Thin-film Nanocomposite Forward Osmosis Membrane Research Articles

Lignosulfonate-Coated ZIF-8 as an Effective Nanofiller to Prepare High-Performance Thin-Film Nanocomposite Forward Osmosis Membrane for Heavy Metal Ions Removal

Lignosulfonate-Coated ZIF-8 as an Effective Nanofiller to Prepare High-Performance Thin-Film Nanocomposite Forward Osmosis Membrane for Heavy Metal Ions Removal

Effect of titanium oxide/reduced graphene (TiO2/rGO) addition onto water flux and reverse salt diffusion thin-film nanocomposite forward osmosis membranes

Thin-film nanocomposite (TFN) forward osmosis (FO) membranes have attracted significant attention due to their potential for solving global water scarcity problems. In this study, we investigate the impact of titanium oxide (TiO2) and titanium oxide/reduced graphene (TiO2/rGO) additions on the performance of TFN-FO membranes, specifically focusing on water flux and reverse salt diffusion. Membranes with varying concentrations of TiO2 and TiO2/rGO were fabricated as interfacial polymerizing M-phenylenediamine (MPD) and benzenetricarbonyl tricholoride (TMC) monomers with TiO2 and its reduced graphene composites (TiO2/rGO). The TMC solution was supplemented with TiO2 and its reduced graphene composites (TiO2/rGO) to enhance FO performance and reverse solute flux. All MPD/TMC polyamide membranes are characterized using various techniques such as scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle measurements. The results demonstrate that incorporating TiO2/rGO into the membrane thin layer improves water flux and reduces reverse salt diffusion. In contrast to the TFC membrane (10.24 L m−2h−1 and 6.53 g/m2 h), higher water flux and higher reverse solute flux were detected in the case of TiO2and TiO2/rGO-merged TFC skin membranes (18.81 and 24.52 L m−2h−1 and 2.74 and 2.15 g/m2 h, respectively). The effects of TiO2 and TiO2/rGO stacking on the skin membrane and the performance of TiO2 and TiO2/rGO skin membranes have been thoroughly studied. Additionally, being investigated is the impact of draw solution concentration.Graphical

Electro-forward osmosis through a titanium-dioxide-modified membrane to enhance aquaculture wastewater recovery

In this study, thin-film-nanocomposite forward-osmosis membranes (TFC-FOMs) were assembled with the top polyamide layer being modified by using titanium dioxide (TiO2) nanoparticles with camphorsulfonic acid and triethylamine (CT) agents to enhance the separation performance and surface hydrophilicity. The TFC-FOMs were characterized and tested for aquaculture wastewater (AWW) recovery in a bench-scale FO system and a multilayer electro-FO (e-FO) system, respectively. Results show that the CT modified FOM had the highest selectivity, followed by the CT-TiO2 modified FOM. A considerably lower reverse solute flux (RSF) and higher permeate flux were achieved in the separation of the electrolyte from the draw feed or solution under the bipolar membrane (BPM)–BPM modes and anion-exchange-membrane (AEM)–cation-exchange-membrane (CEM). When the CT FOM was used in the e-FO system worked in the AEM–CEM mode under a voltage of 1.5 V, the water production degree reached 711.5 L m−2 in continuous AWW recovery for 6 days, and the energy consumption considerably decreased as the number of membrane sheets was raised from 1 to 4. Overall, the consequences indicated the technical viability of the designed e-FO system for achieving high and stable separation efficiency and low energy consumption in long-duration AWW recovery. Thus, this system shows promise for practical field applications.

Novel Thin-Film Nanocomposite Forward Osmosis Membranes Modified with WS2/CuAl LDH Nanocomposite to Enhance Desalination and Anti-fouling Performance

Designing efficient membranes for desalination to help reduce the water shortage crisis has been the subject of various studies. In this study, first, CuAl LDH nanosheets were prepared and the surface of some thin-film composite (TFC) membranes was modified by them. Afterward, the novel heterostructure nanocomposite consisting of CuAl LDH and WS2 nanosheets was synthesized by hydrothermal method, and a new kind of thin-film nanocomposite (TFN) membranes were made using them. All the obtained membranes performance was studied in the forward osmosis (FO) process. The effects of the prepared compounds on the morphology, chemical structure, hydrophilicity, and topology of the polyamide (PA) active layer were evaluated by scanning electron microscopy (SEM), FT-IR spectroscopy, energy-dispersive X-ray (EDX), powder x-ray diffraction (XRD), water contact angle (WCA) goniometer and atomic force microscope (AFM) analysis. Finally, by comparing the results for both types of modified membranes, the membrane containing 0.025 wt% of the nanocomposite modifier showed the highest water flux (29.30 LMH) and selectivity (0.38 g/L) that was chosen as the optimal membrane. Also, the anti-fouling properties of this membrane were studied and the obtained results showed an increase in the fouling resistance compared to the membrane without filler.

Polyacrylamide-grafted zinc oxide (ZnO-g-PAM) nanoparticles as a promising nanofiller for thin-film nanocomposite forward osmosis membranes

Polyacrylamide-grafted zinc oxide (ZnO-g-PAM) nanoparticles as a promising nanofiller for thin-film nanocomposite forward osmosis membranes

Thin-Film Nanocomposite Forward Osmosis Membranes Prepared on PVC Substrates with Polydopamine Functionalized Zr-Based Metal Organic Frameworks

Thin-Film Nanocomposite Forward Osmosis Membranes Prepared on PVC Substrates with Polydopamine Functionalized Zr-Based Metal Organic Frameworks

Thin-film nanocomposite forward osmosis membrane for water desalination: synthesis, characterization and performance improvement

Abstract The major scope of this study is the fabrication and development of a substrate and polyamide rejection layer for an efficient thin-film hydrophilic composite forward osmosis (TFC-FO) membrane. Fabrication of a thin-film nanocomposite forward osmosis membrane employing interfacial polymerization and modification of substrate characteristics using titanium dioxide (TiO2) nanoparticles as additives (TFNC-FO) are studied. Characterizations of the prepared TFC-FO and TFNC-FO membranes were determined. The morphologies of cross-section, upper and bottom surfaces for the TFC-FO and TFNC-FO membranes were studied using scanning electron microscopy (SEM). Energy-dispersive X-ray (EDX) spectroscopy was used to examine the compositions of different elements for both membranes. The hydrophilicity of the prepared TFC-FO and TFNC-FO membranes was investigated using the measurement of the contact angle test. A Fourier Transform Infrared (FT-IR) spectrophotometer was used to observe the existing functional groups of the TFC-FO and TFNC-FO membranes. The thermal stability of the membrane was evaluated via thermogravimetric analysis (TGA). The overall performance of TFC-FO membranes was evaluated with and without adding TiO2 nanoparticles through different parameters, such as membrane flux, initial feed concentration, draw solution concentrations, reverse solute fluxes, membrane permeabilities, and finally, the effect of FO membrane orientations. FO membrane performance was successfully enhanced by adding different concentrations of TiO2 nanoparticles from 0.5 to 1.5 wt%. The findings indicated that an increase in the concentration from 0.5 to 1 wt% leads to a clear increase in both the porosity and hydrophilicity of the nanocomposite substrate and consequently, an increase in the water flux. However, further increasing the concentration of TiO2 nanoparticles to more than 1 wt% affects the membrane performance.

Surface modification of thin-film nanocomposite forward osmosis membrane with super-hydrophilic MIL-53 (Al) for doxycycline removal as an emerging contaminant and membrane antifouling property enhancement

• This work is the first study on the incorporation of MIL-53 (Al) into a TFN-FO membrane. • TFN 0.2 membrane showed the highest water flux without losing the selectivity. • Considerably boosted hydrophilicity (contact angle 20.6° vs. 80.4°) was attained. • Doxycycline rejection was obtained up to 99.73% in 2 h. • 96.67% flux recovery ratio was achieved in the filtration of BSA solution. As a contaminant of emerging concern, doxycycline is an antibiotic that has recently drawn rising attention due to its satisfactory outcomes for the treatment of COVID-19. In this study, a novel metal–organic framework thin-film nanocomposite forward osmosis (MOF-TFN FO) membrane was developed for doxycycline removal. The lack of applied hydraulic pressure in FO suggests an energy-efficient and low-cost process. A total of five composite membranes with different MIL-53 (Al) loadings (0, 0.1, 0.2, 0.3, and 0.5 wt%) were fabricated and characterized to assess the effect of MOF incorporation on the physicochemical properties of TFN membranes. Atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM) analysis implied that incorporating MIL-53 (Al) in the polyamide selective layer affects the membrane morphology. Water contact angle measurements indicated significant augmentation in the hydrophilicity of modified membranes (20.6° for the optimally modified membrane vs. 80.4° for the unmodified membrane) owing to the increased hydroxyl group in the membrane selective layer. Due to the reduced structural parameter, the optimized membrane exhibited 94.31% enhanced water flux than the unmodified membrane without losing the selectivity. Also, the fouling experiments with organic foulant allude to the prominent antifouling property of this modified membrane with a 96.67% flux recovery ratio. More notably, the optimized membrane could maintain a high and stable rejection for doxycycline (>98.5%) for 10 h due to its size exclusion and adsorption properties. Our findings reveal the promising results of TFN FO membranes containing MOFs for antibiotics removal, which is not addressed sufficiently in the literature.

Zwitterion-functionalized MIL-125-NH2-based thin-film nanocomposite forward osmosis membranes: towards improved performance for salt rejection and heavy metal removal

Incorporating zwitterion-functionalized MIL-125-NH2nanoparticles in the rejection layer of TFN FO membranes improves their water/ion separation performance and antifouling ability.

High-Performance Thin-Film nanocomposite forward osmosis membranes modified with Poly(dopamine) coated UiO66-(COOH)2

• Surface functionalization of UiO-66 with polydopamine (UiO-PDA). • Thin film nanocomposite (TFN) forward osmosis (FO) membranes were fabricated by incorporating UiO-PDA. • UiO-PDA as a hydrophilic nanomaterial enhanced the separation performance of TFN-FO membranes. • The UiO-PDA modified TFN membrane exhibited better anti-fouling performance and Cu +2 ions rejection in comparison with bare TFC one. In this study, a new family of thin-film nanocomposite forward osmosis (TFN-FO) membranes was synthesized by embedding polydopamine (PDA) coated UiO-66-(COOH) 2 (UiO-PDA) nanofiller in polyamide (PA) rejection layer via interfacial polymerization (IP). The PDA coating assisted the UiO dispersion in MPD/water media, resulting in better chemical miscibility between the UiO-PDA and PA matrix. The impact of the UiO-PDA incorporation on the physicochemical properties (surface chemical composition, hydrophilicity, morphology, and roughness) of the TFN membranes are systematically examined via different characterization techniques. Besides, the effect of UiO-PDA concentration on the overall performances (FO water flux, reverse salt flux, antifouling tendency) of the obtained UiO-PDA modified TFN-FO membranes were investigated in a cross-flow FO system. Compared with the pristine thin film composite (TFC) membrane, the modified TFN membranes presented higher selectivity, water flux, and anti-fouling tendency. Finally, the TFN-UC.2 (modified with 0.03 wt% UiO-PDA) membrane exhibited greater Cu 2+ ions removal in FO mode (feed solution in contact with PA active layer) than the control TFC membrane, arising from their improved PA rejection layer characteristics.

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

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.

Development of CA-TiO2-incorporated thin-film nanocomposite forward osmosis membrane for enhanced water flux and salt rejection

Development of CA-TiO2-incorporated thin-film nanocomposite forward osmosis membrane for enhanced water flux and salt rejection

Effect of graphene oxide quantum dots on the interfacial polymerization of a thin-film nanocomposite forward osmosis membrane: An experimental and molecular dynamics study

We report an ultra-low loading of graphene oxide quantum dots (GQDs) into the polyamide (PA) layer of an outer-selective hollow fiber (OSHF) thin-film composite (TFC) membrane using the vacuum-assisted interfacial polymerization (VAIP) technique to improve the water permeability of OSHF TFC membranes without sacrificing membrane selectivity. Experimental results showed that GQD loading in the PA layer influenced membrane performance. The membrane with a GQD loading of 5 mg L−1 (TFN5) demonstrated an optimal water flux of 30.9 L m−2 h−1 and a specific reverse solute flux (SRSF) of 0.12 g L−1. To investigate the effect of GQDs on the interfacial polymerization (IP) reaction and membrane performance, molecular dynamics (MD) simulation was employed at the water-hexane and water-PA interfaces. The simulation results showed that GQDs decreased the reaction rate during the IP process by reducing the diffusivities of m-phenylenediamine (MPD) and trimesoyl chloride (TMC). Additionally, GQDs reduced water permeability by acting as barriers to water molecules when present at a high concentration near the PA layer surface. At a very high loading, GQDs aggregated at the water-hexane interface and reduced the membrane selectivity by forming non-selective voids at the interface between the PA layer and GQDs. Together with the experimental findings, the MD simulation results delivered a good insight into the GQDs' effect on the TFC membrane's surface and transport properties at both macroscopic and microscopic levels.

High Flux and Antifouling Thin-Film Nanocomposite Forward Osmosis Membrane with Ingrained Silica Nanoparticles

A novel high flux and antifouling thin-film nanocomposite (TFnC) forward osmosis (FO) membrane containing silica (SiO2) nanoparticles was fabricated using a facile electrospinning technique followed by interfacial polymerization on the surface of an electrospun nanofiber mat. Both the electrospun nylon-6 (N6) substrate and the polyamide (PA) active layer contained superhydrophilic SiO2 nanoparticles enhancing the hydrophilicity of the fabricated FO membrane. The electrospun N6/SiO2-supported TFnC FO membrane with a PA/SiO2 composite active layer was robust (tensile strength of 24.1 MPa) with a water contact angle of 14°. The membrane exhibited a high water flux (27.1 LMH) with a low specific reverse salt flux (5.9 × 10–3 mol L–1) at draw solution concentration of 1 M NaCl at 24 °C. The fabricated membrane also showed antifouling propensities for model foulants of sodium alginate and calcium sulfate. After fouling and cleaning operations, the flux recoveries were 98% and 94% (of the initial water flux) for the membranes fouled with sodium alginate and calcium sulfate, respectively. Moreover, a strong interaction between the active layer and the substrate highlighted the structural stability of the fabricated TFnC membrane.

Sewage concentration via a graphene oxide modified thin-film nanocomposite forward osmosis membrane: Enhanced performance and mitigated fouling

• The GO modified TFN-FO membrane shows improved filtration performance. • The GO modified TFN-FO membrane shows an enhanced antifouling property. • The GO modified FO membrane has high and stable sewage concentration performance. • High water flux recovery rates can be achieved by simple membrane cleaning. Upstream intensification of wastewater pre-treatment could improve the efficiency of the biological wastewater treatment process by separating and concentrating the organic matter. Forward osmosis (FO) technology is a potential upstream intensification strategy for sewage concentration. Herein, a high-performance graphene oxide (GO) modified TFN-FO membrane was fabricated and evaluated. The GO modified TFN-FO membrane showed 41% enhancement in water flux without weakening the selectivity property, due to the improved membrane hydrophilicity, thinner polyamide layer and facilitated water transportation by GO. The enhanced filtration performance and antifouling property of the TFN-FO membrane were confirmed by using simulative foulant solution and raw sewage as feed solutions. Moreover, a 41 h semi-continuous filtration experiment was conducted for sewage concentration using real raw sewage as the feed solution. Results indicated that the TFN-FO membrane achieved 4.6 times sewage concentration with high rejection of ammonia, nitrogen and organics. In addition, with a simple in-line water cleaning-in-place (CIP) process, most of the pollutants could be washed off from the surface of the TFN-FO membrane in 15 min and ~ 90% water flux could be recovered after each cleaning cycle. This work demonstrates the potential application of TFN-FO membranes for sewage wastewater concentration.

Triple-layered thin film nanocomposite membrane toward enhanced forward osmosis performance

Forward osmosis (FO) has attracted enormous research interests as a prospective low-energy membrane-separation technology in many potential applications such as desalination, wastewater treatment and agricultural irrigation. The novel thin film nanocomposite (TFN) FO membranes have demonstrated great improvement in separation performance and antifouling capacities. As an intermediate layer, carbon nanotubes (CNTs) could control the interfacial polymerization (IP) process to obtain an ultrathin and dense polyamide (PA) selective layer. Silver phosphate loaded acidified graphitic carbon nitride (aCN/AP) exhibited excellent nanofiller properties, including excellent aqueous dispersity, confined mass transfer, and outstanding bacteriostasis. In view of this, we fabricated TFN FO membranes with CNT as interlayer and aCN/AP as nanofillers into PA layer. Improved hydrophilic and enhanced negatively surface charges were obtained with the incorporation of aCN/AP. The optimal TFN-aCN/AP membrane possessed a higher water flux of 67.0 L m−2 h−1 accompanied with a reverse salt flux lower than 3.0 g m−2 h−1 by using 1 M NaCl as draw solution. Besides, the TFN-aCN/AP membrane showed excellent antibacterial property against both gram-negative E.coli and gram-positive S.aureus with a sterilization rate of 99.0% and 92.0%, respectively. This work provides a new strategy to fabricate novel TFN FO membranes with high permselectivity and excellent antibacterial capacities.

Employing the synergistic effect between aquaporin nanostructures and graphene oxide for enhanced separation performance of thin-film nanocomposite forward osmosis membranes

In this study, novel thin-film nanocomposite (TFN) membranes were developed by incorporating graphene oxide (GO) and Aquaporin Z (AqpZ) reconstituting nanostructure (AQN) into the polyamide (PA) active layer to improve the forward osmosis (FO) performances of the PA TFN membranes. First, the AQN loading in the PA layer was optimized, followed by the GO addition in PA layer at various loadings until the optimal FO process performance was attained. Experimental results showed that GO flakes increased membrane water flux but decreased selectivity by creating non-selective voids in PA layer. Whereas, AQN increased membrane selectivity by healing the non-selective PA defects created by the GO flakes. The synergistic effect of GO-AQN improved the water flux without deteriorating the selectivity of the membrane. The TFN membrane with 0.2 wt% AQN and 0.005 wt% GO loading (TFN50) showed almost 3 folds increase in water flux (24.1 L·m−2·h−1) in comparison to the TFC membrane (8.2 L·m−2·h−1), while retaining the membrane selectivity (0.37 g.L−1). Interestingly, the TFN50 membrane demonstrated a 27% lower specific reverse salt flux (SRSF) and a marginal increase in water flux than the TFN membrane embedded with 0.005 wt% GO and no AQN (TFNGO50). The overall experimental results confirmed that the addition of AQN into GO-based PA TFN membranes could improve the membrane selectivity by reducing the non-selective PA defects created by GO flakes. The results of this study could provide strategies to further enhance the selectivity of GO-based TFN membranes by preventing the formation of defective PA layer.

High performance thin-film nanocomposite forward osmosis membrane based on PVDF/bentonite nanofiber support

In this study, PVDF electrospun nanofibers impregnated with bentonite nanoclay based highly hydrophilic thin-film nanocomposite (TFN) membranes were synthesized by interfacial polymerization of a polyamide selective layer for forward osmosis (FO) applications. It was revealed that the bentonite nanoclay can tune the properties of the PVDF nanofiber supported TFN membranes, including the key parameters, such as hydrophilicity, the β-phase fraction (polar phase), and its mechanical properties. The PVDF/bentonite nanoclay mixture resulted in a significant improvement in FO performance. X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray (EDX) analysis confirmed the successful integration of bentonite nanoclay into the electrospun nanofiber. The prepared TFN membranes showed higher hydrophilicity, mechanical strength and water permeability compared to the pristine PVDF electrospun nanofiber TFN membrane due to an increase in the β-phase fraction (hydrophilicity) by the synergetic effect of electrospinning and addition of bentonite nanoclay. A TFN membrane with the highest nanoclay content (2.0wt%) showed an exceptionally high FO water flux of 40.64L/m2 h at 1M NaCl draw solution, without a considerable increase in reverse solute flux (RSF).

Preparation of a thin-film nanocomposite forward osmosis membrane for the removal of organic micro-pollutants from aqueous solutions

ABSTRACT In this study, a thin-film nanocomposite forward osmosis (TFN FO) membrane was synthesized. The properties and structures of membranes were evaluated for the removal of three organic micro-pollutants from synthetic and real industrial wastewater samples. Laboratory scale fabrication thin-film nanocomposite forward osmosis (FO) membranes composed of a support layer and an active layer. The former was constructed by adding different weight ratios of polyethylene glycol 400 (PEG-400) (0–8 wt.%), polysulfone (PSf), and 1-methyl, 2-pyrrolidone via the phase inversion process, while the latter was synthesized by the incorporation of different weight ratios of graphene oxide (GO) (0–0.012 wt.%), M-phenylenediamine, and 1, 3, 5-benzene trichloride into polyamide layer through the interfacial polymerization reaction. In comparison with thin-film composite (TFC) membranes, the TFN membranes revealed higher hydrophilicity, porosity, water permeability, water flux and salt rejection and lower internal concentration polarization (ICP), reverse salt flux and specific reverse salt flux. The TFN membrane containing 0.008% GO in the active layer and 4% PEG 400 in the support layer exhibited maximum water flux (34.3 LMH) and rejection rate of benzene, phenol and toluene (97%, 84%, and 91%, respectively). The results revealed that the TFN-FO membranes possess a promising potential to improve the water flux and wastewater treatment.

A novel synthetic thin-film nanocomposite forward osmosis membrane modified by graphene oxide and polyethylene glycol for heavy metals removal from aqueous solutions

This study presents the synthesis of a novel thin-film nanocomposite forward osmosis (TFN-FO) membrane and its structural properties and performance; heavy metals removal behavior was further assessed in synthetic and industrial wastewater samples. The novel lab-fabricated TFN-FO membranes included a support layer (SL) constructed by the incorporation of different concentrations (0–8 wt%) of polyethylene glycol 400, polysulfone, and 1-methyl, 2-pyrrolidone via the phase inversion process and an active layer (AL) formed through incorporating different weight ratios (0–0.012 wt%) of graphene oxide (GO), 1, 3-Phenylenediamine and 1, 3, 5-benzene trichloride into the polyamide layer via the interfacial polymerization reaction. Compared with traditional TFC membranes, the TFN-FO membranes exhibited higher hydrophilicity, porosity, water permeability, water flux and salt rejection and lower reverse salt flux, specific reverse salt flux and internal concentration polarization (ICP). The water flux in the TFN membrane (34.3 LMH) increased by 174% and 129%, compared to the TFC membrane (12.5 LMH) and commercial FO membrane (15 LMH), respectively. The rejection rates of TFN FO membranes regarding Pb, Cd, and Cr were 99.9, 99.7 and 98.3%, respectively. The breakthrough time of heavy metals exceeded 14.5 h and 96% concerning flux recovery ratio. The modified FO membranes revealed excellent improvement in membrane structure, FO performances and separation properties.