Katapodis.Flynn.wiki.spring.2011

=Water Desalination=

====Water is the biggest essential for all living things on earth, but sometimes there is not enough to go around. This is a problem the world has, there is over 6.3 billion people in the world and lots of areas in the world are in high demand for water. About 97% of the worlds water is in the ocean, with about 35,000 ppm(parts per million) of salt. That means only 3% of the worlds water is considered fresh water. There is less than one percent of water that is considered safe for people to drink, (with less than 1000ppm). For arid areas they do not have fresh water sources such as lakes and river, and if area have a fresh water sources they usually are highly polluted. The low abundance of fresh water resources and the need for additional water supplies is already extremely in many arid regions of the world and will be more important in the future. It is very likely that the water issue will be considered just like fossil fuels resources. Without water countries would not be able to move forward economically.==== ====Water is the center of many conflicts in developing nations, which are being hit hard by the lack of water. The growing population and climate change play into this water crisis. The population is always growing, making there be a greater demand for food, and other products produced from agriculture and industry. Agriculture uses 70% of the world’s fresh water, industry uses 22%, and only 8% is used for domestic purposes. This means that agriculture and industry will continue to use more of the precious water supply as the world’s population grows. Climate change is also affecting the water crisis. As temperatures increase, so does the melting rate of glaciers and the built up snow from winter. For many regions in the world this is the main way to obtain water. With rising temperatures and melting happen faster, this leads to the runoff running dry during the summer months when it is needed most. Global warming also disrupts the flow patterns of water, which can lead to an increase in the severity of floods, storms, and droughts. With less access to water, villagers in remote regions must walk further to get safe water. People in urban environments are affected by the diseases that come with drinking unsanitary water.====

> ===="Water is the oil of the 21st century"–Andrew Liveris, CEO Dow Chemical,==== > ====cited in “Running Dry,” //The Economist//, 21 Aug 08====



**Worlds water scarcity and water stress.**



====One way water could be produced is through a process called "water desalination". This process is not new by any means many ancient civilizations used this method on their ships to supply water to the crew manning them. With 97% of the world’s water being saltwater, desalination could be a very real solution to the water crisis. One of the downsides of desalination is that on the large scale, it requires a lot of energy. It also requires very elaborate, expensive infrastructure, making it a very costly procedure. Desalination is one of the only renewable water sources that does not depend on rainfall. The world's largest plant is the Jebel Ali Desalination Plant in the United Arab Emirates. This is a dual purpose facility that produces 300 million cubic meters of water per year by utilizing multi-stage flash distillation. In the United States, desalination is used heavily by two states, California and Florida. California has over Thirty plants, which allows water to be pipelined all over the state. Also it allows the golden state to rely less on the Colorado River, around 180 billion less gallons were taken from the river. Florida, With more than 120 plants in Florida, it leads the nation in desalination ( Texas with around 38 and California with around 33.====



Different types of Desalination

====The first type of Desalination is the good old fashion way of Distillation, boiling water and catching the water vapors and letting it from back into a liquid state. This happens by adding a heat source to the water( sun, fire, oil, or natural gas, etc.) The heat source will cause the non-drinkable water to evaporate, as the water evaporates it leave all other contaminates behind. After the evaporation has taken place the gas will collect into a chamber where a cooling liquid will run over the chamber letting the vapors turn back into condensation, where then it will be collected as clean drinking water.====

====The second type of Desalination that could be used is Reverse Osmosis through a semipermeable membrane. This process is where salt water would be put under pressure and using the membrane to create reverse osmosis. In doing this the membrane catches ions, large organics particles, and bacteria trying to pass through them. RO membranes can even retain small ions such as sodium, chlorine, calcium, and magnesium. The particle that is not allowed to pass throught the membrane. The membranes come in different configurations. They can be spiral wound, or hollow fibers. They are usually made of cellulose acetate, aromatic polyamides, or thin polymer composite film.====

spiral wound reverse osmosis Hollow fiber reverse osmosis

SOLAR STILLS
====Another simple use of solar energy in desalination comes from solar stills. There are many shapes for solar stills, also can be known as distillation stills. A water cycle is created within panes of glass when the sun evaporates seawater input, water vapor condenses on the underside of the glass, and is guided into troughs as freshwater. Different to solar ponds, solar stills come with the advantage that there is no concern for water loss through evaporation, but its productivity depends on temperature and sun intensity.====



-Provides completely safe drinking water.
====CONS- Desalination process creates a lot of brine water. Brine water is concentrate that is removed from water during desalination, has traditionally been deposited in landfills or oceans, but this is not an environmentally friendly plan for the next 100 years. Simply dumping the brine into the ocean as is tradition for some facilities will create chaos for organisms living in the water that may be used to the homogenous conditions of the water. Not only does brine have environmental impacts but also efficiency issues.====

Critics
====The critics would say that this is a very useful technique of getting water and will be very useful if the production cost goes down to produce clean drinking water. Also that the processing plants needs to be much more energy proficient. Another thing is we should be recycling waste water more and trying to use less because its cheaper and much easier. For the brine to be disposed in a proper matter without hurting the environment, to also turn the brine into a bigger profit or find other useful things for it.====

What would WE do!
After learning about Desalination, we found out about the importance of it and how it can save many lives. Things we would change would be definitely be the amount of energy that is lost. To create less CO2 emissions would be great and doing it for a lower price would be great right now with the economy. Also we would have the plants run more on recycled fuel and energy. Also we would find a suitable use for the brine left over from the process, so that it is more beneficial to us and friendly to the environment. Other than that we believe desalination has real potential to provide the world with clean, dependable drinking water.

This project was done by Tom "Huckleberry" Flynn & Alex "KAT DING" Katapodis

WORK CITED
http://ga.water.usgs.gov/edu/drinkseawater.html

ttp://ga.water.usgs.gov/edu/waterdistribution.html . http://www.cee.vt.edu/ewr/environmental/teach/wtprimer/desalt/desalt.html

http://web.mit.edu/12.000/www/m2012/finalwebsite/solution/desal.shtml

http://www.sfwmd.gov/portal/page/portal/pg_grp_sfwmd_watersupply/subtabs%20-%20water%20conservatio%20%20-%20brackish/tab1610173/sfwmd%20desalination%20frequently%20asked%20questions.pdf