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Water Desalination With Nanotechnology

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Chiuyin Cheung

on 27 May 2011

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Transcript of Water Desalination With Nanotechnology

Water Desalination using Nanotechnology Group 7 Kira Lin Chiu Yin Cheung G Period Overview 1 out of 8 have no access to clean water 2400 children die due to dirty water EVERY DAY in 20 years, the demand for clean water will outweigh supply by 40% of all the water on earth, only 0.68% is recoverable freshwater 97% of all water on earth
is recoverable seawater compared to Water H O H water sea H2O H2O H2O H2O H2O H2O H2O H2O H2O H2O H2O H2O Na+ Cl- K+ K+ K+ Na+ Na+ Na+ Na+ Na+ Cl- Cl- Cl- H2O H2O H2O H2O H2O H2O H2O H2O Traditional Desalination Expensive Specialized Infrastructure High energy consumption costs 10x more than drawing freshwater from underground (U.S. Geological Survey, 2011) large scale water desalination requires very specific & expensive plants to be built oil-rich middle east (Pacific Institute, 2009) can afford the high energy costs Modern Desalination Ion Concentration Polarization Graphene Filter Graphene Filters cutting-edge technology What is graphene? carbon atoms 1 atom thick honeycomb lattice How is graphene prepared for desalination? (Zettl et al, 2009) Graphene sheet is shot with a beam of electrons A hole is punched in the sheet The hole can be 0.75nm to 2.75nm wide (Suk, Aluru, 2010) How does graphene desalinate water? filters unwanted salts from water holes created in sheet can be larger than H2O Na+ Cl- K+ O H H increasing molecular/atomic size but smaller than Na+ ions works like a sieve Ion Concentration Polarization Why is graphene a good material for desalination? On the inside (Fox, 2010) (Kim, Ko, Kang, Han, 2010) (Chicken Coop Building Ideas, 2009) (Edaxicon, 2011) Seawater enters the device observe the thinness of the graphene filter (Suk, Aluru, 2010) Compact High Selectivity The water does not
need a motor to be pushed
through the device,
uses gravity Hole in sheet of graphene tailored for water molecules to pass in a single file (Suk, Aluru, 2010) ion selective membrane only allows water through Other ions get pushed away poor countries with water problems have little access to desalination Future Developments Research Long Term Short Term large scale energy efficient cheap to operate desalination for large communities of people Low Water Pressure (Suk, Aluru, 2010) Graphene has a Greater water flux than its nearest competitor Graphene has a greater water flow lower water pressure required to drive water over filter catalysts to produce consistent quality sheets of graphene processes to ensure consistent pore size engineer a 1 step approach to water purification bacteria
organic materials
heavy metals Bibliography - Primary Sources Multi-Stage Flash Desalination (democraticunderground.com, 2006) (Sidem, 2010) 16th Century European sailors desalinate seawater
by boiling it over furnaces 1850 American Norbert Rilleux engineers new method
to remove water from sugar cane. His method
"Multiple Effect Distilliation" refines sugar 1890s How it Works Multiple Effect Distillation makes its way into
the water desalination industry. First used in steamships & Yemen and Sudan 1950s New process "Multi Stage Desalination" solves
the problems of Multiple Effect Desalination Reduces mineral buildup in heating chambers 1960 "Reverse Osmosis" invented at UCLA Removes salts from water with membrane No heating required Seawater flows through tubes
above the chambers, while being
heated Most widely used process today Starting from the warmest chamber,
and ending at the coolest. The hot seawater enters the first chamber The seawater "flashes" evaporates into a
freshwater vapor 2010 "Ion Concentration Polarization" desalination
engineered at MIT Uses electric fields to separate charged salts from water MARCH 2010 APRIL Graphene is engineered for use in desalination Sieves out salts on the atomic level The seawater flows into the
next chamber Bibliography - Secondary Sources Kim, Sung Jae, Sung Hee Ko, Kwan Hyoung Kang, and Jongyoon Han. "Direct Seawater Desalination by Ion Concentration Polarization : Abstract : Nature Nanotechnology."Nature Publishing Group : Science Journals, Jobs, and Information. Nature Nanotechnology, 21 Mar. 2010. Web. 19 May 2011. . Suk, Myung E., and N. R. Aluru. "Water Transport through Ultrathin Graphene."Pubs.acs.org/JPCL. The Journal of Physical Chemistry Letters, 30 Apr. 2011. Web. 19 May 2011. . Reverse Osmosis membrane Chandler, David L. "A System That's Worth Its Salt." MIT News. Massachusetts Institute of Technology, 23 Mar. 2010. Web. 19 May 2011. . Fox, Stuart. "Breakthrough Low-Power Desalination and Purification Technology Brings Clean Water To Remote Villages." PopSci. 23 Mar. 2010. Web. 19 May 2011. (Economist, 2009) Scheer, Roddy. "Trickle Down: Is Access to Clean Water a Human Right?: Scientific American." Science News, Articles and Information | Scientific American. 6 Apr. 2011. Web. 19 May 2011. . explained later structure of graphene Sidem. "MSF - Multi-stage Flash Distillation Process." Sidem Thermal Desalination EPC Contractor. Sidem, 2010. Web. 27 May 2011. . (Thinkquest, 2009) (Shankbone, 2009) (Han, 2010) (Sidem,2010) (Kim, Ko, Kang, Han, 2010) (Fox, 2010) (Chandler, 2010) Portable Cheap Hand-Operated desalination mechanisms for personal use (Suk, Aluru, 2010) "Tapping the oceans." The Economist, 2009. Web. 25 May 2011. A True Story (Charity:Water, 2011) END "Will the Beautiful Women in the World Please Stand Up." Charity:Water, 2009. Web. 24 May 2011 (U.S. Geological Survey) (Economist, 2009) (United Nations, 2009) (United Nations, 2009) (Scheer, 2011) "Majority of world population face water shortages unless action taken, warns Migiro." United Nations News Service. 2009. Web. 25 May 2011. (Suk, Aluru, 2010) (Utilities-me, 2010)
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