Desalination Research Paper
Desalination of Water
While renewable, the world’s water supply is being depleted faster than it is being refilled. This has caused ¼ of the global economy to be at risk because of non-sustainable water use. A solution to the unsustainable water crisis is desalination. 97% of all water on Earth is non-usable salt water. The other 3% is fresh, usable water, however ~68% of that water is locked up in glaciers, and 30% is stored in underground aquifers. The remaining 1-2% comes from things such as ground ice, fresh water lakes, and rivers. Desalination (the removal of salt) would allow water to be consumed from an almost fully renewable source, the oceans. As it stands, today we face the risk of running out of usable water; rivers are running …show more content…
dry, and underground aquifers are being drained faster than they refill. By 2050, the population will grow to 9 billion, requiring more water to be used in agriculture, industry, and by people.
Desalination is a process that is already beginning to occur around the world in places including the US and (most notably) the Middle East.
Over 50% of renewable water in the Middle East has been used, and therefore desalination is more common in those areas. The most common processes of desalination are osmosis and multistage flash distillation. Saudi Arabia has multistage flash distillation plants as well as osmosis plants for desalination. Places that require desalination most are dry, coastal areas. In the US, the largest desalination plant is located in Florida, but other states such as Texas and California are also beginning to develop desalination …show more content…
plants.
As mentioned above, there are two main procedures for desalinating water – osmosis and multistage flash distillation. There are two ways in which osmosis can be used to desalinate water, reverse osmosis and forward osmosis. Of the two, reverse osmosis is the one used more frequently.
In reverse osmosis, pressure is used to move water through a membrane, which prevents the larger salt molecules from passing through. Of all the large-scale desalination processes, reverse osmosis is considered to be the least energy consuming. A major setback of using reverse osmosis is the fact that bacteria can clog the membrane, and the chlorine used to treat the bacteria causes the membrane to deteriorate. Along with the membrane issue, there is controversy over the quality of the water produced, and the considerable pre-treatment of the salt water. Despite these downsides, reverse osmosis is the leading desalination technique today.
Forward (or regular) osmosis, the natural osmosis process, is another way to desalinate water. Osmosis is the process of a substance moving from an area of low concentration to an area of high concentration. In this process, seawater naturally moves across a membrane to a concentrated solution of ammonia salts, leaving the sea salt on the other side of the membrane. The solution with the ammonia salts is then heated, evaporating the ammonia salts (which are reusable). Regular osmosis costs about half as much as reverse osmosis due to the fact that less energy is required to complete the process, however it is a newer large-scale technique, and requires more research and funding in order to make improvements and reduce energy costs.
Multistage flash distillation, previously the leader in desalination methods, has to do with repeatedly heating the solution – heated water is heated again and again, each time on a lower pressure than before.
The multistage flash distillation plants are placed next to power plants in order to use their wasted heat. The major downsides of multistage flash distillation are the fact that it requires a larger intake of salt water than reverse and forward osmosis, and the upfront and maintenance costs are very high.
As we continue to deplete the world of its naturally fresh water, more time, energy and research will be going into developing ways to access fresh water from the most abundant source of water on the planet – oceans. Although there are downsides (just like most technological advancements), desalination will play a key role in sustaining industry and the population as things such as underground aquifers, rivers, and lakes run dry.
Alon Tal, (2011). The Desalination Debate. . 53 (), pp.
Bhausaheb L. Pangarkar, Mukund G. Sane, and Mahendra Guddad, (2011). Reverse Osmosis and Membrane Distillation for Desalination of Groundwater: A Review. . 2011 (), pp.
Khamis (e.g. 2011). Nuclear Desalination. [ONLINE] Available at: http://www.world-nuclear.org/info/Non-Power-Nuclear-Applications/Industry/Nuclear-Desalination/#.UT17CY5c_ww. [Last Accessed March 6 2013]
Marek Gryta, (2012). Effectiveness of Water Desalination by Membrane
Distillation Process. membranes.
(), pp.
Xanthe Webb Aintablian (2011). Water Desalination. [ONLINE] Available at: http://geography.about.com/od/waterandice/a/Water-Desalination.htm. [Last Accessed March 2 2013].
While renewable, the world’s water supply is being depleted faster than it is being refilled. This has caused ¼ of the global economy to be at risk because of non-sustainable water use. A solution to the unsustainable water crisis is desalination. 97% of all water on Earth is non-usable salt water. The other 3% is fresh, usable water, however ~68% of that water is locked up in glaciers, and 30% is stored in underground aquifers. The remaining 1-2% comes from things such as ground ice, fresh water lakes, and rivers. Desalination (the removal of salt) would allow water to be consumed from an almost fully renewable source, the oceans. As it stands, today we face the risk of running out of usable water; rivers are running …show more content…
dry, and underground aquifers are being drained faster than they refill. By 2050, the population will grow to 9 billion, requiring more water to be used in agriculture, industry, and by people.
Desalination is a process that is already beginning to occur around the world in places including the US and (most notably) the Middle East.
Over 50% of renewable water in the Middle East has been used, and therefore desalination is more common in those areas. The most common processes of desalination are osmosis and multistage flash distillation. Saudi Arabia has multistage flash distillation plants as well as osmosis plants for desalination. Places that require desalination most are dry, coastal areas. In the US, the largest desalination plant is located in Florida, but other states such as Texas and California are also beginning to develop desalination …show more content…
plants.
As mentioned above, there are two main procedures for desalinating water – osmosis and multistage flash distillation. There are two ways in which osmosis can be used to desalinate water, reverse osmosis and forward osmosis. Of the two, reverse osmosis is the one used more frequently.
In reverse osmosis, pressure is used to move water through a membrane, which prevents the larger salt molecules from passing through. Of all the large-scale desalination processes, reverse osmosis is considered to be the least energy consuming. A major setback of using reverse osmosis is the fact that bacteria can clog the membrane, and the chlorine used to treat the bacteria causes the membrane to deteriorate. Along with the membrane issue, there is controversy over the quality of the water produced, and the considerable pre-treatment of the salt water. Despite these downsides, reverse osmosis is the leading desalination technique today.
Forward (or regular) osmosis, the natural osmosis process, is another way to desalinate water. Osmosis is the process of a substance moving from an area of low concentration to an area of high concentration. In this process, seawater naturally moves across a membrane to a concentrated solution of ammonia salts, leaving the sea salt on the other side of the membrane. The solution with the ammonia salts is then heated, evaporating the ammonia salts (which are reusable). Regular osmosis costs about half as much as reverse osmosis due to the fact that less energy is required to complete the process, however it is a newer large-scale technique, and requires more research and funding in order to make improvements and reduce energy costs.
Multistage flash distillation, previously the leader in desalination methods, has to do with repeatedly heating the solution – heated water is heated again and again, each time on a lower pressure than before.
The multistage flash distillation plants are placed next to power plants in order to use their wasted heat. The major downsides of multistage flash distillation are the fact that it requires a larger intake of salt water than reverse and forward osmosis, and the upfront and maintenance costs are very high.
As we continue to deplete the world of its naturally fresh water, more time, energy and research will be going into developing ways to access fresh water from the most abundant source of water on the planet – oceans. Although there are downsides (just like most technological advancements), desalination will play a key role in sustaining industry and the population as things such as underground aquifers, rivers, and lakes run dry.
Alon Tal, (2011). The Desalination Debate. . 53 (), pp.
Bhausaheb L. Pangarkar, Mukund G. Sane, and Mahendra Guddad, (2011). Reverse Osmosis and Membrane Distillation for Desalination of Groundwater: A Review. . 2011 (), pp.
Khamis (e.g. 2011). Nuclear Desalination. [ONLINE] Available at: http://www.world-nuclear.org/info/Non-Power-Nuclear-Applications/Industry/Nuclear-Desalination/#.UT17CY5c_ww. [Last Accessed March 6 2013]
Marek Gryta, (2012). Effectiveness of Water Desalination by Membrane
Distillation Process. membranes.
(), pp.
Xanthe Webb Aintablian (2011). Water Desalination. [ONLINE] Available at: http://geography.about.com/od/waterandice/a/Water-Desalination.htm. [Last Accessed March 2 2013].