For Forward Osmosis Membranes Research Articles

Novel polyelectrolyte-glycol ether ternary phase-separating draw solutions for desalination using forward osmosis

This study systematically evaluated the potential of novel organic draw solutions for forward osmosis (FO) desalination. The formulations included 4 binary and 6 ternary systems incorporating sodium carboxymethyl cellulose (NaCMC) and propylene glycol propyl ether (PGPE). Using a custom-built FO laboratory setup, the experimental water and solute fluxes of the new draw solutions were investigated. The ternary 0.5NaCMC-3.75PGPE draw solution demonstrated an osmotic pressure of 33.9942 bars. When tested at 30 °C, this draw solution yielded average experimental water fluxes of 17.487, 15.654, and 12.482 LMH while desalinating 5000 ppm NaCl brackish feed solutions. Furthermore, scaling up to 0.5NaCMC-20PGPE was effective for seawater desalination, with experimental water fluxes averaging 13.975 and 14.284 LMH against a 35,000 ppm NaCl feed solution. A comprehensive morphological analysis was conducted to evaluate the compatibility of the FO membrane with the organic draw solutions following a 21-day immersion period.

Forward osmosis TFN membrane prepared by adjusting a PDA/GO-Fe3+-TA interlayer on porous CTA substrates

Cellulose triacetate (CTA) is commonly used as the material for forward osmosis (FO) membranes due to its good chlorine resistance, fouling resistance and wide availability. In this work, the implications of various solvents on the appearance and desalination capacity of CTA FO membranes were systematically investigated. CTA membranes with large pore size and high porosity were constructed by using spray-modified non-solvent induced phase separation (s-NIPS). The water flux of CTA membranes fabricated by s-NIPS using DMSO as the solvent was up to 34.4 L m−2h−1, which was 5.6 times higher than HTI commercial membranes, and the reverse salt flux was only 10.9 g m−2h−1. A poly-dopamine (PDA) /graphene oxide (GO) -Fe3+-tannic acid (TA) interlayer was introduced to adjust the cross-linking degree of the polyamide (PA). And thin-film nanocomposite (TFN) membranes (PA-PDA/GO-Fe3+-TA-CTA) were fabricated successfully. The water flux was 35.8 L m−2h−1 and the reverse salt flux decreased to 5.84 g m−2h−1. These experimental results propose an emerging approach to design and develop high performance FO membranes in a rational way.

Fabrication of high-performance forward osmosis membrane based on asymmetric integrated nanofiber porous support induced by a new controlled photothermal induction method

The high surface roughness and large pore size of electrospun nanofibers (ESNF) make it impossible to form good polyamide (PA) layers through interfacial polymerization. Therefore, ESNF cannot be directly used as the supporting layer of nanofiber-supported thin film composite forward osmosis (NTFC-FO) membrane. However, its advantages of high porosity and large pore size are required for forward osmosis (FO) process. In this work, for the first time, an asymmetric integrated ESNF is constructed by introducing photothermal materials PANI into the supporting layer and using in situ photothermal annealing to controllably reduce the surface roughness and pore size of the support membrane, which not only meets the requirements of interface polymerization to form a good PA layer, but also maintains the high porosity, large pore size and structural stability of the ESNF. With this strategy, the FO membrane with highly selective PA layer and low membrane structural parameter (S) were obtained. The results shows that NTFC-FO membrane shows high water flux of 40.2 L·m−2·h−1 and low reverse salt flux of 4.9 g·m−2·h−1, and specific salt flux of Js/Jw is only 0.12 with deionized water and 1.0 M NaCl solution as the feed solution and draw solution, respectively, and the FO membrane also exhibit excellent rejection to dye wastewater. It can be considered that the asymmetric integrated ESNF supporting layer constructed by the photothermal annealing strategy provides a simple and feasible method for the preparation of high-performance NTFC-FO membranes.

Fouling-resistant surface modification of forward osmosis membranes using MoS2-Ag nanofillers

The mitigation of organic fouling is a main challenge for forward osmosis (FO) technology. In order to enhance the fouling resistance and desalination efficiency of the FO membrane, various studies have suggested the incorporation of nanomaterials into thin-film composite (TFC) membranes, which are defined as thin-film nanocomposite (TFN) membranes. In this study, we fabricated MoS2-Ag nanofillers by photochemical deposition method and incorporated them into TFC membranes for FO water treatment. After incorporation of MoS2-Ag nanofillers into TFC membranes, we could observe significant change in the surface of membranes. Especially, active layer surface of TFN membrane was smoothened, which was represented by decrease of roughness from 40.09 ± 1.39 nm of TFC membrane to 15.53 ± 0.17 nm of TFN membrane. Furthermore, according to the hydrophilic surface modification, contact angle of membranes was also decreased from 79.0 ± 2.0° of TFC membrane to 52.2 ± 0.7° of TFN membrane. The surface modification of the TFN membrane resulted in improvement of desalination capacity in terms of 35.2% improved water flux. Finally, the resistance to alginate fouling of TFN membrane was realized and it exhibited almost 4 times lower water flux loss than TFC membrane. This study presents that photochemically synthesized nanofillers could modify the surface of TFN membrane, therefore, this technique can be a feasible approach to future membrane-based technologies.

Chromium-containing wastewater reclamation via forward osmosis with sewage sludge ash temperature-sensitive hydrogel as draw agent

A temperature-sensitive hydrogel modified with sewage sludge ash (SSA) was used as an advanced draw agent for forward osmosis (FO) application in treating chromium-containing wastewater. The performance of the modified hydrogel (SSA-TSH) was measured in terms of the swelling and deswelling properties, as well as adsorption and desorption effects on Cr(VI), chemical oxygen demand (COD), total phosphorous (TP) and ammonium (NH4+-N) in chromium-containing wastewater. Furthermore, the efficiencies of wastewater treatment, water flux, and the reusability of the SSA-TSH as draw agent in the FO process (FO-SSA-TSH) using a commercially available thin-film composite membrane (Sterlitech) were also investigated. The results indicated that FO-SSA-TSH achieved high removal rates of pollutants (Cr(VI): 96.9 %–97.4 %, COD: 97.1 %–97.4 %, TP: 97.7 %–99.6 %, and NH4+-N: 76.8 %–77.9 %) in various Cr(VI) concentrations (0– 40 mg/L) due to the high rejection rate of FO membrane and notable adsorption capacity of the hydrogel. Moreover, the average water flux of FO-SSA-TSH (1.95– 2.02 LMH) was nearly twice as much as that of the FO with pure temperature-sensitive hydrogel as draw agent (FO-TSH, 1.33– 1.42 LMH) in 24 h chromium-containing wastewater treatment. In addition, SSA-TSH with excellent deswelling property exhibited high water recovery performance and good reusability in low cost and energy consumption after the FO permeation process for wastewater treatment.

Polyamidoamine and carboxylated cellulose nanocrystal grafted antifouling forward osmosis membranes for efficient leachate treatment via integrated forward osmosis and membrane distillation process

Organic fouling remains an intractable challenge for forward osmosis (FO) and integrated FO-membrane distillation (MD) strategy to treat landfill leachate. To address this challenge, polyamidoamine (PAMAM)/polydopamine (PDA) and carboxylated cellulose nanocrystal (CCN) were grafted gradually on the commercial thin film composite (TFC) FO membranes via chemical coupling to achieve excellent antifouling capacity. PAMAM dendrimers, with abundant terminal amines, hyperbranched structure and open interior cavity, served as a unique intermediate platform for chemically covalent attachment of CCN with high water affinity, then cooperated with CCN to form a hydrophilic and robust antifouling layer. Compared to the raw TFC membrane, the PAMAM/PDA-CCN modified TFC membrane exhibited a similar water flux of 30.6 L m−2 h−1 (LMH) accompanied with a decreased reverse salt flux of 6.9 g m−2 h−1 (gMH) by using 1 M NaCl solution as draw solution (DS) and DI water as feed solution (FS). When actual leachate was used as FS, the modified FO membranes possessed significantly enhanced antifouling capacity with a lower flux decline (≤43.7%) and a higher flux recovery rate (≥94.2%) than the raw TFC membrane (flux decline ≤59.4% and flux recovery rate ≥79.0%, respectively). The improved fouling resistance could be further demonstrated by the reduced thickness of the organic fouling layer. Eventually, the employment of the modified FO membranes improved the compatibility of the FO and MD water fluxes and achieved sustained water production. The construction of synergistic dendritic PAMAM and CCN grafted surface paves a new way for the development of high-performance water treatment membranes.

Antibacterial and desalting behavior of forward osmosis membranes engineered with metal ions

The current Covid-19 aggravates membrane biofouling issue caused by bacteria and viruses which are widely present in water. Herein we synthesized a series of polyamide (PA)-based membranes engineered with distinct metal ions (Cu2+, Fe3+) via one-step metal-ligand ligation for forward osmosis (FO) separation. The antibacterial and desalting behavior of membrane were investigated by systematically varying the influential factors including the charge status, complexation ability and antibacterial mechanism of metal ions as well as testing conditions. All the newly synthesized membranes exhibit better performance with markedly increased water permeability and selectivity. Therein the Fe3+ − membrane increases water fluxes by 93% (FO mode) and 112% (PRO mode) relative to the nascent PA membrane with 0.5 M NaCl as the draw solution. Both Cu2+ and Fe3+ on membrane surface dramatically improve the membrane bactericidal efficacy against Escherichia coli via destroying the bacterial phospholipid layer. Remarkably, the metal ions on membrane surface are easily regenerated after being consumed by bacteria by simply immersing the membranes into the corresponding nitrate solutions. The separation performance and antibacterial properties of the regenerated membranes are comparable to those of the fresh membranes. When using brine from reverse osmosis process as the draw solution, the Fe3+ membrane recovers water from brackish water up to 70% higher than the nascent PA membrane. This study provides a practical strategy to develop FO membrane with sustainable antibacterial activity and desalination performance.

Thin Film Biocomposite Membrane for Forward Osmosis Supported by Eggshell Membrane.

There is a general drive to adopt highly porous and less tortuous supports for forward osmosis (FO) membranes to reduce internal concentration polarization (ICP), which regulates the osmotic water permeation. As an abundant waste material, eggshell membrane (ESM) has a highly porous and fibrous structure that meets the requirements for FO membrane substrates. In this study, a polyamide-based biocomposite FO membrane was fabricated by exploiting ESM as a membrane support. The polyamide layer was deposited by the interfacial polymerization technique and the composite membrane exhibited osmotically driven water flux. Further, biocomposite FO membranes were developed by surface coating with GO for stable formation of the polyamide layer. Finally, the osmotic water flux of the eggshell composite membrane with a low structural parameter (~138 µm) reached 46.19 L m−2 h−1 in FO mode using 2 M NaCl draw solution.

Ferric hydroacid & diamine complex as draw solute for forward osmosis (FO) desalination processes

Forward osmosis (FO) is being one of the recent technologies widely studied for desalination. FO mainly uses osmotic pressure gradient unlike reverse osmosis (RO) that uses hydraulic pressure gradient. So increasing the osmotic pressure is highly influencing the water flux in FO systems. A new type of draw solute used for enhancing the FO process is mixed ligand PDA-Fe-CA complex (Ferric hydroacid & diamine). Mixed ligand PDA-Fe-CA complex is a complex from iron–citric complex (Fe-CA) functionalized by 1,2phenylenediamine ligand. The resulting complex suggested structure was investigated by FTIR, elemental analysis, and spectrophotometric analysis proving the successful coordination of 1,2phenylenediamine to Fe, besides the successful coordinating of citric acid to Fe. The molar ratio for this complex was found to be 1:1:2 of Fe: CA: PDA. The performance of the produced complex was investigated using commercial FO membranes in batch FO system. 40 g/L (0.06 M) of PDA-Fe-CA produces water flux of 21.5 LMH when tested with distilled water as feed solution, and water flux values of 18, 15.8, 14, and 12.3 L/m2hr were gained when saline water were used as feed solution with concentrations of 3,000, 7,000, and 12,000 mg/L respectively. And the water flux was 7.9 LMH when synthetic sea water (35,000 mg/L NaCl) was used as feed solution.

Recycled reverse osmosis membranes for forward osmosis technology

An alternative use of end-of-life reverse osmosis (RO) membranes is proposed for forward osmosis (FO) application as recycled FO (RFO) membranes and transformed recycled FO (TRFO) membranes. Different passive cleaning protocols in pilot plant and laboratory scale were followed using sodium hypochlorite (NaClO) at different concentrations and exposure time. The RFO with the best performance was selected for its transformation by interfacial polymerization (IP) technique to improve further the FO performance. Both the morphological structure and transport properties of the RFO and TRFO membranes were studied by means of different characterization techniques. Although the RFO membranes are suitable for FO, the TRFO membranes are more competitive. The highest FO water permeate fluxes (12.21 kg/m2·h and 15.12 kg/m2·h) were obtained for the membrane recycled applying the highest NaClO exposure dose applied in pilot plant (106 ppm·h) followed by IP of a thin polyamide layer. These permeate fluxes were better or at least comparable to commercial membranes used under the same FO conditions. The results indicated that it is possible to use discarded RO membranes in FO technology for wastewater treatment after adequate treatment procedures extending their lifetime and contributing to a circular economy and sustainability in membrane science and related materials.

Effect of the different layered structural modification on the performances of the thin-film composite forward osmosis flat sheet membranes – A review

Usually, membrane performances are primarily motivated by the surface morphology. The morphological structure of the thin-film composite (TFC) membrane presents new potential applications for forward osmosis (FO) activities. In this review, the effect of different layered structural modifications on the activities of the TFC-FO flat sheet membranes was reviewed, highlighting several membranes layered frameworks along with the literature evidence. Also, we thoroughly investigated how the morphological properties including surface porosity, pore size, thickness and roughness influence the performance of FO membranes. This review paper concluded that the porosity, tortuosity, membrane thickness, surface roughness, water flux, salt rejection and reverse salt fluxes were altered by different layered structural modifications on the FO membranes. In addition, layer-by-layer (LbL) surface modified TFC-FO membranes helps to (i) prevent the direct contact of the skin and support layers, (ii) minimized the water transport resistance and increased the membrane selectivity, (iii) improved the water flux and solute rejection and (iv) reduced the structural parameter (S-value) and the internal concentration polarization (ICP).

Assessment of physicochemical performance of draw compounds for desalination using multi-criteria analysis

The development of draw compounds for forward osmosis (FO) has been an active area of research. While a few studies have considered draw solutes for FO desalination, these are rarely presented with consistent units for objective performance comparison. To rectify this lack of knowledge, this study objectively compares draw solutes using a multi-criteria analysis (MCA) across a range of physicochemical properties (in consistent units), along with their flux performance when integrated with FO membranes. This analysis reveals that Ionic liquids (IL) have favorable physicochemical characteristics and generally higher flux performance in both nonresponsive and thermally responsive draw solute classes. In particular, magnesium chloride was found to be the optimal non-responsive draw solute. In addition, a diammonium cation-based iodide salt and an oligomer of choline chloride and an itaconic acid mixture were found to achieve the highest water flux of ~15LMH when treating seawater level salinity solutions within thermally responsive draw compounds. The MCA also revealed that hydrogels—particularly those based on poly(N-isopropylacrylamide) (PNIPAM)—are promising because they have the best dewatering capability but suffers from low water flux. Overall, we conclude that IL draw solutions and PNIPAM-based hydrogels represent some of the most promising FO draw compounds for future research.

Fabrication of asymmetric cellulose acetate/pluronic F-127 forward osmosis membrane: minimization of internal concentration polarization via control thickness and porosity

The core of this study was fabrication of novel cellulose acetate/pluronic F-127 (CA/PF-127) composite membranes for forward osmosis (FO) applications. Performance and structure of the FO membranes under the influence of different applicator clearance gaps (ACGs) along with PF-127 wt.% contents were examined during the non-solvent phase separation (NIPS) method. Scanning electron microscopy, water contact angle, atomic force microscopy and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) analysis were used to characterize the membrane properties. The best performance was attributed to the lower thickness and the higher porosity. The lower structural parameter, which reduces the internal concentration polarization (ICP), led to the highest water flux. The values of 10.58 (L/m2.h) and 0.39 (g/L) were obtained as water flux and specific reverse salt flux (SRSF) of the optimal FO membrane, which was synthesized by 20 wt.% of CA, 79.00 wt.% of N-methyl-2-pyrrolidone (NMP), 1.0 wt.% of PF-127 and 100 µm of ACG, respectively.

Forward osmosis with direct contact membrane distillation using tetrabutylphosphonium p-toluenesulfonate as an effective and safe thermo-recyclable osmotic agent for seawater desalination

A phosphonium-based ionic liquid (IL) with lower critical solution temperature (LCST) property was assessed as a reusable draw solution (DS) for forward osmosis (FO). Tetrabutylphosphonium p-toluenesulfonate ([P4444]TsO) was successfully synthesized by neutralization reaction. Characterization results reveal its ability to generate sufficient osmotic pressure (14–68 bars for 0.5–2 M DS) to create a gradient across the FO membrane. Its thermal, physico-chemical and other colligative properties are favorable for its application as an osmotic agent. The LCST behavior of [P4444]TsO was found reversible and its phase separation from water can be done above its cloud point temperature Tc ∼57 °C. In vitro cytotoxicity tests from LDH and MTT assay reveal that it can be safely used as DS at an effective concentration EC30 ∼57 mg L−1 as its non-toxic level. Results from FO operations demonstrate that 2 M [P4444]TsO DS can effectively treat saline feed like seawater (0.6 M NaCl) with reasonable Jv = 1.35 ± 0.15 L m−2h−1, low Js = 0.0038 ± 0.00049 mol m−2h−1, and considerably low specific solute flux (Js/Jv ∼ 0.0028 mol L−1). After FO, ∼98% of [P4444]TsO was precipitated by heating the DS at 60 °C and conveniently reused with consistent FO performance. Direct contact membrane distillation (DCMD) was found effective in removing the residual 2% [P4444]TsO in the DS supernatant to finally produce high-quality effluent with concentrations way below the EC30 limit. Cost estimates for the entire process reveal the potential of FO combined with thermo-cyclic [P4444]TsO regeneration with DCMD for desalination application.

Preparation and characterization of high-performance electrospun forward osmosis membrane by introducing a carbon nanotube interlayer

Electrospun nanofibrous mats have been widely used as substrate to develop novel membranes for forward osmosis (FO) application due to its ultralow structure parameter (S). However, their large pore sizes usually hinder the formation of satisfied active layer. In this work, a novel composite FO membrane was designed and prepared with a carbon nanotubes (CNTs) interlayer between the dense polyamide (PA) layer and electrospun porous polyacrylonitrile (PAN) support layer. The presence of CNT interlayer minified the pore size of the substrate to provide a better platform for PA layer growth which inhibited the diffusion of the draw solute, thus keeping a stable osmosis pressure gradient on both side of the thin-film composite (TFC) membrane. The results revealed that the optimized FO membrane with CNTs interlayer exhibited water flux of 83.55% higher and reverse salt flux of 75.58% lower than the unmodified membrane in the active layer facing draw solution (AL-DS) mode. Such better overall FO performance suggested that the addition of CNTs interlayer would offer a promising avenue to prepare high-performance electrospinning-based FO membrane for practical application.

Engineering a Nanocomposite Interlayer for a Novel Ceramic-Based Forward Osmosis Membrane with Enhanced Performance.

Rational design of a high-performance defect-free polyamide (PA) layer on a robust ceramic substrate is challenging for forward osmosis (FO) water treatment applications. In this study, we first demonstrated a robust ceramic-based thin-film composite (TFC) FO membrane by engineering a novel nanocomposite interlayer of titanium dioxide and carbon nanotube (TiO2/CNT). The structural morphologies and properties were systematically characterized for different substrates (without interlayer, with TiO2 interlayer, or with TiO2/CNT interlayer) and the corresponding ceramic-based TFC-FO membranes. Introduction of low roughness nanocomposite interlayers with decreased pore size created an interface with improved surface characteristics, favoring the formation of a defect-free nanovoid-containing PA layer with high cross-linking degree. The resulting ceramic-based FO membrane had a water permeability of approximately 2 L/(m2 h bar) and a NaCl rejection of 98%, showing simultaneous enhancements in both compared to the control membrane without an interlayer. Mechanism analysis indicates that such a special nanocomposite interlayer not only provided more active sites for the formation of a thinner defect-free nanovoid-containing PA layer without penetration into substrate but also acted as a highly porous three-dimensional network structure for rapid water transport. This work provides a novel protocol for rational design and fabrication of a high-performance multilayered inorganic FO membrane as well as extended applications in water treatment with enhanced performance.

Graphene Oxide Incorporated Forward Osmosis Membranes With Enhanced Desalination Performance and Chlorine Resistance.

In this work, grapheme oxide (GO) nano-sheets were synthesized and dispersed in the aqueous phase for the interfacial polymerization (IP) process to develop a new type of thin-film composite (TFC) membranes for forward osmosis (FO) applications. The effects of the GO concentrations on the membrane surfaces and cross-sectional morphologies and FO desalination performances of the as-prepared TFC membranes were investigated systematically. Compared with the control membrane, the optimal GO-incorporated TFC membrane displayed higher water flux, less specific reverse solute flux (SRSF) and lower structure parameter. Moreover, the optimized membrane showed 75.0 times higher chlorine resistance than the control membrane. In general, these new type of membranes could be an effective strategy to fabricate high-performance FO membranes with good desalination performance and chlorine resistance.

Defect-free outer-selective hollow fiber thin-film composite membranes for forward osmosis applications

This study presents the successful fabrication of a novel defect-free outer-selective hollow fiber (OSHF) thin-film composite (TFC) membrane for forward osmosis (FO) applications. Thin and porous FO membrane substrates made of polyether sulfone (PES) with a dense and smooth outer surface were initially fabricated at different air-gap distances. A modified vacuum-assisted interfacial polymerization (VAIP) technique was then successfully utilised for coating polyamide (PA) layer on the hollow fiber (HF) membrane substrate to prepare OSHF TFC membranes. Experimental results showed that the molecular weight cut-off (MWCO) of the surface of the membrane substrate should be less than 88 kDa with smooth surface roughness to obtain a defect-free PA layer via VAIP. The FO test results showed that the newly developed OSHF TFC membranes achieved water flux of 30.2 L m−2 h−1 and a specific reverse solute flux of 0.13 g L−1 using 1 M NaCl and DI water as draw and feed solution, respectively. This is a significant improvement on commercial FO membranes. Moreover, this OSHF TFC FO membrane demonstrated higher fouling resistance and better cleaning efficiency against alginate-silica fouling. This membrane also has a strong potential for scale-up for use in larger applications. It also has strong promise for various FO applications such as osmotic membrane bioreactor (OMBR) and fertilizer-drawn OMBR processes.

Recent advances in nanomaterial-modified polyamide thin-film composite membranes for forward osmosis processes

Polyamide thin-film composite (PA TFC) membranes have attained much attention for forward osmosis (FO) applications in separation processes, water and wastewater treatment due to their superior intrinsic properties, such as high salt rejection and water permeability compared to the first-generation cellulose-based FO membranes. Nonetheless, several problems like fouling and trade-off between membrane selectivity and water permeability have hindered the progress of conventional PA TFC FO membranes for real applications. To overcome these issues, nanomaterials or chemical additives have been integrated into the TFC membranes. Nanomaterial-modified membranes have demonstrated significant improvement in their anti-fouling properties and FO performance. In addition, the PA TFC membranes can be designed for specific applications like heavy metal removal and osmotic membrane bioreactor by using nanomaterials to modify their physicochemical properties (porosity, surface charge, hydrophilicity, membrane structure and mechanical strength). This review provides a comprehensive summary of the progress of nanocomposite PA TFC membrane since its first development for FO in the year 2012. The nanomaterial-incorporated TFC membranes are classified into four categories based on the location of nanomaterial in/on the membranes: embedded inside the PA active layer, incorporated within the substrate, coated on the PA layer surface, or deposited as an interlayer between the substrate and the PA active layer. The key challenges still being confronted and the future research directions for nanocomposite PA TFC FO are also discussed.

Evaluation of ethanol as draw solute for forward osmosis (FO) process of highly saline (waste)water

In the study, ethanol was evaluated for its potential as a draw solution in forward osmosis (FO) in terms of performance for treating highly saline (waste)waters and energy requirements for regeneration. When compared to NH4HCO3 (a thermolytic draw solution) ethanol exhibited significantly higher osmotic pressure and significantly easier regeneration. In FO experiments using commercial TFC FO membranes, the ethanol draw solution exhibited a water flux comparable to that of NH4HCO3 at equivalent osmotic pressure albeit a relatively high reverse solute flux (RSF) due to its volatility. The modeling prediction based on membrane transport properties obtained from the FO experiments revealed the critical role of the ethanol permeability of the membrane in the overall FO performance, thereby suggesting the necessity of a higher water-ethanol selective membranes for the extensive application of the ethanol draw solution for the treatment of highly saline wastewater. Easy-regeneration of the ethanol draw solution was also demonstrated based on experimental results obtained using laboratory scale vacuum distillation at room temperature and exergy analysis of the integrated system. The results indicated that the regeneration process required an estimated 8.8 kWh/m3, thereby supporting the feasibility of ethanol as a potent draw solution for FO application of highly saline waters.