogeneities.Keywords: detection of the order of Å to micrometer large pores in RO membranes; fibers of nonwoven fabric support layer; chemistry and internal structures; positron-annihilation lifetime spectroscopy; small-angle neutron scattering using contrast variation Thickness of the polyamide skin layer is in the range 0.1 to 0.3 µm, the porous and nonwoven fabric support layers about 40 µm and 100 to 300 µm, respectively.In this paper, we analyze the morphology of several commercial RO and NF membranes from the perspectives of positron-annihilation lifetime spectroscopy (PALS) and small-angle neutron scattering (SANS). Both methods are non-invasive techniques, which usually do not require special sample treatment. PALS measures pores of a few Å radius in the membrane surface layer over a depth of about 3 µm thickness thereby exploring the attendance of micro pores in the whole polyamide skin layer as well as in the outer part of the polysulfone support layer. Thus, PALS delivers relevant structural information of the PA selective layer, which determines water permeability and salt rejection. Neutrons, on the other hand, penetrate the whole membrane, thus characterizing pores and the fibers of the nonwoven fabric of radii between Å and several µm as well as identifying the polymers of the entire membrane.However, the analysis of asymmetric TFC-RO/NF membranes with SANS is complicated and work-intensive as the scattering is strong and locally not specified. These difficulties were largely resolved by corrections for multiple scattering and by performing contrast variation measurements, which allow for identification and a more detailed morphological characterization of the membrane polymers. Scattering from the PA skin layer of the membrane is almost non-detectable with SANS due to its small thickness in comparison with both supporting layers. Only at large scattering angles analogous to large Q the morphology of the PA layer might become visible when scattering from pores of several Å size are dominating. PALS supports t...

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“…Reverse osmosis (RO) is a desalination process that removes salts and minerals from seawater or brackish water with a salinity of total dissolved solids (TDS) of~1000-60,000 mg/L to produce clean water with less than 500 mg/L TDS [1]. The RO process currently produces about 50% of the total desalinated water available worldwide [2]; however, it also yields a huge amount of further concentrated brines (or RO reject water) with over~10,000 mg/L TDS as a waste byproduct.…”

Section: Introductionmentioning

confidence: 99%

“…Currently, all desalination plants (e.g., RO, nanofiltration, multi-stage flash) globally produce 51.7 billion m 3 of concentrated brines every year,~38% of the volume of which is RO reject water (i.e.,~19.6 billion m 3 /year worldwide) [3]. The RO reject water is generally discharged to the sea or local bodies of water, which changes their salinity, alkalinity, and/or water temperature, resulting in significant negative environmental impacts [2]. Thus, various technologies designed to minimize or reuse RO reject water have been developed, such as evaporation and crystallization, forward osmosis, membrane distillation, electrodialysis, and zero discharge desalination; however, all these technologies demand substantial additional costs [2,4,5].…”

Section: Introductionmentioning

confidence: 99%

Recycling of Reverse Osmosis (RO) Reject Water as a Mixing Water of Calcium Sulfoaluminate (CSA) Cement for Brick Production

et al. 2019

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This study explored the possibility of using reverse osmosis (RO) reject water as a mixing water for producing cementitious bricks using calcium sulfoaluminate (CSA) cement along with gypsum, and it investigated the changes in the properties of CSA cement pastes when RO reject water was used. The results were compared with those obtained using purified water and seawater. Overall, the use of RO reject water improved the cement paste’s strength. Given that the use of RO reject water very slightly affected ettringite formation but more significantly influenced the Al2O3-Fe2O3-mono (AFm) phases (i.e., monosulfate, kuzelite, and Friedel’s salt) and amorphous aluminum hydroxide (AH3), the strength improvement was likely mainly due to the formation of Friedel’s salt rather than ettringite formation. This study also demonstrated that the use of RO reject water for brick production satisfied the Korean Standards (KS) F 4004 and toxicity characteristic leaching procedure (TCLP); thus, it is recommended to use RO reject water as a mixing water to produce CSA cement bricks for use in construction.

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Reverse osmosis desalination: A state-of-the-art review

Cited by 798 publications

References 479 publications

Large Area Self‐Assembled Ultrathin Polyimine Nanofilms Formed at the Liquid–Liquid Interface Used for Molecular Separation

Large Area Self‐Assembled Ultrathin Polyimine Nanofilms Formed at the Liquid–Liquid Interface Used for Molecular Separation

Morphology of Thin Film Composite Membranes Explored by Small-Angle Neutron Scattering and Positron-Annihilation Lifetime Spectroscopy

Recycling of Reverse Osmosis (RO) Reject Water as a Mixing Water of Calcium Sulfoaluminate (CSA) Cement for Brick Production

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