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.

scholarly journals Polymer Having Dicationic Structure in Dumbbell Shape for Forward Osmosis Process

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 571 ◽  
Author(s):  
Taehyung Kim ◽  
Changha Ju ◽  
Chanhyuk Park ◽  
Hyo Kang
Keyword(s):  
Aqueous Solutions ◽  
Pure Water ◽  
Water Flux ◽  
Forward Osmosis ◽  
Feed Solution ◽  
Solution Temperature ◽  
Solute Flux ◽  
Responsive Polymers ◽  
Draw Solution ◽  
Efficient Recovery

The thermal-responsive polymers, poly(alkane-1,#-diylbis(tri-n-butylphosphonium) 4-vinylbenzenesulfonate) (PSSBP#, # = 8, 6, and 4), where # is the number of carbon atoms in the central bridge structure of the dicationic phosphonium moiety, were synthesized to examine their potential application as draw solutes in forward osmosis (FO). The polymers exhibited low critical solution temperature (LCST) characteristics in aqueous solutions, which is essential for recovering a draw solute from pure water. The LCSTs of the 20 wt% aqueous solutions of PSSBP8, PSSBP6, and PSSBP4 were confirmed to be approximately 30, 38, and 26 °C, respectively, which is advantageous in terms of energy requirements for the recovering draw solute. When the concentration of the PSSBP4 draw solution was 20 wt%, water flux and reverse solute flux were approximately 1.61 LMH and 0.91 gMH, respectively, in the active layer facing the draw solution (AL-DS) system when the feed solution was distilled water. The PSSBP# thermal-responsive draw solute has considerable potential for use as a next-generation draw solute because of its excellent osmotic performance and efficient recovery. Therefore, this study provides inspiration for novel ideas regarding structural transformations of polymers and their applicability as draw solutes.

scholarly journals Superparamagnetic Fe3O4@CA Nanoparticles and Their Potential as Draw Solution Agents in Forward Osmosis

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2965
Author(s):  
Irena Petrinic ◽  
Janja Stergar ◽  
Hermina Bukšek ◽  
Miha Drofenik ◽  
Sašo Gyergyek ◽  
...  
Keyword(s):  
Osmotic Pressure ◽  
Magnetic Measurements ◽  
Water Flux ◽  
Forward Osmosis ◽  
Cross Flow ◽  
Solute Flux ◽  
Colloidal Solutions ◽  
Initial Water ◽  
Cross Flow Filtration ◽  
Draw Solution

In this study, citric acid (CA)-coated magnetite Fe3O4 magnetic nanoparticles (Fe3O4@CA MNPs) for use as draw solution (DS) agents in forward osmosis (FO) were synthesized by co-precipitation and characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic light scattering (DLS), transmission electron microscopy (TEM) and magnetic measurements. Prepared 3.7% w/w colloidal solutions of Fe3O4@CA MNPs exhibited an osmotic pressure of 18.7 bar after purification without aggregation and a sufficient magnetization of 44 emu/g to allow DS regeneration by an external magnetic field. Fe3O4@CA suspensions were used as DS in FO cross-flow filtration with deionized (DI) water as FS and with the active layer of the FO membrane facing the FS and NaCl as a reference DS. The same transmembrane bulk osmotic pressure resulted in different water fluxes for NaCl and MNPs, respectively. Thus the initial water flux with Fe3O4@CA was 9.2 LMH whereas for 0.45 M NaCl as DS it was 14.1 LMH. The reverse solute flux was 0.08 GMH for Fe3O4@CA and 2.5 GMH for NaCl. These differences are ascribed to a more pronounced internal dilutive concentration polarization with Fe3O4@CA as DS compared to NaCl as DS. This research demonstrated that the proposed Fe3O4@CA can be used as a potential low reverse solute flux DS for FO processes.

THE FEASIBILITY OF KAOLIN AS MAIN MATERIAL FOR LOW COST POROUS CERAMIC HOLLOW FIBRE MEMBRANE PREPARED USING COMBINED PHASE INVERSION AND SINTERING TECHNIQUE

2017 ◽  
Vol 79 (1-2) ◽  
Author(s):  
Siti Khadijah Hubadillah ◽  
Mohd Hafiz Dzarfan Othman ◽  
A. F. Ismail ◽  
Mukhlis A. Rahman ◽  
Juhana Jaafar
Keyword(s):  
Phase Inversion ◽  
Low Cost ◽  
Pure Water ◽  
Porous Ceramic ◽  
Water Flux ◽  
Hollow Fibre ◽  
Hollow Fibre Membrane ◽  
Fibre Membrane ◽  
Pure Water Flux ◽  
And Performance

Ceramic hollow fibre membrane (CHFM) demonstrated superior characteristics and performance in any separation application. The only problem associated with this kind of technology is the high cost. In order to effectively fabricate and produce low cost porous CHFM, a series of CHFMs made of kaolin were fabricated via combined phase inversion and sintering technique. The CHFMs from kaolin named as kaolin hollow fibre membranes (KHFMs) were studied at different kaolin contents of 35 wt.%, 37.5 wt.% and 40 wt.% sintered at 1200ºC. The result indicated that by varying kaolin contents, different morphologies were obtained due to changes in the viscosity of ceramic suspension containing kaolin. The optimum kaolin content for KHFM was identified. It was found that KHFM prepared at 37.5 wt% has a mechanical strength and pure water flux of A and B respectively.  

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.

Fabrication and Properties of Alumina Flat Sheet Membrane Surports

2014 ◽  
Vol 955-959 ◽  
pp. 601-604
Author(s):  
De Xiang Liao ◽  
An Chao Geng ◽  
Peng Hao Su ◽  
Dao Lun Feng ◽  
Lin Lin Wang
Keyword(s):  
Sintering Temperature ◽  
Porous Alumina ◽  
Pure Water ◽  
Porous Ceramic ◽  
Water Flux ◽  
Carbon Powder ◽  
Pore Former ◽  
Alumina Support ◽  
Ceramic Support ◽  
Flat Sheet Membrane

The porous ceramic support was realized at various temperature range from 1200°C~1300°C using α-Al2O3 as main material, carbon powder as pore-former, kaolin clay and titanium dioxide as sintering aids and polyvinyl alcohol (PVA) as adhesives. The microstructures of sintered body were significantly affected by the amount of pore-former and sintering temperature. The results indicated that the porosity dramatically increased and the pore radius increased from 2.9 μm to 3.2 μm as carbon powder addition increased from 3 wt.% to 12 wt.%. Correspondingly, their pure water flux depending on the pore structure parameters of the support increased from 1.37 to 4.53 m3.m-2.h-1.bar-1. To prepare porous alumina support with 40% open porosity, carbon powder up to 10 wt.% is appropriate. Sintering experiments showed that the optimum sintering conditions are the sintering temperature of 1300 °C and 2 h holding time at this temperature.

scholarly journals Effect of Kenaf MCC composition on Thin Film Composite membrane for NaCI Rejection

2019 ◽  
Vol 258 ◽  
pp. 04003
Author(s):  
Azman Ismail ◽  
Ramlah Mohd Tajuddin ◽  
Hamizah Mohktar ◽  
Ahmad Fauzi Ismail
Keyword(s):  
Thin Film ◽  
Interfacial Polymerization ◽  
Pure Water ◽  
Water Flux ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Sem Images ◽  
Water Contact ◽  
Membrane Performance ◽  
Pure Water Flux

A modified thin film PSf-MCC reverse osmosis membrane was prepared by interfacial polymerization between aqueous MPD and TMC as the organic monomer. Aim of this study is to determine the effect of MCC in membrane formulation and fabrication. The surface and cross section morphology of TFC PSF/MCC membrane shows MCC particle which able to improve hydrophilicity of the membrane. The SEM images showed dense and porous structure of the MCC incorporated membranes. In addition, the water contact angle measurement also confirmed the increased hydrophilicity of the modified membranes. The effect of MCC on membrane matric influence the membrane performance in terms of NaCl rejection and pure water flux. Results showed that TFC PSf/MCC membrane shows NaCl rejection up to 98.9% compared with TFC PSf membrane. TFC PSf/MCC membrane also showed the highest pure water flux which is 3.712 Lm2/hr compare with TFC PSF membrane which is 3.606 Lm2/hr. The overall result proved that MCC particle could improve membrane hydrophilicity hence, increased pure water flux and salt rejection.

scholarly journals Development of permeability properties of polyamide thin film composite nanofiltration membrane by using the dimethyl sulfoxide additive

2014 ◽  
Vol 4 (3) ◽  
pp. 174-181 ◽  
Author(s):  
Ahmad Akbari ◽  
Sayed Majid Mojallali Rostami
Keyword(s):  
Thin Film ◽  
Dimethyl Sulfoxide ◽  
Aqueous Phase ◽  
High Performance ◽  
Interfacial Polymerization ◽  
Pure Water ◽  
Water Flux ◽  
Film Composite ◽  
Chemical Structures ◽  
Thin Film Composite

A novel polyamide thin film composite (PATFC) as a nanofiltration (NF) membrane was prepared by a modified interfacial polymerization (IP) reaction. Herein trimesoyl chloride and piperazine as the reagents, dimethyl sulfoxide (DMSO) as additive and polysulfone (PSF) ultrafiltration membrane as support were used respectively. The main goal of the present study is to improve TFC membrane water flux by addition of DMSO into the aqueous phase of IP reaction, without considerable rejection loss. Morphological, roughness, and chemical structures of the PATFC membrane were analyzed by scanning electron microscopy, atomic force microscopy (AFM), and Fourier transform infrared spectroscopy (FT-IR), respectively. The AFM analysis demonstrated that as DMSO was added to the aqueous phase, the surface roughness of PATFC membrane increased. Results showed that the pure water flux of modified-PATFC membranes increased up to 46%, compared to nonmodified-PATFC membrane, while salt rejection was not sacrificed considerably. The results elucidated that the addition of DMSO leads to an increase in the number of cross-linking bonds between monomers and pore diameter, which results in enhancement of the membrane flux. Finally, the results showed that the newly developed PATFC membrane is a high-performance NF membrane which augments the efficiency of conventional PATFC membrane.

Composite Membrane with a Calixarene-Containing Polyamide Functional Layer

2018 ◽  
Vol 71 (5) ◽  
pp. 360 ◽  
Author(s):  
Shun Ren ◽  
Dong-Qing Liu ◽  
Rui-Xiang Miao ◽  
Ze-Xian Zhu ◽  
Yu-Feng Zhang
Keyword(s):  
Composite Membrane ◽  
Photoelectron Spectroscopy ◽  
Interfacial Polymerization ◽  
Film Formation ◽  
Pure Water ◽  
Water Flux ◽  
Metal Cations ◽  
Heat Treating ◽  
Skin Layer ◽  
Functional Layer

Monolayer thin films were prepared at the interface of hexane and water to investigate the film formation ability of monomers through interfacial polymerization (IP). A tetra-calix[4]arene chloride derivative (CC) and a diamino-terminated PEG-1000 (DAP) produced a high strength membrane among the tested monomers. IP is consequently proposed to prepare a composite membrane with CC and DAP on a polysulfone (PSF) bulk membrane used for ultrafiltration. The top layer was cross-linked by heat-treating at 60°C for 2 min, with DAP (2 wt.-%) in water and CC (0.05 wt.-%) in hexane. Attenuated total reflectance (ATR)-FTIR and X-ray photoelectron spectroscopy data confirmed that a polyamide was formed on the surface of the PSF substrate. The skin layer was a 3 μm thick smooth thin-film as determined by field emission scanning electron microscopy (FE-SEM), and was also compact without gaps. Pure water flux was ~80.5 L m−2 h−1 under 0.5 MPa. Rejection of MgSO4 was round 22 %, since the calixarene-containing network was a sparse grid, and also had an affinity for metal cations. Although the skin of the composite membrane was compact under SEM, it was easy for metal cations to transfer through. This composite membrane might have good performance in other separation areas as a result of the special structure imparted by using the calixarenes as cross-linking knots.

IMPACTS OF HYDROPHILIC NANOFILLERS ON SEPARATION PERFORMANCE OF THIN FILM NANOCOMPOSITE REVERSE OSMOSIS MEMBRANE

2016 ◽  
Vol 78 (12) ◽  
Author(s):  
C. Y. Chong ◽  
G. S. Lai ◽  
W. J. Lau ◽  
N. Yusof ◽  
P. S. Goh ◽  
...  
Keyword(s):  
Thin Film ◽  
Water Permeability ◽  
Interfacial Polymerization ◽  
Pure Water ◽  
Water Flux ◽  
Water Desalination ◽  
Separation Performance ◽  
Salt Rejection ◽  
Tfc Membrane ◽  
Thin Film Nanocomposite

The membrane technology is still considered a costly method to produce potable water. In view of this, RO membrane with enhanced water permeability without trade-off in salt rejection is desirable as it could further reduce the cost for water desalination. In this study, thin film nanocomposite (TFN) membranes containing 0.05 or 0.10 w/v% hydrophilic nanofillers in polyamide layer were synthesized via interfacial polymerization of piperazine and trimesoyl chloride monomers. The resultant TFN membranes were characterized and compared with a control thin film composite (TFC) membrane. Results from the filtration experiments showed that TFN membranes exhibited higher water permeability, salt rejection and fouling resistance compared to that of the TFC membrane. Excessive amount of nanofillers incorporated in the membrane PA layer however negatively affected the cross-linking in the polymer matrix, thus deteriorating the membrane salt rejection. TFN membrane containing 0.05 w/v% of nanofillers showed better performances than the TFC membrane, recording a pure water flux of 11.2 L/m2∙h, and salt rejection of 95.4%, 97.3% and 97.5% against NaCl, Na2SO4 and MgSO4, respectively. 

scholarly journals The Need for Accurate Osmotic Pressure and Mass Transfer Resistances in Modeling Osmotically Driven Membrane Processes

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 128
Author(s):  
Endre Nagy ◽  
Imre Hegedüs ◽  
Danyal Rehman ◽  
Quantum J. Wei ◽  
Yvana D. Ahdab ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Osmotic Pressure ◽  
Water Flux ◽  
Operating Conditions ◽  
Structural Parameter ◽  
External Mass Transfer ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
The Real ◽  
Parameter Values

The widely used van ’t Hoff linear relation for predicting the osmotic pressure of NaCl solutions may result in errors in the evaluation of key system parameters, which depend on osmotic pressure, in pressure-retarded osmosis and forward osmosis. In this paper, the linear van ’t Hoff approach is compared to the solutions using OLI Stream Analyzer, which gives the real osmotic pressure values. Various dilutions of NaCl solutions, including the lower solute concentrations typical of river water, are considered. Our results indicate that the disparity in the predicted osmotic pressure of the two considered methods can reach 30%, depending on the solute concentration, while that in the predicted power density can exceed over 50%. New experimental results are obtained for NanoH2O and Porifera membranes, and theoretical equations are also developed. Results show that discrepancies arise when using the van ’t Hoff equation, compared to the OLI method. At higher NaCl concentrations (C > 1.5 M), the deviation between the linear approach and the real values increases gradually, likely indicative of a larger error in van ’t Hoff predictions. The difference in structural parameter values predicted by the two evaluation methods is also significant; it can exceed the typical 50–70% range, depending on the operating conditions. We find that the external mass transfer coefficients should be considered in the evaluation of the structural parameter in order to avoid overestimating its value. Consequently, measured water flux and predicted structural parameter values from our own and literature measurements are recalculated with the OLI software to account for external mass transfer coefficients.

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