scholarly journals Enhancing chlorine resistance in polyamide membranes with surface & structure modification strategies

2021 ◽  
Author(s):  
Muhammad Faisal Idrees ◽  
Umar Tariq
Keyword(s):  
Reverse Osmosis ◽  
Exposure Time ◽  
Carbon Nitride ◽  
Water Flux ◽  
Structure Modification ◽  
Salt Rejection ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene ◽  
Ro Membrane ◽  
Graphene Oxide Quantum Dots

Abstract Higher efficient reverse osmosis (RO) membrane development is a significant issue due to the payoff among salt rejection and water flux and permissive chlorine attacking and fouling potential. Weak chlorine resistance is a distinctive challenge for composite polyamide thin-film reverse osmosis membranes. A commercial aromatic membrane was modified by grafting nitrogen-doped graphene oxide quantum dots (N-GOQDs) to enhance chlorine resistance, embedding two-dimensional MXene Ti3C2Tx, introducing synthetically reductive thioether units and oxidized graphitic carbon nitride (OGCN). In this work, salt rejection, chlorine resistance, and water flux increased compared to the pristine membrane. Comprehensive arrangement of desalination performance and chlorine resistance achieved by varying time and concentrations of prepared chemicals. For instance, improved chlorine resistance, after 12 hours of grafting time by N-GOQDs dopped membrane was 32.8%, after 6 hours of exposure time by MXene Ti3C2Tx membrane was 27.4%, after 1 hour of exposure time by thioether membrane was 28.1% and after 40 hours of doping time by OGCN membrane was 31.3%. N-GOQDs dopped membrane showed a good chlorine resistant property, but on the other hand, thioether nano units showed other properties more effectively, including water flux, salt rejection, and less reaction time.

scholarly journals Polyamide/nitrogen-doped graphene oxide quantum dots (N-GOQD) thin film nanocomposite reverse osmosis membranes for high flux desalination

Desalination ◽  
2019 ◽  
Vol 451 ◽  
pp. 125-132 ◽  
Author(s):  
Mahdi Fathizadeh ◽  
Huynh Ngoc Tien ◽  
Konstantin Khivantsev ◽  
Zhuonan Song ◽  
Fanglei Zhou ◽  
...  
Keyword(s):  
Thin Film ◽  
Quantum Dots ◽  
Graphene Oxide ◽  
Reverse Osmosis ◽  
High Flux ◽  
Nitrogen Doped ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene ◽  
Graphene Oxide Quantum Dots ◽  
Thin Film Nanocomposite

scholarly journals Innovative Nanostructured Membranes for Reverse Osmosis Water Desalination

2020 ◽  
Author(s):  
Haleema Saleem ◽  
Syed Javaid Zaidi
Keyword(s):  
Reverse Osmosis ◽  
Separation Efficiency ◽  
Interfacial Polymerization ◽  
Water Flux ◽  
Water Desalination ◽  
Selective Layer ◽  
Salt Rejection ◽  
Membrane Performance ◽  
Tfc Membrane ◽  
Ro Membrane

Reverse osmosis (RO) is considered as the most widely utilized technique worldwide for water treatment. However, the commercial thin-film composite (TFC) membranes, which are normally made of polyamide (PA) through interfacial polymerization (IP), still experience certain major issues in performance and fabrication. The spin assisted layer-by-layer (SA-LbL) technique was established for overcoming some drawbacks with commercially available PA membranes. Also, recent investigations have recognized the nanoparticle inclusion into the selective layer as a powerful technique for improving the membrane efficiency. Hence, two different methodologies are presented here to improve the membrane performance, i.e., (1) SA-LbL technique to fabricate TFC membrane by the deposition of alternate ultrathin layers of different polyelectrolytes on polysulfone (PSF) commercial ultrafiltration membrane and (2) the nanoclay incorporation into the membranes during IP process to develop TFC membrane. Two types of nanoclays, cloisite (CS)-15A and montmorillonite (MNT), were incorporated to enhance the separation efficiency. This SA-LbL is an innovative method for the RO membrane manufacture, and has not been described earlier to the best of our knowledge. In addition, this work validated for the first time, the efficiency of the two nanoclays at the PA selective layer in the RO membrane. The membrane performance was evaluated using sodium chloride solution in a cross-flow permeation-testing cell for salt rejection and water flux. The results show significant improvement in water flux and salt rejection. The permeation test of 120 bilayers of poly (allylaminehydrochloride)/poly (vinylsulfate) on PSF substrate showed water flux of 37 L/ (m2.h) and salt rejection of 53%, for a 2000-ppm salt solution feed. The highest water flux of 40 L/m2.h with 80% salt rejection, relative to the control membrane was obtained for the membranes containing nanoclays at 25oC temperature, 40.0 bar pressure and 2000 ppm feed concentration. Thus, our study demonstrated that these TFC membranes are promising, and these novel fabrication techniques are great tool to manufacture the RO membrane.

Grafted cellulose acetate reverse osmosis membrane using 2-acrylamido-2-methylpropanesulfonic acid for water desalination

2016 ◽  
Vol 16 (4) ◽  
pp. 1046-1056 ◽  
Author(s):  
Ashraf Morsy ◽  
Shaker Ebrahim ◽  
El-Refaie Kenawy ◽  
Tarek Abdel-Fattah ◽  
Sherif Kandil
Keyword(s):  
Cellulose Acetate ◽  
Reverse Osmosis ◽  
Membrane Surface ◽  
Water Flux ◽  
Contact Angles ◽  
Water Desalination ◽  
Salt Rejection ◽  
Morphological Studies ◽  
Phase Inversion Technique ◽  
Ro Membrane

Reverse osmosis (RO) membranes based on cellulose acetate (CA), were prepared using a phase inversion technique. To improve the hydrophilicity, salt rejection and water flux of these membranes, a novel grafting of 2-acrylamido-2-methylpropanesulfonic acid (AMPSA) was added on the top surface of the CA-RO membranes. The grafted CA-RO membranes were characterized by Fourier transform infrared spectroscopy (FTIR), contact angle, and scanning electron microscopy techniques. It was found that the contact angles were 58° and 45° for pristine CA and 15 wt% grafted CA-RO membranes, respectively, which suggest an increase in the membrane surface hydrophilicity after grafting. The morphological studies of the surface of the pristine CA-RO membrane revealed a typical ridge-and-valley morphology and displayed a relatively high surface roughness of 337 nm, and a significant decrease at 15 wt% of grafted CA-RO membrane to 7 nm. The effect of the grafting percentages of AMPSA on the water flux and salt rejection was studied using a cross flow RO unit. The salt rejection and water flux of the grafted CA-RO membrane with 15 wt% were 99.03% and 6 L/m2h, respectively.

scholarly journals Protonated Carbon Nitride Incorporated Polyamide Thin Film Nanocomposite for Reverse Osmosis Desalination

2019 ◽  
Vol 23 (2) ◽  
Author(s):  
A. Abdul Aziz ◽  
P. S. Goh ◽  
M. A. Azali ◽  
M. N. Zainal Abidin ◽  
M. H. Abu Ba'dah
Keyword(s):  
Thin Film ◽  
Reverse Osmosis ◽  
Water Permeability ◽  
Acid Treatment ◽  
Carbon Nitride ◽  
Salt Rejection ◽  
Dead End ◽  
Filtration System ◽  
Ro Membrane ◽  
Thin Film Nanocomposite

Protonated carbon nitride (pCN) prepared from acid treatment of carbon nitride (CN) was incorporated in the polysulfone (PSf) substrate and polyamide (PA) layer to produce thin film nanocomposite (TFN) membrane. The hydrophilicity of CN is expected to improve the surface hydrophilicity of the membrane and acid treatment of nanoparticle is aimed to further enhance the surface structure and prevent the agglomeration of nanomaterial from taking place. pCN loading used in the PSf substrate was 0.5% while in the PA layer was varied as 0.05%, 0.1% and 0.15%. All the membrane prepared were characterized in terms of morphology, structural properties, and surface chemistry. Reverse osmosis dead-end filtration system was used to determine the water permeability and the salt rejection. It was observed that, all the membrane prepared could maintain the salt rejection with improvement of water permeability. However, the salt rejection was sacrificed when higher loading of 0.15% pCN was tested, although the water permeability of the membrane has reached approximately 0.5 LMHbar. This work demonstrates that the use of pCN in RO membrane can improve the water permeability without sacrificing the salt rejection.

scholarly journals High-flux polyamide reverse osmosis membranes by surface grafting 4-(2-hydroxyethyl)morpholine

RSC Advances ◽  
2017 ◽  
Vol 7 (65) ◽  
pp. 40705-40710 ◽  
Author(s):  
Ruizhi Pang ◽  
Kaisong Zhang
Keyword(s):  
Reverse Osmosis ◽  
Water Flux ◽  
Surface Grafting ◽  
High Flux ◽  
Ro Membrane ◽  
Reverse Osmosis Membranes

A surface grafted PA RO membrane with 4-(2-hydroxyethyl)morpholine was fabricated to improve water flux.

scholarly journals Tuning the Surface Structure of Polyamide Membranes Using Porous Carbon Nitride Nanoparticles for High-Performance Seawater Desalination

Membranes ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 163 ◽  
Author(s):  
Zongyao Zhou ◽  
Xiang Li ◽  
Digambar B. Shinde ◽  
Guan Sheng ◽  
Dongwei Lu ◽  
...  
Keyword(s):  
Thin Film ◽  
Porous Carbon ◽  
Carbon Nitride ◽  
Interfacial Polymerization ◽  
Water Flux ◽  
The State ◽  
Seawater Desalination ◽  
Covalent Bonds ◽  
Salt Rejection ◽  
Positive Effects

Enhancing the water flux while maintaining the high salt rejection of existing reverse osmosis membranes remains a considerable challenge. Herein, we report the use of a porous carbon nitride (C3N4) nanoparticle to potentially improve both the water flux and salt rejection of the state-of-the-art polyamide (PA) thin film composite (TFC) membranes. The organic–organic covalent bonds endowed C3N4 with great compatibility with the PA layer, which positively influenced the customization of interfacial polymerization (IP). Benefitting from the positive effects of C3N4, a more hydrophilic, more crumpled thin film nanocomposite (TFN) membrane with a larger surface area, and an increased cross-linking degree of PA layer was achieved. Moreover, the uniform porous structure of the C3N4 embedded in the ”ridge” sections of the PA layer potentially provided additional water channels. All these factors combined provided unprecedented performance for seawater desalination among all the PA-TFC membranes reported thus far. The water permeance of the optimized TFN membrane is 2.1-folds higher than that of the pristine PA-TFC membrane, while the NaCl rejection increased to 99.5% from 98.0%. Our method provided a promising way to improve the performance of the state-of-art PA-TFC membranes in seawater desalination.

Effects of DMSO and glycerol additives on the property of polyamide reverse osmosis membrane

2016 ◽  
Vol 74 (7) ◽  
pp. 1619-1625 ◽  
Author(s):  
Fengjing Wu ◽  
Xiaojuan Liu ◽  
Chaktong Au
Keyword(s):  
Contact Angle ◽  
Reverse Osmosis ◽  
Water Contact Angle ◽  
Interfacial Polymerization ◽  
Water Flux ◽  
Cross Flow ◽  
Interfacial Free Energy ◽  
Polymerization Process ◽  
Water Contact ◽  
Salt Rejection

The polyamide reverse osmosis (RO) membranes were prepared through interfacial polymerization of m-phenylenediamine (MPD) and trimesoyl chloride (TMC). The use of dimethyl sulfoxide (DMSO) and glycerol as additives for the formation of thin-film composite (TFC) was investigated. We studied the effect of DMSO and glycerol addition on membrane property and RO performance. Microscopic morphology was examined by atomic force microscopy and scanning electron microscopy. The surface hydrophilicity was characterized on the basis of water contact angle and surface solid–liquid interfacial free energy (−ΔGSL). Water flux and salt rejection ability of the membranes prepared with or without the additives were evaluated by cross-flow RO tests. The results reveal that the addition of DMSO and glycerol strongly influences the property of the TFC RO membrane. Compared to the MPD/TMC membrane fabricated without DMSO and glycerol, the MPD/TMC/DMSO/glycerol membrane has a rougher surface and is more hydrophilic, showing smaller water contact angle and larger −ΔGSL value. Without decrease in salt rejection ability, the MPD/TMC/DMSO/glycerol membrane shows water flux significantly larger than that of the MPD/TMC membrane. The unique property of the MPD/TMC/DMSO/glycerol membrane is attributed to the cooperative effect of DMSO and glycerol on membrane structure during the interfacial polymerization process.

Sign in / Sign up

Export Citation Format

Share Document