At the membrane surface, the permeating component moves perpendicularly to the membrane surface. The figure shows the size of components passing each type of membrane. Gas separation across a membrane is a pressure driven process, where the driving force is the difference in pressure between inlet of raw material and outlet of product. Applied to dairy products, the separation techniques allow valuable compounds, found in milk, to be isolated for use as ingredients in food processing. Effects of feed concentration, operating pressure, ph and existing ions on asv removal were investigated. These include forward osmosis fo, which has potential for wastewater purification and desalination, and. The first section of the text covers characteristics of membrane separation processes, mass transfer membrane processes, and concentration polarization. In odmps, the operating conditions and membrane properties play more critical roles in mass transport and process performance than in pressuredriven membrane processes. Membrane processing is a filtration technique in which particles are separated from liquids by being forced through a porous material, or membrane. By applying pressure the water flows through the membrane and components with a certain size are retained. In general, mechanical separation processes for separating gaseous or liquid streams use membrane technology. Itrc pressuredriven membrane separation technology. Transport of mass and mechanical energy can be expresses as follows.
Fundamentals of pressuredriven membrane separation processes. Pressure dependency of the membrane structure parameter and implications in pressure retarded osmosis pro, osmotically driven membrane processes approach, development and current status, hongbo du, audie thompson and xinying wang, intechopen, doi. Pressuredriven membrane filtration processes synder filtration. Cold separation using membrane technology is widely used in the food technology, biotechnology and. Membrane systems are unit processes that are becoming widely accepted for the demineralization of saline and other waste waters. Membrane processing for dairy ingredient separation wiley. Characterization of fouling potential for pressuredriven. It is not used as much in large water treatment facilities as some of the other technologies described here. Jaffrinc a ea 4297 timr, technological university of compiegne, 60205 compiegne cedex, france. Membrane separation processes operate without heating and therefore use less energy than conventional thermal separation processes such as distillation, sublimation or crystallization. Ultrafiltration is also a membrane separation process driven by pressure.
While reverse osmosis membranes are nonporous and therefore, permeable only to very small molecules, ultrafiltration membranes are microporous and permeable to small solute species in addition to the solvent. Membrane operation parameters separation processes. Free awwa mtc53942 standard pdf and download in canada. The available pdms processes are primarily distinguished from each other in terms of the molecular size of the contaminants of solutes that they will remove. A comparison between dead end and tangential flow filtration tff is made and the limitations of tff due to concentration polarization and membrane fouling are.
During the last two decades, pressure driven membrane processes,namelyreverseosmosisro,nanofiltrationnf, and ultrafiltration uf, have found increased applications in water utilities and chemical industries. Jun 29, 2015 membrane processing is a filtration technique in which particles are separated from liquids by being forced through a porous material, or membrane. The modes of operation of pressure driven membrane processes, concentration, diafiltration and purification, are also analysed. Pressure driven membrane processes addeddate 20171127 11. Flux, transmembrane pressure, osmotic pressure, osmotic pressure model, resistance towards mass transport, concentration polarization, gel layer model, and membrane fouling are all important terms that are explained and described. The principles of the pressure membrane processes are shown in figure 1. Mf and uf are pressuredriven membrane processes that use microporous membranes to remove particulate matter including turbidity and microorganisms, via a sieving mechanism, on the basis of size exclusion. Hierarchy of pressure driven membrane processes 3 2. Membrane processes reverse osmosis is a pressure driven process which forces saline water through a. The cells use different methods of transport, depending on the nature of the.
Membrane transport questions and study guide quizlet. Osmotically driven membrane processes approach, development. Pressure driven membrane processes low pressure membranes microfiltration mf and ultrafiltration uf high pressure membranes reverse osmosis ro and nanofiltration nf current driven membrane processes. Basics of membrane technology viatcheslav freger wolfson department of chemical engineering thitechnion ilisrael itittinstitute of th ltechnology, hifhaifa, ilisrael zero liquid discharge workshop, gandhinagar, january 27. Most pressuredriven membrane processes are operated in the crossflow fltration mode. Typically occurring problems like membrane fouling and possible optimizations of the described membrane processes are discussed. Pdf the paper presents usefulness of membrane processes ultrafiltration uf and nanofiltration nf for treatment of backwashing water of. The importance of specification sheets for pressuredriven. Effects of solute permeability on permeation and solute. The hydraulic pressure plays an important role in the osmotically driven membrane processes.
Pressuredriven membrane processes are commonly divided into four overlapping categories of increasing selectivity. Pressure driven membrane processes include microfiltration, ultrafiltration, nanofiltration and. In this text we will focus on the pressure driven membrane processes, in which the flux through the membrane is induced by a hydrostatic pressure difference between the bulk solution and the permeate side. Dead end membrane filtration michigan state university. In pressuredriven membrane processes reverse osmosis, nanofiltration, ultrafiltration, and microfiltration a pressure exerted on the solution at one side of the. Electrically driven membrane processes are widely used to remove charged components from a given feed solution or suspension. Differs from all other membrane processes because of the phase changeof the permeate.
Pressure driven membrane processes include microfiltration, ultrafiltration, nanofiltration and reverse osmosis. Effect of molecular weight of draw solute on water. Membrane processes do not require heating, which makes the process suitable for the treatment of thermolabile products. Comparison of removal characteristics of different pressuredriven membrane processes. In the deadend mode, one stream of the feed enters the membrane module and flows vertically toward the membrane surface, and only one stream leaves the membrane module. It is demonstrated in this study that the hydraulic pressures applied on the feed solution and draw. Osmotically driven membrane processes odmps such as forward osmosis fo and pressure retarded osmosis pro are extensively investigated for utilization in a broad range of applications. In this virtual issue, various membrane applications are presented ranging from wastewater treatment, e. In odmps, the operating conditions and membrane properties play more critical roles in mass transport and process performance than in pressure driven membrane processes. Pressure driven membrane processes 6 in this text we will focus on the pressure driven membrane processes, in which the flux through the membrane is induced by a hydrostatic pressure difference between the bulk solution and the permeate side.
Membrane technology covers all engineering approaches for the transport of substances between two fractions with the help of permeable membranes. Its main difference from reverse osmosis is the type of membrane used. Additional resources and features associated with this. Even though membrane processes are a relatively new type of separation technology, several membrane processes, particularly pressuredriven membrane processes including reverse osmosis ro, nanofiltration nf, ultrafiltration uf, and microfiltration mf, are already applied on an industrial scale to food and bioproduct processing.
A selfmade pmia asymmetric nanofiltration membrane was used for arsenic removal from drinking water by nf process. Safe drinking water is essential membrane processes. Following on from the work presented in part i, this part ii paper presents a new mathematical description for water and solute transfer in pressure driven membrane separation processes, the. Pressure driven membrane processes table 3l gives an overview of the four pressure driven membrane processes mentioned above. Fundamentals of pressuredriven membrane separation. Charged ions and all other materials greater than or equal to.
The four main methods of pressuredriven membrane filtration are microfiltration, ultrafiltration, nanofiltration, and reverse osmosis, in order of decreasing pore. Find answers to all your questions in our free books. In these processes, the separation of a solute or dispersed matter from a liquid stream is carried out by forcing the liquid through the membrane, using a pressure difference as the driving force. Engineering aspects of membrane separation and application.
The core is the membrane it self, through which a driving force induces a flux from the bulk to the permeate side. Pressure driven membrane processes hailienene foundation. Pressure driven, membranebased technologies ro, nf, uf all suffer from fouling, which affects desalination and other water treatment procedures, and comprises deposition on the membrane surface andor in its pores, reducing its salt rejection and water flux. The separation process is purely physical and both fractions permeate and retentate can be used. To address the increasingly severe global water shortage and pollution problem, reverse osmosis ro has been widely used because of its ability to produce high quality water. Comparison of membrane modules system advantages disadvantages flat sheet 1. Actually pressuredriven membrane processes can be operated in two dif ferent modes. Ultrafiltration uf is a pressuredriven barrier to suspended solids, bacteria, viruses, endotoxins and other pathogens to produce water with very high purity and low silt density. The core in every membrane process is, thus, the membrane that allows certain. Pressure dependency of the membrane structure parameter and. Even though membrane processes are a relatively new type of separation technology, several membrane processes, particularly pressure driven membrane processes including reverse osmosis ro, nanofiltration nf, ultrafiltration uf, and microfiltration mf, are already applied on an industrial scale to food and bioproduct processing. Table 64 comparison of various pressure driven membrane processes. Osmotically driven membrane processes odmps including forward osmosis fo and pressure retarded osmosis pro have attracted increasing attention in fields such as water treatment, desalination, power generation, and life science. Electrodialysis combines membrane technology with the application of electrical current, to separate contaminants based on charge.
Membrane water treatment systems were originally used only in desalination projects. Mass transfer in pressuredriven membrane separation. Forward osmosis fo membrane processes have attracted much research interest because of their versatile potential application in water treatment. Unlike ro, nf, and uf, donnan membrane process or donnan dialysis is driven by the electrochemical potential gradient across the. Reuse, treatment, and discharge of the concentrate of. As follows from what has been said above, the use of pdmp is desirable for very diverse technological problems existing in pharmaceutical chemical factories and in research work, while at the present time isotropic membrane filters are mainly used in processes of fine and sterile filtration, anisotropic membranes and the corresponding equipment must be produced for the wider introduction of. Meanwhile, related technologies have been developed, called osmotically driven membrane processes odmps. Membrane desalination technologies in water treatment. Fundamentals of pressuredriven membrane separation processes this chapter presents some basic concepts related to. The most broadly applied types of membrane filtration are pressure driven processes and include reverse osmosis ro, nanofiltration q. Chemical engineering books are you a chemical engineering student. Applications of membrane processes to the downstream processing of biological products are presented, namely cell harvesting by micrifiltration, protein transmission and recovery from whole fermentation broths and cell.
Membrane processes widely studied as a means of desalting brackish or seawater. Actually pressuredriven membrane processes can be operated in two different modes. Unlike other membrane processes, the source water never passes through the membranes during electrodialysis. The book describes both pressure driven traditional processes, such as nanofiltration, reverse osmosis, ultrafiltration, etc and more advanced membrane processes such as forward osmosis, membrane distillation, and membrane bioreactors employed in the application of interest. Pressure driven membrane processes calculations here we give some important calculation tools for the successfull development of membrane processes. The most extensively used membrane material is cellulose acetate though an aromatic polyamide is also used. The core in a membrane process is a membrane that allows certain components to pass while retaining other components. In contrast to pressure driven membrane processes, e. Thus the applied driving force is a voltage difference and the components that are removed are ions. This book presents the principles and applications of these techniques. Basics of membrane technology gujarat pollution control. Arsenic removal from drinking water by selfmade pmia. In contrast to pressuredriven membrane processes, e.
The membrane used in the process is a generally nonporous layer, so there will not be a severe leakage of gas through the membrane. The properties of modern membrane technology make it suitable for applications in the food industry. Dissolved and particulate material, specifically colloidal matter, present in the feed stream to membrane systems are considered the principal causes of membrane fouling and reduced efficiency. Jaffrin c a ea 4297 timr, technological university of compiegne, 60205 compiegne cedex, france.
The pressure driven membrane processes discussed in this fact sheet are microfiltration mf, ultrafiltration uf, nanofiltration nf, and reverse osmosis ro. Natural sciences science and nature books bookboon. Pressure driven membrane processes 4 summary basic terms and equations used in membrane technology have been presented and explained. In contrast to pressure driven membrane processes where you have a volume flux through the membrane. Pressure driven membrane processes pdf free download. Thus the term dxdx in equation 1 can be replaced by p which is the difference between the pressure of the bulk side and the permeate side. The osmotic pressure term, which often plays a great role in pressure driven membrane processes, has been discussed and equations for calculating the osmotic pressure for different feed solutions are given.
Ultrafiltration uf is a variety of membrane filtration in which hydrostatic pressure forces a liquid against a semi permeable membrane. Pdf mass transfer in pressuredriven membrane separation. Standard methodology for evaluating membrane performance. The size of separated particles or molecules and chemical properties of the solvent are critical in the selection of the appropriate membrane type. Simulation of reverse osmosis and osmotically driven. Pressure driven membrane processes have proven to be significantly more energy efficient than their thermal counterparts. Pressuredriven membrane process an overview sciencedirect. In addition the relatively low capital and operating costs involved make membrane processes an appealing alternative to more conventional separation processes, particularly when dealing with dilute solutions. Applied to dairy products, the separation techniques allow valuable compounds, found in milk, to be.
Microfiltration, ultrafiltration, nanofiltration and reversed osmosis are pressure driven processes. Pressure driven membrane processes have become a wellestablished technology in many industrial applications. Standard methodology for evaluating membrane performance in. The pressuredriven membrane processes discussed in this fact sheet are microfiltration mf, ultrafiltration uf, nanofiltration nf, and reverse osmosis ro. Membrane processing for dairy ingredient separation.
They will help to calculate the results of whole membrane processes based on measurement results from lab tests. Pressure driven membrane processes are used in the food, biotech, bio chemical pharmaceutical and many other industries. The pressure membrane processes are used to concentrate or refine diluted solutions and dispersions. But improvements in membrane technology have made them an increasingly popular choice for removing microorganisms, particulates, and natural organic materials that foul waters taste and taint its clarity. Membrane filtration rochester institute of technology. Aug 02, 2003 application of pressure driven membrane processes microfiltration, ultrafiltration, nanofiltration, and reverse osmosis results in the generation of a large concentrated waste stream, the concentrate fraction, as a byproduct of the purification process. A membrane process is capable of performing a certain separation by use of a membrane. Mar 15, 2011 read mass transfer in pressuredriven membrane separation processes, part ii, chemical engineering journal on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Osmotically driven membrane processes odmps including forward osmosis fo and pressureretarded osmosis pro have attracted increasing attention in fields such as water treatment, desalination, power generation, and life science. In this process, the feed solution flows tangentially to the membrane surface. Furthermore, the lower specific energy consumption of oaro in comparison to other chemically driven membrane processes, such as fopafo, make it an economically viable process addition for brine volume minimisation. Experimental results showed that asv rejection was higher than 90% in the range of investigated as feed concentrations. Pressure driven membrane processes 4 1 introduction pressure driven membrane processes are widely used in almost all kinds of chemical, pharmaceutical, food and dairy industries.