scholarly journals Forward Osmosis: A Critical Review

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 404 ◽  
Author(s):  
Mehrdad Mohammadifakhr ◽  
Joris de Grooth ◽  
Hendrik D. W. Roesink ◽  
Antoine J. B. Kemperman
Keyword(s):  
Interfacial Polymerization ◽  
Water Flux ◽  
Forward Osmosis ◽  
High Water ◽  
Structural Parameter ◽  
Selective Layer ◽  
Internal Concentration ◽  
Alternative Approaches ◽  
Planar Geometries ◽  
Dominant Influence

The use of forward osmosis (FO) for water purification purposes has gained extensive attention in recent years. In this review, we first discuss the advantages, challenges and various applications of FO, as well as the challenges in selecting the proper draw solution for FO, after which we focus on transport limitations in FO processes. Despite recent advances in membrane development for FO, there is still room for improvement of its selective layer and support. For many applications spiral wound membrane will not suffice. Furthermore, a defect-free selective layer is a prerequisite for FO membranes to ensure low solute passage, while a support with low internal concentration polarization is necessary for a high water flux. Due to challenges affiliated to interfacial polymerization (IP) on non-planar geometries, we discuss alternative approaches to IP to form the selective layer. We also explain that, when provided with a defect-free selective layer with good rejection, the membrane support has a dominant influence on the performance of an FO membrane, which can be estimated by the structural parameter (S). We emphasize the necessity of finding a new method to determine S, but also that predominantly the thickness of the support is the major parameter that needs to be optimized.

scholarly journals Improving the Structural Parameter of the Membrane Sublayer for Enhanced Forward Osmosis

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 448
Author(s):  
Jin Fei Sark ◽  
Nora Jullok ◽  
Woei Jye Lau
Keyword(s):  
Water Permeability ◽  
Elevated Temperatures ◽  
Interfacial Polymerization ◽  
Water Flux ◽  
Forward Osmosis ◽  
Salt Flux ◽  
Structural Parameter ◽  
Asymmetric Membrane ◽  
S Parameter ◽  
Phase Inversion Technique

The structural (S) parameter of a medium is used to represent the mass transport resistance of an asymmetric membrane. In this study, we aimed to fabricate a membrane sublayer using a novel composition to improve the S parameter for enhanced forward osmosis (FO). Thin film composite (TFC) membranes using polyamide (PA) as an active layer and different polysulfone:polyethersulfone (PSf:PES) supports as sublayers were prepared via the phase inversion technique, followed by interfacial polymerization. The membrane made with a PSf:PES ratio of 2:3 was observed to have the lowest contact angle (CA) with the highest overall porosity. It also had the highest water permeability (A; 3.79 ± 1.06 L m−2 h−1 bar−1) and salt permeability (B; 8.42 ± 2.34 g m−2 h−1), as well as a good NaCl rejection rate of 74%. An increase in porosity at elevated temperatures from 30 to 40 °C decreased Sint from 184 ± 4 to 159 ± 2 μm. At elevated temperatures, significant increases in the water flux from 13.81 to 42.86 L m−2 h−1 and reverse salt flux (RSF) from 12.74 to 460 g m−2 h−1 occur, reducing Seff from 152 ± 26 to 120 ± 14 μm. Sint is a temperature-dependent parameter, whereas Seff can only be reduced in a high-water- permeability membrane at elevated temperatures.

scholarly journals Insights into the Influence of Membrane Permeability and Structure on Osmotically-Driven Membrane Processes

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 153
Author(s):  
Jing Wei ◽  
Qianhong She ◽  
Xin Liu
Keyword(s):  
High Performance ◽  
Water Flux ◽  
Forward Osmosis ◽  
Feed Solution ◽  
Cellulose Triacetate ◽  
Membrane Properties ◽  
Structural Parameter ◽  
Separation Performance ◽  
Membrane Performance ◽  
Internal Concentration

The success of osmotically-driven membrane (OM) technology relies critically on high-performance membranes. Yet trade-off of membrane properties, often further complicated by the strongly non-linear dependence of OM performance on them, imposes important constraint on membrane performance. This work systematically characterized four typical commercial osmotic membranes in terms of intrinsic separation parameters, structure and surface properties. The osmotic separation performance and membrane scaling behavior of these membranes were evaluated to elucidate the interrelationship of these properties. Experimental results revealed that membranes with smaller structural parameter (S) and higher water/solute selectivity underwent lower internal concentration polarization (ICP) and exhibited higher forward osmosis (FO) efficiency (i.e., higher ratio of experimental water flux over theoretical water flux). Under the condition with low ICP, membrane water permeability (A) had dominant effect on water flux. In this case, the investigated thin film composite membrane (TFC, A = 2.56 L/(m2 h bar), S = 1.14 mm) achieved a water flux up to 82% higher than that of the asymmetric cellulose triacetate membrane (CTA-W(P), A = 1.06 L/(m2 h bar), S = 0.73 mm). In contrast, water flux became less dependent on the A value but was affected more by membrane structure under the condition with severe ICP, and the membrane exhibited lower FO efficiency. The ratio of water flux (Jv TFC/Jv CTA-W(P)) decreased to 0.55 when 0.5 M NaCl feed solution and 2 M NaCl draw solution were used. A framework was proposed to evaluate the governing factors under different conditions and to provide insights into the membrane optimization for targeted OM applications.

Enhancing Water Permeability with Super-hydrophilic Metal-Organic Frameworks and Hydrophobic Straight Pores

2021 ◽  
Author(s):  
Mehdi Habibollahzadeh ◽  
Juran Noh ◽  
Liang Feng ◽  
Hong-Cai Zhou ◽  
Ahmed Abdel-Wahab ◽  
...  
Keyword(s):  
Osmotic Pressure ◽  
Water Permeability ◽  
Metal Organic Frameworks ◽  
Water Flux ◽  
Forward Osmosis ◽  
High Water ◽  
Metal Organic

High water flux and salt selectivity have been the most demanding goals for osmosis-based membranes. Osmotic pressure differences across membranes are particularly important in emerging forward osmosis and pressure retarded...

scholarly journals Preparation of defect free TFC FO membranes using robust and highly porous ceramic substrate

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Jincai Su ◽  
Yanyan Wei ◽  
Hui Li
Keyword(s):  
Osmotic Pressure ◽  
Interfacial Polymerization ◽  
Pure Water ◽  
Porous Ceramic ◽  
Water Flux ◽  
Solute Flux ◽  
Structural Parameter ◽  
Solute Permeability ◽  
Draw Solution ◽  
Surface Pores

In this study, robust and defect-free thin film composite (TFC) forward osmosis (FO) membranes have been successfully fabricated using ceramic hollow fibers as the substrate. Polydopamine (PDA) coating under controlled conditions is effective to reduce the surface pores of the substrate and make the substrate smooth enough for the interfacial polymerization. The pure water permeability (A), solute permeability (B) and structural parameter (S) of the resultant FO membrane are 0.854 L·m-2h-1bar-1 (LMH/Bar) 0.186 L·m-2h-1 (LMH) and 1720 µm, respectively. The water flux and reverse draw solute flux are measured using NaCl and proprietary ferric sodium citrate (FeNaCA) draw solutions at low and high osmotic pressure ranges. With increasing the osmotic pressure, higher water flux is obtained but its increase is not directly proportional to the increase in the osmotic pressure. At the membrane surface, the effect of dilutive concentration polarization is much less serious for FeNaCA draw solutions. At an osmotic pressure of 89.6 bar, the developed TFC membrane generates water fluxes of 11.5 and 30.0 LMH using NaCl and synthesized FeNaCA draw solutions. The corresponding reverse draw solute flux is 7.0 g·m-2h-1 (gMH) for NaCl draw solution but it is not detectable for FeNaCA draw solution. This means that the developed TFC FO membranes are defect free and their surface pores are at molecular level. The performance of the developed TFC FO membranes are also demonstrated for the enrichment of BSA protein.

Graphene membranes with nanoslits for seawater desalination via forward osmosis

2017 ◽  
Vol 19 (45) ◽  
pp. 30551-30561 ◽  
Author(s):  
Madhavi Dahanayaka ◽  
Bo Liu ◽  
Zhongqiao Hu ◽  
Qing-Xiang Pei ◽  
Zhong Chen ◽  
...  
Keyword(s):  
Water Flux ◽  
Forward Osmosis ◽  
High Water ◽  
Seawater Desalination ◽  
Graphene Membrane ◽  
Ion Rejection ◽  
Slit Pore ◽  
Graphene Membranes

A slit-pore stacked graphene membrane shows promising forward osmosis performance with high water flux and ion rejection.

Synthesis and Characterization of CTA/CA-Based Forward Osmosis Membranes with Hydrophilic Nano-Titanium Dioxide

2016 ◽  
Vol 867 ◽  
pp. 127-131 ◽  
Author(s):  
Xiu Ju Wang ◽  
Xin Lian Shi ◽  
Shu Fang Hou ◽  
Jian Hua Yang ◽  
Kai Li Zhou ◽  
...  
Keyword(s):  
Pure Water ◽  
Water Flux ◽  
Forward Osmosis ◽  
Bath Temperature ◽  
High Water ◽  
Cellulose Triacetate ◽  
Sem Images ◽  
Salt Rejection ◽  
Pure Water Flux ◽  
Nano Titanium Dioxide

In this paper, a novel nanocomposite forward osmosis membrane (nTiO2-CTA/CA) was fabricated by introducing nanotitaniumdi oxide (nTiO2) into the cellulose triacetate/cellulose acetate (CTA/CA)-based casting solution using phase inversion methods. Casting composite and preparation--nTiO2 content, blend temperature and coagulating bath temperature--were tested for their effects on pure water flux and salt rejection of membranes. Results revealed that the FO membrane prepared under optimized composition showed excellent desalination performance (high water flux = 5.38 L/m2·h and salt rejection > 97 %). Moreover, SEM images showed that addition of nTiO2 resulted in nanocomposite forward osmosis membrane with a smoother surface. The contact angle of the membranes decreased from 76o to 51° with increase nTiO2 concentration from 0% to 0.10%.

Preparation and Characterization of the Tri-Channel Hollow Fiber Charged Mosaic Membrane

2010 ◽  
Vol 150-151 ◽  
pp. 1315-1320 ◽  
Author(s):  
Jian Mian Deng ◽  
Jin Dun Liu ◽  
Hao Qin Zhang ◽  
Ya Tao Zhang ◽  
Dong Cheng
Keyword(s):  
Aqueous Phase ◽  
Organic Phase ◽  
Hollow Fiber ◽  
Interfacial Polymerization ◽  
Xylenol Orange ◽  
Uniform Design ◽  
Water Flux ◽  
Composite Layer ◽  
High Water ◽  
Sulfonate Group

Charged mosaic membrane (CMM) has high water flux, low salt retention and high organic rejection. The tri-channel hollow fiber charged-mosaic membrane (CMM) was prepared by interfacial polymerization (IP). The tri-channel polysulfone (PSF) hollow fiber ultrafiltration(UF) membrane was used as the support membrane. Polyethylenimine (PEI), 2, 5-diamino-benzenesulfonic acid (DIA) and basic fuchsin (BF) were used as aqueous phase monomer. Trimesoyl chloride (TMC) was used as organic phase monomer. ATR-IR, scanning electron microscope (SEM) and gas sorption analyzer (GSA) were applied in structural analysis of CMM. The uniform design and SPSS were applied in membrane preparation and data analysis.The polymer ATR-IR spectroscopy shows IP occurrence between aqueous phase monomer and organic phase monomer. Polymer contains both sulfonate group and quaternary ammonium group. It show that the membrane has the feature of CMM. Regression equation was gained, and it shows the CMM retention would enhance with the concentration increase of DIA, PEI and SDS and decrease with concentration decrease of FB in experimental range. The composite layer can be observed from membrane SEM after IP. The CMM retention to NaCl, polyethylene glycol(PEG), Xylenol orange and Methyl chloride is12.4%, 90%, 96%,88% and 88.2% respectively.

scholarly journals Novel Thin Film Nanocomposite Forward Osmosis Membranes Prepared by Organic Phase Controlled Interfacial Polymerization with Functional Multi-Walled Carbon Nanotubes

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 476
Author(s):  
Xu Zhang ◽  
Jiuhan Zheng ◽  
Lusheng Xu ◽  
Ming Yin ◽  
Guoliang Zhang ◽  
...  
Keyword(s):  
Thin Film ◽  
Carbon Nanotubes ◽  
Organic Phase ◽  
Interfacial Polymerization ◽  
Forward Osmosis ◽  
Structural Parameter ◽  
Transfer Resistance ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Thin Film Nanocomposite

Novel high-quality thin film nanocomposite (TFN) membranes for enhanced forward osmosis (FO) were first synthesized through organic phase controlled interfacial polymerization by utilizing functional multi-walled carbon nanotubes (MWCNTs). As 3-aminopropyltriethoxysilane (APTES) grafted MWCNTs via an amidation reaction significantly promoted the dispersion in organic solution, MWCNTs-APTES with better compatibility effectively restricted the penetration of trimesoyl chloride (TMC), thus adjusting the morphology and characters of TFN membranes. Various techniques such as Fourier transform infrared spectra (FTIR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), sessile droplet analysis and FO experiments and reverse osmosis (RO) operation were taken to characterize and evaluate the performance of nanocomposites and membranes. The prepared TFN FO membranes exhibited good hydrophilicity and separation efficiency, in which water flux was about twice those of thin film composite (TFC) membranes without MWCNTs-APTES in both AL-DS and AL-FS modes. Compared with the original TFC membrane, the membrane structural parameter of the novel TFN FO membrane sharply was cut down to 60.7%. Based on the large number of low mass-transfer resistance channels provided by functional nanocomposites, the progresses may provide a facile approach to fabricate novel TFN FO membranes with advanced selectivity and permeability.

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