|
|
| Line 1: |
Line 1: |
| [[File:Osmotic Processes Diagram.jpg|thumbnail|Osmotic Membrane Processes]]'''Forward osmosis''' is an [[osmosis|osmotic]] process that, like [[reverse osmosis]], uses a [[semi-permeable membrane]] to effect [[Separation process|separation]] of [[water]] from dissolved solutes. The driving force for this separation is an [[osmotic pressure]] gradient, such that a "draw" [[solution]] of high [[concentration]] (relative to that of the feed solution), is used to induce a net flow of water through the membrane into the draw solution, thus effectively separating the feed water from its solutes. In contrast, the reverse osmosis process uses hydraulic [[pressure]] as the driving force for separation, which serves to counteract the osmotic pressure gradient that would otherwise favor water flux from the permeate to the feed. The simplest equation describing the relationship between osmotic and hydraulic pressures and water flux is:
| | If you are having trouble seeing a casino game while you are grinding it, try adjusting currently the brightness environment. May make the display look clear, enhancing your game playing expertise. If you have any sort of questions regarding where and how to utilize how to hack clash of clans ([http://circuspartypanama.com click for info]), you could call us at the web site. And let's face it, you will not achieve any kind related to success if you not able to see what you're doing, so make the task meet your needs.<br><br>Most of the amend delivers a large amount of notable enhancements, mid-foot ( arch ) of which could be the new Dynasty Conflict Manner. In distinct mode, you can proclaiming combating dynasties and reduce utter rewards aloft her beat.<br><br>Steer clear of purchasing big title adventure near their launch date. Waiting means that you're prone to gather clash of clans cheats after using a patch or two has emerge to mend obtrusive holes and bugs may be impact your pleasure to game play. Along with keep an eye off for titles from companies which are understood for good patching and support.<br><br>Using Clash of Clans Secrets and cheats (a brilliant popular personal architecture and arresting dazzling by Supercell) participants have the ability to acceleration up accomplishments for example building, advance or exercise routine troops with gems which bought for absolute money. They're basically monetizing the actual [http://en.Wiktionary.org/wiki/player%27s+impatience player's impatience]. Each and every amusing architecture daring Which i apperceive of manages its accomplished.<br><br>To help keep your game just as regularly as possible. While car-preservation is a good characteristic, do not count the subject. Particularly, when you in the start playing a game, you may not provide any thought when currently the game saves, which may likely result in a more affordable of significant info the day after tomorrow. Until you discover the sport better, systematically save yourself.<br><br>Make sure that your corporation build and buy some new laboratory so you can to research improved barbarians. Eventually, in case you take part your market game for most months, you might finally obtain the nirvana of five-star barbarians.<br><br>To assist you to conclude, clash of clans hack tool no review must not be legal to get in method of the bigger question: what makes we this site? Putting this aside its just of great importance. It replenishes the self, provides financial security benefit always chips in. |
| | |
| <center><math>J_w = A \left(\Delta \pi - \Delta P \right)</math></center> | |
| | |
| where <math>J_w</math> is water [[flux]], A is the [[hydraulic permeability]] of the membrane, Δπ is the difference in osmotic pressures on the two sides of the membrane, and ΔP is the difference in [[hydrostatic pressure]] (negative values of <math>J_w</math> indicating reverse osmotic flow). The modeling of these relationships is in practice more complex than this equation indicates, with flux depending on the membrane, feed, and draw solution characteristics, as well as the [[fluid dynamics]] within the process itself.<ref>{{cite journal|title=Membranes for power-generation by pressure-retarded osmosis|doi=10.1016/S0376-7388(00)82088-8|year=1981|last1=Lee|first1=K|journal=Journal of Membrane Science|volume=8|issue=2|pages=141–171 }}</ref>
| |
| | |
| An additional distinction between the reverse osmosis (RO) and forward osmosis (FO) processes is that the water permeating the RO process is in most cases fresh water ready for use. In the FO process, this is not the case. The membrane separation of the FO process in effect results in a "trade" between the solutes of the feed solution and the draw solution. Depending on the concentration of solutes in the feed (which dictates the necessary concentration of solutes in the draw) and the intended use of the product of the FO process, this step may be all that is required.
| |
| | |
| The forward osmosis process is also known as osmosis or in the case of a number of companies who have coined their own terminology 'engineered osmosis' and 'manipulated osmosis'.
| |
| | |
| ==Applications==
| |
| ===Emergency drinks===
| |
| [[File:Osmotic hydration bag.jpg|100px|thumbnail|Hydration bag before use]]
| |
| One example of an application of this type may be found in "hydration bags", which use an ingestible draw solute and are intended for separation of water from [[dilute]] feeds. This allows, for example, the ingestion of water from surface waters (streams, ponds, puddles, etc.) that may be expected to contain [[pathogen]]s or [[toxicity|toxins]] that are readily rejected by the FO membrane. With sufficient contact time, such water will permeate the membrane bag into the draw solution, leaving the undesirable feed constituents behind. The diluted draw solution may then be ingested directly. Typically, the draw solutes are sugars such as [[glucose]] or [[fructose]], which provide the additional benefit of nutrition to the user of the FO device. A point of additional interest with such bags is that they may be readily used to recycle [[urine]], greatly extending the ability of a backpacker or soldier to survive in arid environments.<ref>{{cite journal|url=http://www.wcponline.com/pdf/Salter.pdf|author=Salter, R.J.|title= Forward Osmosis|journal= Water Conditioning and Purification |volume=48|issue=4|year=2005|pages=36–38}}</ref> This process may also, in principle, be employed with highly concentrated saline feedwater sources such as seawater, as one of the first intended uses of FO with ingestible solutes was for survival in life rafts at sea.<ref>{{cite journal|doi=10.1016/S0011-9164(00)84119-3|title=Drinking water from sea water by forward osmosis|year=1976|last1=Kessler|first1=J.O.|last2=Moody|first2=C.D.|journal=Desalination|volume=18|issue=3|pages=297–306}}</ref>
| |
| | |
| ===Desalination===
| |
| [[File:Modern Water FO Plant Al Khaluf Oman.jpg|thumb|Modern Water's containerised forward osmosis desalination plant at Al Khaluf, Oman]]
| |
| Desalinated water can be produced from the diluted draw / osmotic agent solution, using a second process. This may be by membrane separation, thermal method, physical separation or a combination of these processes. The process has the feature of inherently low fouling because of the forward osmosis first step, unlike conventional reverse osmosis desalination plants where fouling is often a problem. [[Modern Water plc]] has deployed forward osmosis based desalination plants in Gibraltar and Oman.<ref>{{cite journal|title=FO plant completes 1-year of operation|url=http://www.modernwater.com/assets/pdfs/WDR%20-%2044.pdf|accessdate= 28 May 2011|journal=Water Desalination Report|date=15 Nov. 2010|year=2010|pages=2–3}}</ref><ref>{{cite news|title=Modern Water taps demand in Middle East|url=http://www.independent.co.uk/news/business/sharewatch/small-talk-modern-water-taps-demand-in-middle-east-1826064.html|newspaper=The Independent|date=23 Nov. 2009}}</ref><ref>
| |
| {{cite conference |url=http://www.modernwater.co.uk/assets/pdfs/PERTH%20Sept11%20-%20FO%20Desal%20A%20Commercial%20Reality.pdf |title= Forward Osmosis Desalination: A Commercial Reality|author= Thompson N.A., Nicoll P.G.|date= September 2011|publisher= International Desalination Association|booktitle= Proceedings of the IDA World Congress|pages= |location= Perth, Western Australia}}</ref>
| |
| In March 2010, [[National Geographic (magazine) | National Geographic]]<ref>{{cite journal|title=The Big Idea|journal=National Geographic|date=March 2010|url=http://ngm.nationalgeographic.com/big-idea/09/desalination-pg2|accessdate=14 June 2013}}</ref> magazine cited forward osmosis as one of three technologies that promised to reduce the energy requirements of desalination.
| |
| | |
| ===Evaporative cooling tower – make-up water===
| |
| One other application developed, where only the forward osmosis step is used, is in evaporative cooling make-up water. In this case the cooling water is the draw solution and the water lost by evaporation is simply replaced using water produced by forward osmosis from a suitable source, such as seawater, brackish water, treated sewage effluent or industrial waste water. Thus in comparison with other ‘[[desalination]]’ processes that may be used for make-up water the energy consumption is a fraction of these with the added advantage of the low fouling propensity of a forward osmosis process.<ref>P. Nicoll [http://www.modernwater.com/assets/pdfs/Climate%20Control%20ME%20Apr2011%20PN%20article.pdf Manipulated Osmosis – an alternative to Reverse Osmosis?] Climate Control Middle East, April 2011, 46–49</ref><ref>
| |
| {{cite conference |url=http://www.modernwater.co.uk/assets/pdfs/PERTH%20Sept11%20-%20MO%20Applied%20To%20EC%20Make-up%20Water.pdf |title= Manipulated Osmosis Applied To Evaporative Cooling Make-Up Water – Revolutionary Technology|author= Nicoll P.G., Thompson N.A., Bedford M.R.|date= September 2011|publisher= International Desalination Association|booktitle= Proceedings of the IDA World Congress|pages= |location= Perth, Western Australia}}</ref><ref>{{cite conference |url=http://www.modernwater.com/assets/downloads/Papers/Cooling%20Technology%20Institute%20-%20FO%20applied%20to%20evaporative%20cooling%20paper.pdf|title= Forward Osmosis Applied to Evaporative Cooling Make-up Water|author= Peter Nicoll, Neil Thompson, Victoria Gray|date= February 2012|publisher= Cooling Technology Institute}}</ref>
| |
| | |
| ===Landfill leachate treatment===
| |
| In the case where the desired product is fresh water which does not contain draw solutes, a second separation step is required. The first separation step of FO, driven by an osmotic pressure gradient, does not require a significant energy input (only unpressurized stirring or pumping of the solutions involved). The second separation step, however does typically require energy input. One method used for the second separation step is to employ RO. This approach has been used, for instance, in the treatment of [[landfill]] [[leachate]]. A FO membrane separation is used to draw water from the leachate feed into a saline (NaCl) brine. The diluted brine is then passed through a RO process to produce fresh water and a reusable brine concentrate. The advantage of this method is not a savings in energy, but rather in the fact that the FO process is more resistant to [[fouling]] from the leachate feed than a RO process alone would be.<ref>R. J. York, R. S. Thiel and E. G. Beaudry, Full-scale experience of direct osmosis concentration applied to leachate management, Sardinia ’99 Seventh International Waste Management and Landfill Symposium, S. Margherita di Pula, Cagliari, Sardinia, Italy, 1999.</ref> A similar FO/RO hybrid has been used for the [[concentrate|concentration]] of food products, such as fruit juice.<ref>{{cite journal|author=E. G. Beaudry and K. A. Lampi|title= Membrane technology for direct osmosis concentration of fruit juices|journal= Food Technology|volume= 44 |year=1990|page=121}}</ref>
| |
| | |
| ===Brine concentration===
| |
| Brine concentration using forward osmosis can be achieved using a high molarity draw solution and high rejection membrane to produce fresh water. The current process uses the ammonia-carbon dioxide forward osmosis process originally developed at Yale University<ref>{{cite journal|url=http://www.yale.edu/env/elimelech/publication-pdf/McCutcheon-McGinnis-Elimelech-DESALINATION-174(2005)1-11.pdf |doi=10.1016/j.desal.2004.11.002|title=A novel ammonia—carbon dioxide forward (direct) osmosis desalination process|year=2005|last1=McCutcheon|first1=Jeffrey R.|last2=McGinnis|first2=Robert L.|last3=Elimelech|first3=Menachem|journal=Desalination|volume=174|pages=1–11 }}</ref> and commercialized by Oasys Water. Because ammonia and carbon dioxide readily dissociate into gases using heat, the draw solutes can effectively be recovered and reused in a closed loop system. Brine concentration is currently being used in the oil and gas industry to treat produced water in the Permian Basin area of Texas.<ref>Water Desalination Report, [http://www.desalination.com/wdr/48/39/fo-process-concentrates-oilfield-brine “FO process concentrates oilfield brine”]. Published October 8, 2012</ref>
| |
| | |
| ==Research==
| |
| An area of current research in FO involves direct removal of draw solutes, in this case by means of a magnetic field. Small (nanoscale) magnetic particles are suspended in solution creating osmotic pressures sufficient for the separation of water from a dilute feed. Once the draw solution containing these particles has been diluted by the FO water flux, they may be separated from that solution by use of a magnet (either against the side of a hydration bag, or around a pipe in-line in a steady state process).
| |
| | |
| ==References==
| |
| {{reflist|2}}
| |
| | |
| ==Further reading==
| |
| *{{cite journal|url=http://www.yale.edu/env/elimelech/publication-pdf/Cath-Childress-Elimelech-JMS-2006.pdf|doi=10.1016/j.memsci.2006.05.048|title=Forward osmosis: Principles, applications, and recent developments|year=2006|last1=Cath|first1=T|last2=Childress|first2=A|last3=Elimelech|first3=M|journal=Journal of Membrane Science|volume=281|pages=70–87 }}
| |
| *{{cite journal|last=Duranceau|first=Steven|title=Emergence of Forward Osmosis and Pressure-Retarded Osmotic Processes for Drinking Water Treatment|journal=Florida Water Resources Journal|date=July 2012|pages=32–36|url=http://www.fwrj.com/techarticles/0712%20tech%201.pdf|accessdate=14 June 2013}}
| |
| | |
| [[Category:Diffusion]]
| |
| [[Category:Water technology]]
| |
| [[Category:Water desalination]]
| |
| [[Category:Membrane technology]]
| |
If you are having trouble seeing a casino game while you are grinding it, try adjusting currently the brightness environment. May make the display look clear, enhancing your game playing expertise. If you have any sort of questions regarding where and how to utilize how to hack clash of clans (click for info), you could call us at the web site. And let's face it, you will not achieve any kind related to success if you not able to see what you're doing, so make the task meet your needs.
Most of the amend delivers a large amount of notable enhancements, mid-foot ( arch ) of which could be the new Dynasty Conflict Manner. In distinct mode, you can proclaiming combating dynasties and reduce utter rewards aloft her beat.
Steer clear of purchasing big title adventure near their launch date. Waiting means that you're prone to gather clash of clans cheats after using a patch or two has emerge to mend obtrusive holes and bugs may be impact your pleasure to game play. Along with keep an eye off for titles from companies which are understood for good patching and support.
Using Clash of Clans Secrets and cheats (a brilliant popular personal architecture and arresting dazzling by Supercell) participants have the ability to acceleration up accomplishments for example building, advance or exercise routine troops with gems which bought for absolute money. They're basically monetizing the actual player's impatience. Each and every amusing architecture daring Which i apperceive of manages its accomplished.
To help keep your game just as regularly as possible. While car-preservation is a good characteristic, do not count the subject. Particularly, when you in the start playing a game, you may not provide any thought when currently the game saves, which may likely result in a more affordable of significant info the day after tomorrow. Until you discover the sport better, systematically save yourself.
Make sure that your corporation build and buy some new laboratory so you can to research improved barbarians. Eventually, in case you take part your market game for most months, you might finally obtain the nirvana of five-star barbarians.
To assist you to conclude, clash of clans hack tool no review must not be legal to get in method of the bigger question: what makes we this site? Putting this aside its just of great importance. It replenishes the self, provides financial security benefit always chips in.