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