File Name: uf mf membrane water treatment principles and design .zip
- UF/MF Membrane Water Treatment: Principles and UF-MF Book Flyer.pdf · 2 UF/MF Membrane Water...
- Importance and Significance of UF/MF Membrane Systems in Desalination Water Treatment
By Iqbal Ahmed, Khaled S. Balkhair, Muhammad H. Albeiruttye and Amer Ahmed Jamil Shaiban.
UF/MF Membrane Water Treatment: Principles and UF-MF Book Flyer.pdf · 2 UF/MF Membrane Water...
By Iqbal Ahmed, Khaled S. Balkhair, Muhammad H. Albeiruttye and Amer Ahmed Jamil Shaiban. The recent development made in the integration of established desalination processes, such as spiral wound reverse osmosis SWRO , multi-stage flash MSF , multi-effect distillation MED , electrodialysis ED desalination, and UF pretreatment, is addressed. Almost every chemical process involves at least one separation or purification step, and the chemical industry has developed a range of separation techniques to facilitate recovery of the required products.
In recent years, membranes and membrane separation techniques have grown from laboratory tool to an industrial process with considerable technical and commercial impact.
Instantly, the membrane processes are faster, more efficient, and economical than conventional separation techniques, particularly for desalination water treatment. Later on, Dr. Adolf Eugen Fick from Germany has introduced diffusion law and was developed the first high-pressure synthetic membrane made from nitrocellulose in [ 3 ]. After 50 years, Dr. Bechhold from Germany developed first low-pressure cellulosic membranes collodion , which is prepared by impregnating filter paper with glacial acetic acid.
The first such low-pressure membranes were produced in , and Dr. After Dr. But, the little flux was the main drawback of such Bechhold's type membranes. These deficiencies put together are too costly and practically inappropriate.
The period of cost-effective feasible membrane advancement, which was started in the late s and prolongs to this date, may be divided into two time periods.
The first generation was from to of cellulose acetate integral asymmetric membranes, and the second generation started from to of noncellulosic asymmetric membranes [ 10 , 11 ]. After the breakthrough of phase inversion the history of the synthetic membrane were entirely changed which was active properties regarding mechanical strength, membrane morphologies, and ten times higher performance than the earlier membrane.
The beginning of thin-film-composite TFC polymeric membranes started during , initiated by a research institute and one of its first employees, Peter S. Francis [ 11 , 12 ]. A significant discovery was made in the art of thin-film-composite membranes by Cadotte in with the beginning of large-scale commercial polymeric membrane. Cadotte invented two innovative techniques of TFC membrane based on interfacial polymerization and solution coating methods [ 12 ].
During —, the researchers developed important methods of membrane materials synthesis, membrane fabrication process, membrane geometry, separation, and purification processing techniques. Moreover, by the end of 19th century, the advancement of membrane growth has enhanced performance, steadiness, and provided lower operating costs, making membranes the preferred technology in the water treatment industry as well as in the food and pharmaceutical industries [ 1 , 10 , 13 ].
Key historical development of UF membrane from Market laboratory - scale to commercial scale [ 10 , 11 ]. A pressure gradient 0. Combine Eq.
Also the pore size, some other factors such as interactions between UF feed components and membrane matrix play a significant role in the transport through the membrane [ 10 , 17 — 19 ].
Sakai [ 19 ] reported that the Eq. Sakai and co-worker also indicated that Verniory et al. Nakao [ 19 — 22 ] has reported that in the case of known relation between flux and rejection, the membrane structure can be characterized such as thickness, pore size, pore radius, pore volume, pore density, and tortuosity, respectively. When Eq. Unfortunately, it is impossible to determine the pore sizes of asymmetric membranes with the aid of Hagen Poiseuille equation 3 , which makes it necessary to use, for this purpose, the data of more complicated methods [ 23 ].
Among all above methods, the most informative are the means of electron microscopy, gas pycnometer, which give the possibility to determine pore sizes and pore size distributions PSD of asymmetric membranes [ 18 , 24 — 27 ]. Synthetic polymeric membranes can be divided into hydrophobic and hydrophilic classifications, and structure can also be classified.
Structural classification is critical because it is the structure which determines the separation mechanisms and the membrane application [ 10 , 28 , 29 ]. Membranes can be further classified as symmetric or asymmetric [ 10 , 29 ]. The symmetric membranes can be porous, cylindrical porous, and homogeneous nonporous.
The asymmetric membranes can be porous, microporous with top layer, and composite that is consisting of a porous substrate with a dense top layer. The thickness of the top layer in asymmetric membranes is in the range of 0.
The development of pressure-driven membrane technology was began after Loeb-Surirajan and Riley et al. Ability to form polymeric membranes into compact, high-surface-area, economical membrane configuration. Modern membrane technology began in late s, the development of polymeric membrane chemistry and processing techniques are used in membrane fabrication. With the developments in polymeric membrane materials, manufacturing technologies, and water treatment processing systems have made this technology an efficient, economical for water treatments, and competitive with traditional water treatment methods [ 10 , 15 , 29 ].
Each application enforces precise specifications on the membrane material and membrane structure. The revolution in understanding the origin of these structural elements of Loeb and Surirajan phase inversion process was obtained by Wienk et al. Innovative processing of polymers for membranes, particular neatness of membrane industrialized. Groundwork of nanoparticles mixed matrix membranes for the synergistic allying of different functions by different polymeric materials.
Such kind of polymeric membranes may well circumvent many of these limitations. Several researchers and manufacturers have revealed that the natural phenomenon is responsible for restricting the permeate flux during cross-flow i. Throughout the early stage of filtration process within a cross-flow rotation, concentration polarization is one of the prime causes for flux reductions [ 39 , 40 ].
The decrease in the flux for pure water from cycle to cycle, because of fouling, the flux decline within a period due to concentration polarization, and the average flux under steady state level. The latter is also decreasing from cycle to cycle, suggests irreversible solute adsorption or fouling [ 41 — 43 ]. And of the solute retained on a membrane surface leads to increasing permeate flow resistance at the membrane wall region.
Strategies to minimize the effect of fouling can be divided into two groups: avoidance and remediation. The remediation is to clean up by the cleanup process, is usually done by chemical cleaning at regular times [ 44 ], and this is necessary for all membrane processes in nearly all applications.
However, large differences in the cleaning frequency can be found, ranging from daily to yearly, depending on the concentration of foulant and the pretreatment. A large number of cleaning agents are commercially available. The choice of optimal product depends on feed characteristics. Acid cleaning is suitable for the removal of precipitated salts, such as CaCO 3 , whereas alkaline cleaning is used to remove adsorbed organics.
Nearly, all cleaning products contain detergents. A short pulse of water or air from the permeate side to the feed side efficiently removes all fouls blocking the membrane pores [ 45 ]. This principle is often applied in a dead-end or semi-dead-end filtration.
It is possible to avoid fouling by using adequate pretreatments, such as coagulation precipitation, or slow sand filtration [ 10 , 15 , 29 , 46 ]. With the improvements in this technology to make membrane for separation and purifications economically competitive with traditional separation methods [ 10 , 17 , 45 ], the use of these membranes has increased exponentially.
A suitable porous membrane should be excellent in permeability, hydrophilicity, and chemical resistance to the feed streams. An asymmetric membrane is a good option for high permeability. Thus, currently, much effort is being devoted to improve the performance of the existing membranes regarding anti-fouling properties, high mechanical strength, and excellent chemical resistance.
To make a porous or microporous membrane, some mineral or ceramic membranes have been developed. However, polymeric membranes are yet mostly used [ 49 , 50 ]. Nevertheless, since the first membrane cellulosic and noncellulosic materials were described by Reid and Breton in late [ 51 ], numerous materials have been developed to improve the capacity and performance of membranes filtration [ 11 , 17 , 29 ]. For a given treatment stream, a particular polymeric membrane material can be selected from an assortment of candidates.
Till now, there are more than materials cellulosic, noncellulosic polymers, composite, and inorganic that have been used to manufacture membranes [ 11 , 17 ]. The range of materials from which it is possible to create some form of artificial membrane structure is extensive. Each year, number of research papers in polymer and membrane science present many new examples of materials that demonstrate semi-permeable qualities at some scale.
However, only a very limited number of these potential candidates make it to the commercial environment [ 1 , 52 — 54 ]. Very few materials possess the structural and chemical properties necessary to render them suitable for application in industrial scale membrane processes. These materials can be used to make a hydrophobic polymer more hydrophilic.
Commercial available hydrophilic and hydrophobic polymers for membrane production [ 11 , 17 , 29 , 53 ]. Typically, all these thermoplastic base materials can easily be dissolved in aprotic solvents and produce membranes with excellent thermal, hydrolytic, and mechanical stability properties in both hot and wet environments.
To prepare membranes for the liquid separation processes using repeated applications with either hot water or sterilization to keep the membrane clean [ 11 , 17 , 63 ]. Sulfonated polyethersulfone membrane has been customized to be drastically more hydrophilic than standard PES, PSF membranes [ 29 , 42 , 58 — 60 , 62 , 63 ]. It is biocompatible and has highest opposition to fouling by hydrophobic compounds such as fats, lipids, anti-foams, and other similar highly fouling substances [ 1 , 10 , 32 , 42 , 60 , 64 ].
However, surface contamination which may lead to deterioration in membrane performance is also known to be governed by the membrane surface properties and obstacle in membrane performance. Therefore, the membronologist has been paid much attention to the membrane surface modification and were identified theoretical and phenomenological reasons behind the hydrophobic reasons of thermoplastic polymers [ 17 , 29 , 32 , 64 , 65 ].
Also during 50 years, membronologist has developed very innovative methods to modify the hydrophobic membrane surface into hydrophilic. Moreover, many numbers of high cited research manuscripts and books have been published regarding membrane surface modification techniques.
In this book, relevant topics covered in the ACS Symposium summarize recent advances in various research areas for development of novel materials used in membrane separations. Xu and co-authors [ 68 ] published a very comprehensive book on surface engineering of polymer membranes, squeezes those processes which alter membrane surfaces to improve their in-service performance. Also, improve biocompatibility, act as a diffusion barrier, provide bio- or chemical functionalities, mimic a biomembrane, fabricate nanostructures, or directly improve the esthetic appearance of the membrane surface.
Morao et al. Mulder, Pinnau and Freeman said plasma treatment or grafting [ 29 , 66 ] and UV-induced grafting [ 67 ] on a polymeric membrane surface. Several other authors also reported chemical sulfone enrichment [ 60 , 71 ], chemical dehydrofluorination by alkaline solution [ 71 — 73 ], coating temperature-sensitive polymeric brushes [ 74 ], and grafting with pH- and ionic-strength-sensitive polymeric brushes [ 10 , 29 , 72 , 74 ].
Moreover, researchers has been used several other techniques such as, the irradiation-induced grafting [ 75 ], physical adsorption of water-soluble polymers [ 76 ], a formation of Langmuir-Blodgett films [ 77 ], thermal grafting of a hydrophilic polymeric surface coating [ 78 , 79 ], and photografting with UV irradiation [ 68 ], respectively.
All these surface modification techniques are usually applied on hydrophobic-casted surface and these are complicated and expensive and require at least one additional step in the membrane preparation process [ 68 ]. Besides, the physical techniques, all the methods mentioned above allow the membrane surface to be modified without affecting the bulk properties too much when appropriate conditions the modification time are selected.
However treating polymeric membrane surface by physical method resulting unstable and mechanical strength drawback [ 80 — 82 ]. The principle of synthesis is to transform the polymeric material using a convenient method to achieve a polymeric membrane structure with a significant morphology for a distinct separation.
The techniques that are being employed for the preparation of artificial membrane are phase inversion, stretching of films, irradiation and etching of films, track-etching, sintering of powders, sol—gel process, microfabrication vapor deposition, and coating [ 11 , 29 , 33 , 49 , 81 ].
Because of variability in DBPs characteristics, eliminate completely from drinking water by single technique is impossible. Also, we provide an overview of existing and potentially Membrane filtration techniques, highlight their strengths and drawbacks. MF membranes are a suitable alternative to remove suspended solids and colloidal materials. RO can remove both organic and inorganic DBPs and precursors simultaneously. NF can be used to remove compounds from macromolecular size to multivalent ions. In recent years potable water security is considered as a worldwide issue. The need to remove pathogens from drinking water supplies is long recognized.
Importance and Significance of UF/MF Membrane Systems in Desalination Water Treatment
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Membrane bioreactors MBRs have recently become widely accepted as an advanced technology for treatment of domestic and industrial wastewaters. The objective of this review is to provide overview on MBR technology for wastewater treatment application. It includes discussions on the fundamental, core problems membrane fouling , recent effective development approach dynamic filtration systems and future research direction of MBRs.
Microfiltration MF and ultrafiltration UF consistently remove suspended material and pathogens from drinking water; however, membrane fouling inhibits their application by increasing operation and maintenance costs. The impact of each configuration on floc properties, membrane fouling, and organics removal has been reviewed in detail. Due to relatively high membrane resistance and low NOM reductions, configuration Type 1 may not be optimal for fouling control and organics removal when compared to Types 2 and 3. Configuration Type 2 led to the lowest cake layer and specific cake layer resistance for both MF and UF, while there is evidence that Type 3 results in the greatest reduction in fouling rate by reducing mass flux towards the membrane surface. As expected, with no coagulant results indicate that UF achieves greater organics removal when compared to MF, but with the addition of coagulant performance is similar for all configuration types.
Sorry, this item can only be purchased by current members. Membrane systems, including microfiltration and ultrafiltration, will play a critical enabling role in meeting the challenges of water supply and wastewater treatment in the 21st century. The book will give practitioners a comprehensive understanding of all key facets of membranes and their design, application, and operation.
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