Download or read book Performance Tuning of Ultrafiltration and Reverse Osmosis Membranes Surface Nano structured with Tethered Poly acrylic Acid Chains written by Yian Chen and published by . This book was released on 2022 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface tethering of hydrophilic polymer brush layers is a popular approach for membrane surface modification with the target of overcoming and mitigating various challenges such as perm-selectivity tradeoff, removal of specific contaminants, and membrane fouling and mineral scaling. In the present study, a systematic investigation of membrane surface structuring with tethered polyacrylic acid (PAA) layers was conducted to tune both reverse osmosis (RO) and ultrafiltration (UF) membranes performance in terms of water permeability, solute rejection, molecular weight cutoff (MWCO), fouling resistance, scaling propensity and cleaning efficacy. Surface nano-structured (SNS) PAA brush layers were synthesized onto the base polysulfone (PSf) UF and polyamide (PA) thin-film composite (TFC) RO membranes via membrane surface activation with different atmospheric pressure plasma (APP) types (i.e., Air, He/O2, and He), followed by graft polymerization (GP) of acrylic acid (AA). Effective tuning of SNS-PAA-PSf UF membrane performance in terms of hydraulic permeability and molecular weight cutoff (MWCO) was feasible by adjustments of the APP and graft polymerization conditions. It was shown, for the first time, that SNS-PAA-PSf membranes can be synthesized with a range of hydraulic permeability (spanning a factor of 1.1-2.6 in magnitude) for a given MWCO, or a range of MWCO (spanning a factor of 1.5-2.3 in magnitude) for a given hydraulic permeability, thereby overcoming the hydraulic permeability-MWCO tradeoff. The SNS-PAA-PSf membrane characteristics (surface hydrophilicity, intrinsic membrane resistance, and PEG MWCO) were responsive to pH and ionic strength due to the conformational change (i.e., swelling/collapse) of the surface tethered PAA chains. Within the tested range of pH (3-11) and ionic strength (0-547 mM), the SNS-PAA-PSf membrane demonstrated self-regulated membrane performance (i.e., Rm 0.74 - 2.29 1013 m-1, and MWCO 1.8 - 15.0 kDa) and surface hydrophilicity (i.e., surface energy -114.5 to -139.2 mJ/m2). UF fouling stress tests with bovine serum album (BSA) and alginic acid in high salinity water and post-cleaning with D.I. water demonstrated reduced flux decline (by ~11.3%) and improved permeability recovery (by ~34%) for the SNS-PAA-PSf membrane relative to the native PSf membrane. The surface tethered PAA chains also improved polyamide (PA) RO membrane removal of nitrate, boron, As (III), and As (V), with rejection of 98.0%, 90.7%, 96%, and 99.6%, respectively, relative to 76.8-84.9%, 87.3-92.1%, and 94.5-97.2% for the tested commercial RO membranes. The increased membrane removal of the specific contaminants is attributed to the surface tethered PAA layer sealing of microscopic defects in the polyamide membrane active layer. The SNS-PAA-PA membrane also exhibited lower flux decline for both gypsum and calcium carbonate scaling tests compared to the tested commercial RO membranes and 100% and 94% permeability recovery post D.I. water flushing, respectively. Scale up of the membrane surface nano-structuring approach, atmospheric pressure plasma-induced graft polymerization (APPIGP), was developed for SNS-PAA-PA membrane sheets of size sufficient for fabrication of 2.5 inch 21 inch spiral-wound RO elements. Laboratory testing of 18 membrane coupons (~2" x 4") extracted from different locations of the SNS-PAA-PA membrane sheet, in terms of water and salt permeability coefficients and intrinsic membrane rejection, demonstrated the similar or higher performance uniformity level compared to Base-PA. SNS-PAA-PA spiral wound elements, fabricated with the above SNS-PAA-PA membrane sheets, outperformed the commercial Dow SW30 element exhibiting lower flux decline and 100% permeability recovery in fouling tests of both BSA and sodium alginate model foulant solutions. Results of the present study suggest that the APPIGP approach can be scaled up to fabricate commercial scale spiral-wound RO elements of superior antifouling properties

Download or read book Reverse Osmosis and Ultrafiltration Membrane Surface Nano Structuring with Tethered Hydrophilic Polymer Layers for Seawater Desalination written by Soomin Kim and published by . This book was released on 2020 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: A systematic investigation of membrane surface nano-structuring (SNS) with surface tethered hydrophilic polymer layers was conducted in order to mitigate fouling of reverse osmosis (RO) and ultrafiltration (UF) membranes and tune membrane performance in seawater desalination. Surface tethered hydrophilic polymer (i.e., polyacrylic acid (PAA)) layers were synthesized onto base polysulfone (PSf) UF and polyamide (PA) thin film composite (TFC) RO membranes via membrane surface activation with an atmospheric pressure plasma (APP), followed by graft polymerization (GP) of acrylic acid. Both APP surface activation and GP conditions impacted the structure of the synthesized tethered PAA layers and RO membrane desalination performance. Detailed characterization of tethered PAA chain extension length via atomic force microscopy (AFM) based force spectroscopy (FS) revealed that the number average molecular weight of the synthesized tethered PAA chains was estimated to be in the range of 13,000-35,000 with chain-chain separation of 1.5-2.4 nm. Extension of the tethered PAA chains in DI water was significantly greater in DI water than in high salinity aqueous environment. UF fouling stress tests with alginic acid in high salinity water and post-cleaning with non-saline water demonstrated permeability restoration of up to 90-100% for a surface nano-structured (SNS)-PAA-PSf membrane relative to 50-70% for the native PSf membrane. Synthesized SNS-PAA-PA BWRO and SWRO membranes having water and salt permeability coefficient in the range of 2.3 - 3.4 L m-2 h-1 bar-1 and 0.15 - 0.54 L m-2 h-1 revealed that membrane surface structuring with a tethered PAA layer enabled tuning membrane performance (in terms of Lp and B) to achieve water/salt selectivity (evaluated as Lp:B ratio) that was significantly higher (by up to 56%) relative to the base PA membranes. It was demonstrated that, depending on APP surface activation and GP conditions, PA TFC membranes could be tuned to have essentially the same salt rejection over a wide permeability range or a given permeability over a range of salt rejection. It was also shown that membrane performance could be achieved that overcomes the permeability-selectivity trade-off. Lastly, the present study developed an approach to scale up the APP surface activation and GP process by performing membrane surface nano-structuring for large PA TFC flat sheet membranes that are suitable for fabricating 2.5" x 21" spiral wound RO elements.

Download or read book Surface Nanostructured Reverse Osmosis Membranes written by Kari J. Moses and published by . This book was released on 2016 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface wettability (or surface hydrophilicity) is of considerable importance in a variety of applications, including membrane separations, lubrication, fibers (e.g., textiles), and biomedical applications. Alteration of surface wettability to the desired level can be of significant benefit in the above applications. Accordingly, the present study focused on a systematic investigation of the modification of surface hydrophilicity via the synthesis of hydrophilic surface tethered polymers. This approach to surface nanostructuring (SNS) was achieved by a two-step process, whereby surface activation is achieved using atmospheric pressure plasma (APP) followed by graft polymerization with a suitable vinyl monomer. The resulting polymer layer consists of chains that are terminally and covalently attached to the underlying surface, being polyamide in the present study. Polyamide (PA) was the selected substrate given the importance of this polymer in various applications (e.g., reverse osmosis (RO) membranes, clothing, body armor, etc.). The degree of surface hydrophilicity imparted to the PA surface was evaluated with respect to the conditions of APP surface activation (i.e., hydrogen, oxygen, and helium as plasma source gases, and exposure time) and graft polymerization (i.e., reaction time, 2-hydroxyethyl methacrylate, acrylamide, acrylic acid, n-vinylpyrrolidone, methacrylic acid, and vinylsulfonic acid monomers, and initial monomer concentration). Helium APP was found to be most effective for the synthesis of tethered polymers on the PA surface leading to an increase in hydrophilicity as quantified by a 15 - 51% reduction in the free energy of hydration ( Giw) of the underlying PA substrate. In particular, polymer-water affinity of the nanostructured PA surfaces, as quantified by the polar component of the surface energy, was a factor of 2.2 - 6.5 higher than for the native PA surface. Overall, surface hydrophilicity increased with increasing tethered polymer layer surface roughness, volume, and thickness; the above trend is consistent with the expected corresponding increased water sorption capacity by the grafted water soluble polymers. The hydrophilic polymer brush layer effectiveness in reducing biofouling propensity and improving surface cleaning post-biofouling (i.e., decreasing surface-solute affinity) was demonstrated for SNS-PA thin-film composite (TFC) RO membranes. SNS-PA RO membranes with polyacrylamide (PAAm), poly(acrylic acid) (PAA), poly(methacrylic acid) (PMAA), and poly(vinylsulfonic acid) (PVSA) brush layers were synthesized, yielding permeability and salt (NaCl) rejection ranges of 4.8 - 6.7 L/m2 h bar and 95.2 - 96.6%, respectively. Performance testing of the SNS-PA-TFC membranes was carried out using secondary wastewater from a municipal wastewater treatment (MWT) plant. Performance tests with the PMAA-SNS-PA and PAAm-SNS-PA membranes (highest and lowest ranking with regard to hydrophilicity, respectively) demonstrated measurable resistance to biofouling. Biofilm layer thickness was up to 4.7 times lower for the above SNS-PA membranes relative to a commercial TFC membrane of similar salt rejection. Moreover, up to 89% of the SNS-PA membrane permeability was recovered after water cleaning, and complete restoration of membrane permeability was attained after chemical (Na2 EDTA) cleaning. In summary, the present approach for tailor-designing surfaces is effective for wettability control through adjustment of the brush layer topography and chemistry which affect the polymer-water affinity. Such hydrophilic tethered polymer surface layers can reduce the biofouling propensity of surfaces, and in particular, increase the biofouling resistance and improve cleaning efficiency of RO membranes.

Download or read book Reverse Osmosis and Ultrafiltration written by S. Sourirajan and published by . This book was released on 1985 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanofiltration written by Muhammad Akhyar Farrukh and published by BoD – Books on Demand. This book was released on 2018-07-11 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: The nanofiltration technique lies between ultrafiltration and reverse osmosis techniques, and it is considered a low-cost process and is capable of removing pesticides, organic matter, desalination of sea water, oil process and pollutants from industrial wastewater. However, the main challenge in implementation of nanofiltration membrane is its ability towards fouling and low performance at high temperature. The use of nanoparticles in the manufacturing of membranes allows for a high degree of control over membrane fouling. Nanoparticle-based membranes can be developed by assembling engineered nanoparticles into porous membranes or blending them with polymeric or inorganic membranes. This book covers topics from multiple ranges from manufacturing of nanofiltration membranes and their applications in wastewater treatment, drinking water treatment, and removal of pollutants, to addressing the fouling issues.

Download or read book Ultrafiltration Membranes and Applications written by Anthony R. Cooper and published by Springer Science & Business Media. This book was released on 2013-03-12 with total page 691 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a record of a symposium, "Ultrafiltration Membranes and Applications," which was held at the l78th National Meeting of the American Chemical Society in Washington, D.C., September 11-13, 1979. In organlzlng these sessions, I hoped to provide a comprehensive survey of the current state of ultrafiltration theory, the most recent advances in membrane technology, and a thorough treatment of existing applications and future directions for ultrafiltration. For me, the symposium was an outstanding success. It was a truly international forum with stimulating presentations and an enthusiastic audience. I hope that some of this spirit has spilled over into this volume, which is intended to reach a much wider audience. I am indebted to the Division of Colloid and Surface Chemistry of the American Chemical Society for their sponsorship. ANTHONY R. COOPER Palo Alto, California }larch, 1980 vii CONTENTS PART I. FUNDMfENTALS Fifteen Years of Ultrafiltration: Problems and Future Promises of an Adolescent Technology . . 1 Alan S. Michaels Production, Specification, and Some Transport Characteristics of Cellulose Acetate Ultrafil tration Membranes for Aqueous Feed Solutions 21 S. Sourirajan, Takeshi Matsuura Fu-Hung Hsieh and Gary R. Gildert Chemical and Morphological Effects of Solute Diffusion Through Block Copolymer Membranes 45 Yatin B. Thakore, Dien-Feng Shieh and Donald J. Lyman Practical Aspects in the Development of a Polymer Matrix for Ultrafiltration. 57 Israel Cabasso Permeability Parameters of a Novel Polyamide Membrane. ... - ...

Download or read book Current Trends and Future Developments on Bio Membranes written by Angelo Basile and published by Elsevier. This book was released on 2019-09-15 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current Trends and Future Developments on (Bio-) Membranes: Reverse and Forward Osmosis: Principles, Applications, Advances covers the important aspects of RO, FO and their combination in integrated systems, along with their specific and well-established applications. The book offers an overview of recent developments in the field of forward and reverse osmosis and their applications in water desalination, wastewater treatment, power generation and food processing. General principles, membrane module developments, membrane fouling, modeling, simulation and optimization of both technologies are also covered. The book's ultimate goal is to support the scientific community, professionals and enterprises that aspire to develop new applications. - Provides an overview of the advances made in combining reverse osmosis membrane technology and the corresponding forward osmosis - Provides a comprehensive review of advanced research on membrane processes for water desalination, wastewater treatments, etc. - Addresses key issues in process intensification and extraction of energy from renewable sources - Identifies further research needs for the practical implementation of these two membrane technologies

Download or read book Functional Nanostructured Materials and Membranes for Water Treatment written by Mikel Duke and published by John Wiley & Sons. This book was released on 2013-03-14 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: Membranes have emerged over the last 30 years as a viable water treatment technology. Earth's population is growing and the need for alternative ways to generate potable water is rising. The recent advent of nanotechnology opens the door to improving processes in membrane technology, which is a promising step on the way to solving the earth's potable water problem. Current performance is enhanced and new concepts are possible by engineering on the nanoscale. This book presents key areas of nanotechnology such as fouling tolerant and robust membranes, enhanced destruction of pollutants and faster monitoring of water quality. 'Functional Nanostructured Materials and Membranes for Water Treatment' is part of the series on Materials for Sustainable Energy and Development edited by Prof. G.Q. Max Lu. The series covers advances in materials science and innovation for renewable energy, clean use of fossil energy, and greenhouse gas mitigation and associated environmental technologies.

Download or read book Advancement in Polymer Based Membranes for Water Remediation written by Sanjay K. Nayak and published by Elsevier. This book was released on 2022-02-23 with total page 677 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advancements in Polymer-Based Membranes for Water Remediation describes the advanced membrane science and engineering behind the separation processes within the domain of polymer-based membrane systems in water remediation. Emphasis has been put on several aspects, ranging from fundamental concepts to the commercialization of pressure and potential driven membranes, updated with the latest technological progresses, and relevant polymer materials and application potential towards water treatment systems. Also included in this book are advances in polymers for membrane application in reverse osmosis, nanofiltration, ultrafiltration, microfiltration, forward osmosis, and polymeric ion-exchange membranes for electrodialysis and capacitive deionization. With its critical analyzes and opinions from experts around the world, this book will garner considerable interest among actual users, i.e., scientists, engineers, industrialists, entrepreneurs and students. - Evaluates water remediation using pressure driven and potential driven membrane processes - Reviews emerging polymer systems for membranes preparation - Offers a comprehensive analysis in the development of polymer-based membranes and their applications in water remediation - Analyzes membrane performance parameters to evaluate separation efficiency for various water pollutants - Covers concept-to-commercialization aspects of polymer-based membranes in terms of water purification, pollutant removal, stability and scalability

Download or read book Reverse Osmosis Membrane Research written by H. Lonsdale and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: Th i s book had its orl gl n in the sympos i urn on "Polymers for Desalination" sponsored by the Division of Polymer Chemistry of the American Chemical Society and held in September, 1971 in Wash ington D. C. at the 162nd national meeting of the Society. However, the book is not simply the proceedings of that symposium. A num ber of additional papers were contributed by other workers in the field, and the original papers presented at the symposium have, for the most part, been expanded. The book thus represents a broad cross section of membrane research and development activities in the United States and abroad within the field of reverse osmosis. The purposes of the book are to bring attention to important new developments in this field, to suggest what the next generation of reverse osmosis equipment may look like, and to indicate where fur ther research and development are needed. The vast majority of the papers collected here represent work supported by the Office of Saline Water of the United States Department of the Interior, and the emphasis here is clearly on the application of the reverse os mosis process to water purification. However, many of the concepts, methods, and conclusions are expected to be useful in other areas of membrane science and technology.

Download or read book Ultrafiltration and Microfiltration Handbook written by Munir Cheryan and published by CRC Press. This book was released on 1998-01-26 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soon after its publication in 1987, the first edition of Ultrafiltration Handbook became recognized as the leading handbook on ultrafiltration technology. Reviews in professional journals praised it as an authoritative and substantive information resource on this technology. Now a completely, updated and expanded edition is available under the title, Ultrafiltration and Microfiltration Handbook. This practical handbook systematically covers the basics of this technology from its scientific fundamentals to a wide range of industrial applications. The presentation is clear and concise with the emphasis on practical use. Many schematics and micrographs illustrate membranes, equipment and processes. Numerous tables and graphs provide useful data on specifications and performance. The updated information is useful to all those involved in the use of separation and filtration in industrial processes.

Download or read book Ultrafiltration Membrane Cleaning Processes written by Guillem Gilabert-Oriol and published by Walter de Gruyter GmbH & Co KG. This book was released on 2021-06-08 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the ultrafiltration membranes, specifically focusing on the elements that are produced using PVDF technology and out-side-in configuration. It specifically targets ultrafiltration technology as a pretreatment of seawater reverse osmosis desalination process. However, what is described in the book can be leveraged in other ultrafiltration membrane types. It explains how to significantly improve the efficiency of the process.

Download or read book Microfiltration and Ultrafiltration written by Zeman and published by Routledge. This book was released on 2017-11-22 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integrates knowledge on microfiltration and ultrification, membrane chemistry, and characterization methods with the engineering and economic aspects of device performance, device and module design, processes, and applications. The text provides a discussion of membrane fundamentals and an analytical framework for designing and developing new filtrations systems for a broad range of technologically important functions. It offers information on membrane liquid precursors, fractal and stochastic pore space analysis, novel and advanced module designs, and original process design calculations.

Download or read book Ultrathin Membranes for Treating Metal Finishing Effluents by Reverse Osmosis written by North Star Research and Development Institute (Minneapolis, Minn.) and published by . This book was released on 1972 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Use of Improved Membranes in Tertiary Treatment by Reverse Osmosis written by McDonnell Douglas Corporation. Astropower Laboratory and published by . This book was released on 1970 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design of Advanced Reverse Osmosis and Nanofiltration Membranes for Water Purification written by Chaoyi Ba and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Most commercially available reverse osmosis (RO) and nanofiltration (NF) membranes are based on the thin film composite (TFC) aromatic polyamide membranes. However, they have several disadvantages including low resistance to fouling, low chemical and thermal stabilities and limited chlorine tolerance. To address these problems, advanced RO/NF membranes are being developed from polyimides for water and wastewater treatments. The following three projects have resulted from my research. (1) Positively charged and solvent resistant NF membranes. The use of solvent resistant membranes to facilitate small molecule separations has been a long standing industry goal of the chemical and pharmaceutical industries. We developed a solvent resistant membrane by chemically cross-linking of polyimide membrane using polyethylenimine. This membrane showed excellent stability in almost all organic solvents. In addition, this membrane was positively charged due to the amine groups remaining on the surface. As a result, high efficiency (> 95%) and selectivity for multivalent heavy metal removal was achieved. (2) Fouling resistant NF membranes. Antifouling membranes are highly desired for 0́−all0́+ applications because fouling will lead to higher energy demand, increase of cleaning and corresponding down time and reduced life-time of the membrane elements. For fouling prevention, we designed a new membrane system using a coating technique to modify membrane surface properties to avoid adsorption of foulants like humic acid. A layer of water-soluble polymer such as polyvinyl alcohol (PVA), polyacrylic acid (PAA), polyvinyl sulfate (PVS) or sulfonated poly(ether ether ketone) (SPEEK), was adsorbed onto the surface of a positively charged membrane. The resultant membranes have a smooth and almost neutrally charged surface which showed better fouling resistance than both the positively charged NF membranes and commercially available negatively charged NTR-7450 membrane. In addition, these membranes showed high efficiency for removal of multivalent ions (> 95% for both cations and anions). Therefore, these antifouling surfaces can be potentially used for water softening, water desalination and wastewater treatment in a membrane bioreactor (MBR) process. (3) Thermally stable RO membranes. Commercial RO membranes cannot be used at temperature higher than 45°C due to the use of polysulfone substrate, which often limits their applications in industries. We successfully developed polyimides as the membrane substrate for thermally stable RO membranes due to their high thermal resistance. The polyimide-based composite polyamide membranes showed desalination performance comparable to the commercial TFC membrane. However, the key advantage of the polyimide-based membrane is its high thermal stability. As the feed temperature increased from 25oC to 95oC, the water flux increased 5 - 6 times while the salt rejection almost kept constant. This membrane appears to provide a unique solution for hot water desalination and also a feasible way to improve the water productivity by increasing the operating temperature without any drop in salt rejection.

Download or read book High Performance Water Filtration Membranes Using Surface Modification and New Materials written by Xinwei Huang and published by . This book was released on 2016 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water scarcity is one of the most critical challenges faced by mankind and it is only getting worse due to source pollution and rising population. There is critical need for the development of water filtration membranes in order to treat polluted water and turn water from non-potable sources such as waste waster and ocean water into freshwater for human consumption and agricultural irrigation. Filtration Membranes are generally classified into four categories: microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO), with decreasing pore size for rejecting different sized substances. Commercial filtration membranes are able to provide decent flux and rejection for their targeted applications. However, most of them suffer from fouling issues when the microorganisms and organic matter such as proteins and polysaccharides in the water source deposit onto the membrane surface, impeding the permeation of water and lowering the flux. Therefore, it is of high demand to develop membranes that are anti-fouling. Foulants such as protein particles adhere to the membrane surface via hydrophobic interactions. In order to minimize such effects, a typical way is to increase the hydrophilicity of the membrane by surface modification or by utilizing hydrophilic membrane materials. Foulants also tend to get trapped in the open "pores" on a rough membrane surface with ridges and valleys. It is then expected that a smoother membrane surface tend to lessen such effects. Incorporating antimicrobial properties into the membrane is also an effective way to reduce fouling as this inhibits the growth of microorganisms on the membrane surfaces. New materials are also used to fabricate membranes with improved performance. Conducting polymers have recently been discovered as a new category of membrane-making materials that are hydrophilic and low-fouling. A new type of polyaniline derivative has been used to fabricate UF membranes that demonstrate chlorine resistance and anti-fouling properties. Nanostructured polyanilines are highly processable and possess unique properties that can be used in the membrane field as well as many other applications such as sensors, electrochromic devices, supercapacitors and antistatic coatings with enhanced performance, as described in a review section at the end of this thesis.