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Water DesalinationPrestige World Wide
November 8, 2011
•Outline
Fresh Water SituationJohn Ross Norton
History of DesalinationPaige Guilbeaux
Economic FeasibilityJohn Ryan Davis
Environment and the Future of DesalinationBrandon Merril
1.
2.
5.
3.
4.
Desalination ProcessRachael Solari
Fresh Water SituationJohn Ross Norton
November 8, 2011
• 2/3 of the Earth is covered in water
• 2.5% is not salty• Of that fresh water, 2/3 is
contained in ice caps and glaciers
• 20% of that is in remote areas
• Much of what’s left comes as hurricanes and floods.
• Only 0.08% of all water is available to humans. [1]
•Global Availability
Image [2]
• Southwest- Lake Mead has dropped to half capacity. There is a bathtub ring 130 ft above the water’s surface along the canyon wall. [3]
• Midwest- Great lakes are shrinking as communities pull more and more from that resource.
• Northeast- Upstate New York reservoirs are seeing record lows. [4]
• Southeast- Atlanta’s water need is searching for a cure. Florida and Alabama believe Georgia has already taken more than its share of the Apalachicola-Chattahoochee-Flint river basin. [5]
US Issues
• 3 of top 10 cities facing water shortages are Houston, San Antonio and Fort Worth
• Lubbock- Meredith Depleted, Alan Henry
• Ogallala Aquifer heavily depleted
• Water table has dropped and not being recharged.
• Image [6]
•Texas
History of DesalinationPaige Guilbeaux
November 8, 2011
•What is water desalination?
•Process of removing various salts and minerals from water
•Used to convert salt water to fresh drinking water
http://6ssatnist.files.wordpress.com/2011/04/desalination.jpg
• Treated for taste• Heating, boiling, sand and gravel filtration
• Bag filter• “Hippocratic Sleeve”• Trap sediments
• Dark Ages• Water treatment took a step back
• Water Treatment Through the Years•History
2000 BC
500 BC
500 -1500
• Sir Francis Bacon experimented with sea water desalination
• Sand Filtration
• Invention of microscope• Water micro organisms first observed
• Chlorinated water• Large sand filters
• Water Treatment Through the Years•History
1627
1676
1890’s
First Desalination Plants – 1950’s
•History
http://web.mst.edu/~rogersda/umrcourses/ge342/http://www.toray.com/news/images/nr071210.gif
The Desalination ProcessRachael Solari
November 8, 2011
• 85% of worldwide production
• Boiling saline water and collection vapor
• Most common type of desalination process
• Semi-permeable membrane traps impurities
• Removal of salt by separating chemical components
• More suited for salty groundwater than seawater
•Desalination ProcessDifferent Types
• Multi-stage Flash Distillation
• Reverse Osmosis
• Electrodialysis
Stage 1•Salt water
is pumped through the heat exchangers and warms up
Stage 2•Reaches
brine heater and adds more heat
Stage 3•Sea water
is overheated compared to temp. and pressure of initial stage
Stage 4•Immediate
flash that releases heat and vapor to reach equilibrium
Stage 5•Produced
vapor is condensed into fresh water on tubular exchanger at each stage
Stage 6•Process
takes place from hot to last cold stage where fresh water build up is extracted
•Desalination ProcessMulti-stage Flash Distillation
•Desalination ProcessMulti-stage Flash Distillation
http://www.sidem-desalination.com/en/process/MSF/
Stage 1•Sea water is
pumped in and is mixed with fresh water
Stage 2•Enters into the
osmosis unit with a semipermeablemembrane
Stage 3•High pressure is
exerted on the high concentration side to overcome the osmotic pressure
Stage 4•High concentration
solvent is moved through membrane and is now usable.
•Desalination ProcessReverse Osmosis
•Desalination ProcessReverse Osmosis
1: Sea water inflow,2: Fresh water flow (40%),3: Concentrate flow (60%),4: Sea water flow (60%),5: Concentrate (drain),A: High pressure pump flow (40%),B: Circulation pump,C: Osmosis unit with membrane,D: Pressure exchanger
http://en.wikipedia.org/wiki/Reverse_osmosis
Desalination EconomicsJohn Ryan Davis
November 8, 2011
Facilities &
Capacity
Location
Feed water
Labor
Energy
Financing
Conc. Disposal
•Is Desalination economically feasible?Dominant Factors
• Proximity to the ocean• Elevation of consuming community
• Both contribute highly to the cost of transportation
• Desalination is more costly than other types of water treatment, such as recycled water
• Possibly only a solution for more prominent communities
•Economic Issues with DesalinationTechnologies’ costs are falling, but there are still some major
issues.
http://www.libraryindex.com/pages/2644/Arid‐West‐Where‐Water‐Scarce‐DESALINATION‐GROWING‐WATERSUPPLY‐SOURCE.html
DESALINATION
• Cost: $1000 - $4000 / acre-foot• Requires large amounts of
land, close proximity to coast
• Cost: $27 - $268 / acre-foot• Requires less land, located
almost anywhere
TRADITIONAL MEANS
•Desalination vs. Traditional Water SourcesAs the demand increases desalination can become competitive.
• During times of extreme drought costs of traditional water sources have increased to as much as $2300 / acre-foot.
Over 12,500 desalination plants worldwideMiddle East – 60%Saudi Arabia – 27 plants, 70% of their drinking water (2005)
Israeli Plant:Ashkelon Sea Water Reverse Osmosis Plant-Provides drinking water for 1.4 million people-Produces 108 million cubic meters per year
-Approximately 6% of the countries needed drinking water
•Desalination in the Middle East
http://www.ejpress.org/article/4873
Environment & the Future of DesalinationBrandon Merrill
November 8, 2011
• World population will increase by 2.5 billionin next 45 years
• Desalination water supply expected totriple between 2008 and 2020
• Countries with low rainfall totals have a high need for desalination because theycannot rely on groundwater
• Australia• Many African countries
•Why is Desalination needed?
Effect on the Ecosystem• Draining natural resources• Killing microbial and larvae
type organisms in theprocess
• Disposal of salt depositsand concentrate after theprocess is completed
• Enormous amounts of energy and pollutionexpelled in the process
• Wastewater management
•Environmental Concerns
• Forward Osmosis• Evaporation and
Condensation• Low-Temperature Thermal
Desalination (LTTD)• Thermo-Ionic Desalination• Higher Efficiency Plants• Solar Desalination Plants• More Efficient Membranes
• Nanotubes• Biomimetic
•Future Techniques & Improvements
• Increasing water conservation and water use efficiency is the most cost-effective means for increasing theamount of available water
• If plants and disposal processes can be improved, it makes desalination a viable option
• The increase in population willundoubtedly lead to an increasedwater shortage. The need fordesalination improvements isundeniable.
•Conclusion
Questions?Prestige World Wide
November 8, 2011
•References
[1] http://news.bbc.co.uk/2/hi/science/nature/755497.stm[2] http://www.worldwatercouncil.org/index.php?id=25[3] http://www.cbsnews.com/stories/2010/01/08/eveningnews/main6073416.shtml[4] http://www.naturalnews.com/022915.html[5] http://chronicle.augusta.com/news/government/elections/2010-05-18/new-governor-will-inherit-
georgias-water-crisis?v=1274226159[6] http://en.wikipedia.org/wiki/Ogallala_Aquifer[7] http://en.wikipedia.org/wiki/Desalination[8] http://www.lenntech.com/history-water-treatment.htm[9] http://www.goldcoast.qld.gov.au/attachment/goldcoastwater/EBWS_FS4.pdf[10] http://en.wikipedia.org/wiki/Desalination[11] http://www.ejpress.org/article/4873[12] http://www.libraryindex.com/pages/2644/Arid‐West‐Where‐Water‐Scarce‐DESALINATION‐GROWING‐
WATERSUPPLY‐SOURCE.html