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Desalinization
Three quarters of the earth is covered with water, but you can’t drink it. Turning salt water into fresh water for drinking and for watering crops is vital for the future of the human race. Questions about desalinization (or desalination) are answered here.
245 Questions
Why isn't desalination used more?
Desalination isn't used more often because it cause's a waste stream called brine and the discharge of chemicals and all that waste can affect the marine life
To remove salt from drinking water. Drinking saline water causes mental problems and can lead to death. The body can only handle certain quantities of salt - to much causes imbalances that, as mentioned above, can cause serious health problems.
How do you get desalination job?
To secure a job in desalination, start by obtaining a relevant degree in engineering, environmental science, or a related field. Gain experience through internships or entry-level positions in water treatment or environmental projects, and consider specialized training in desalination technologies. Networking with professionals in the industry and staying informed about advancements can also enhance your opportunities. Finally, actively search for job openings in companies or organizations focused on water resources and desalination.
Why would countries use the desalination process?
Desalination is a process that removes mineralsfrom saline water. More generally, desalination may also refer to the removal of salts and minerals,[1]as in soil desalination, which also happens to be a major issue for agricultural production.[2]
Salt water is desalinated to produce fresh water suitable for human consumption or irrigation. One potential by-product of desalination is salt. Desalination is used on many seagoing ships and submarines. Most of the modern interest in desalination is focused on developing cost-effective ways of providing fresh water for human use. Along with recycled wastewater, this is one of the few rainfall-independent water sources.[3]
Due to relatively high energy consumption, the costs of desalinating sea water are generally higher than the alternatives (fresh water from rivers or groundwater, water recycling and water conservation), but alternatives are not always available and rapid overdraw and depletion of reserves is a critical problem worldwide. Quoting Christopher Gasson of Global Water Intelligence, "At the moment, around 1% of the world's population are dependent on desalinated water to meet their daily needs, but by 2025, the UN expects 14% of the world's population to be encountering water scarcity. Unless people get radically better at water conservation, the desalination industry has a very strong future indeed."[4]
Desalination is particularly relevant in dry countries such as Australia, which traditionally have relied on collecting rainfall behind dams to provide their drinking water supplies. According to the International Desalination Association, in June 2011, 15,988 desalination plants operated worldwide, producing 66.5 million cubic meters per day, providing water for 300 million people.[5]This number has been updated to 78.4 million cubic meters by 2013,[4]or 57% greater than just 5 years prior. The single largest desalination project is Ras Al-Khair in Saudi Arabia, which produced 1,025,000 cubic meters per day in 2014,[4]although this plant in Saudi Arabia is expected to be surpassed by a desal plant in California.[6]The largest percent of desalinated water used in any country is in Israel, which produces 40% of its domestic water use from seawater desalination.[7]
Where does the salt initially go in a desalination plant and how is it removed from the desalinator?
Salt water is pumped through a very fine membrane which does not allow the salt to pass through (osmosis). Only part of the water is "desalinated". The rest, with all the salt, is usually pumped back into the ocean, at some distance away from the plant.
What science is behind working in a desalination plant?
Evaporation and condensation of water - that is the basic one... Others could use reverse osmosis, which is far more effective, but very expensive...
Why should the desalination plant be built?
Because only three percent of the world's water is potable. And with man-made pollution that number is going down.
What id the meaning of recovery ratio in RO desalination plant?
It is the ratio of permeate over the feed water.
Opposition to the construction of desalination plants often stems from environmental concerns, such as potential harm to marine ecosystems due to the intake of seawater and the discharge of brine. Critics also argue that desalination is energy-intensive, contributing to carbon emissions and climate change. Additionally, some community members fear the potential for increased water rates and the prioritization of large-scale projects over more sustainable water conservation methods. Lastly, there may be concerns about the impact on local economies and water equity for marginalized groups.
What is mean by desalination of brackish water?
Brackish means slightly salty. Desalination is the process of removing the salt.
How are desalination and the water cycle similar?
they are, but they are not.
The water cycle has water (Lake or ocean, fresh or salt) that evaporates (leaving any salt behind) to become clouds, which rains fresh water that runs back to the sea.
Desalination is a process that uses various methods to remove the salt from sea water to make it drinkable.
Distillation is the only form of desalination that comes anywhere close to the water cycle, since it involves changing the state of the alter from liquid to gas and back again. Other desalination processes do not change the state of the liquid, but filter it remove the salt and make it potable and same for human consumption.
Desalination is expensive because it requires what?
Desalination requires a lot of of energy or electricity, which makes it expensive.
Are desalinization and desalination interchangeable words?
Yes. Desalinization is a redundant and incorrect form, so desalination only should be used.
The positive and the negative things about the desalination plant?
well the negative things are:
- fish and other animals could get stuck in the pipes.
- most animals in the ocean would die, because of less water.
-we don't no if the water would taste the same.
the positive things are:
-more water for australians
and that's it.
Desalination is expensive because it requires?
It is expensive because if requires a great deal of energy or electricity.
How do you use desalination in a sentence?
Desalination is the removal of salts from solutions in water. There are many ways to use it. An example is: "The ocean water was sanitized and purified by desalination, boiling, and filtration to prepare it for drinking."
Water desalination is the process of removing salt and minerals from seawater to make it suitable for drinking or irrigation. This is typically done through methods such as reverse osmosis or distillation to separate the salt from the water, producing freshwater for consumption. Desalination is an important technology in areas where freshwater resources are limited.
Advantages and disadvantages of desalination plants?
Advantages Disadvantages *It can work as a backup incase the dams run out of water or are low and if there is a drought *It cost to much money to pay for the plants *The ocean is always there and easy to get to *It reduces oxygen levels in the air and results in an increase of the density of any discharged waste water. *Its unlimited source of water. *make more green house gasses so there for more pollution in the atmosphere *It doubles the amount of salt in the ocean's and impacts on the environment for animals and humans.
it allows you to use all the water in the world, the price has been going down
Why is desalination expensive?
Desalination is primarily accomplished through reverse osmosis (forcing water molecules through a semi-permeable membrane) or distillation (evaporating salt water and then condensing the vapor). Both processes require large energy inputs to accomplish.
Carbon footprints will be increased by 180 kgs per 60, 000 of water, and that equates to a full tank of gasoline; however, that is less than traveling from Perth to Sydney!
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On the other foot, the construction costs are very large, the running costs are big and ongoing, and there is still resistance from the neighbors on the impact on the local community from construction and also from having a large, noisy, 24/7, industrial-size building stuck on your local beach between the houses bought for the ocean view and the ocean.
Where is the largest desalination plant in the southern hemisphere located?
Its 59 miles ouside Melbourne in the state of Victoria.
How is desalination of water done?
Multi-stage flash distillation
Multi-stage flash distillation (MSF) is a desalination process that distills sea water by flashing a portion of the water into steam in multiple stages of what are essentially regenerative heat exchangers. First, the seawater is heated in a container known as a brine heater. This is usually achieved by condensing steam on a bank of tubes carrying sea water through the brine heater. Heated water is passed to another container known as a "stage", where the surrounding pressure is lower than that in the brine heater. It is the sudden introduction of this water into a lower pressure "stage" that causes it to boil so rapidly as to flash into steam. As a rule, only a small percentage of this water is converted into steam. Consequently, it is normally the case that the remaining water will be sent through a series of additional stages, each possessing a lower ambient pressure than the previous "stage." As steam is generated, it is condensed on tubes of heat exchangers that run through each stage.
Reverse osmosis
Reverse osmosis is a filtration process typically used for water. It works by using pressure to force a solution through a membrane, retaining the solute on one side and allowing the pure solvent to pass to the other side. This is the reverse of the normal osmosis process, which is the natural movement of solvent from an area of low solute concentration, through a membrane, to an area of high solute concentration when no external pressure is applied. The membranes used for reverse osmosis have a dense barrier layer in the polymer matrix where most separation occurs. In most cases the membrane is designed to allow only water to pass through this dense layer while preventing the passage of solutes (such as salt ions). This process requires that a high pressure be exerted on the high concentration side of the membrane, usually 2-17 bar (30-250 psi) for fresh and brackish water, and 40-70 bar (600-1000 psi) for seawater, which has around 24 bar (350 psi) natural osmotic pressure which must be overcome.
Normally in osmosis when two solutions with different concentrations of a solute are mixed, the total amount of solutes in the two solutions will be equally distributed in the total amount of solvent from the two solutions. Instead of mixing the two solutions together, they can be put in two compartments where they are separated from each other by a semipermeable membrane. The semipermeable membrane does not allow the solutes to move from one compartment to the other, but allows the solvent to move. Since equilibrium cannot be achieved by the movement of solutes from the compartment with high solute concentration to the one with low solute concentration, it is instead achieved by the movement of the solvent from areas of low solute concentration to areas of high solute concentration. When the solvent moves away from low concentration areas, it causes these areas to become more concentrated. On the other side, when the solvent moves into areas of high concentration, solute concentration will decrease. This process is termed osmosis. The tendency for solvent to flow through the membrane can be expressed as "osmotic pressure", since it is analogous to flow caused by a pressure differential.
In reverse osmosis, in a similar setup as that in osmosis, pressure is applied to the compartment with high concentration. In this case, there are two forces influencing the movement of water: the pressure caused by the difference in solute concentration between the two compartments (the osmotic pressure) and the externally applied pressure.
Comparison between the two
The more efficient method is multi-stage flash distillation and hence currently produces the world's largest quantity of desalinated water. However, MSF requires a large system and works mainly in industrial production, hence reverse osmosis is more appropriately used in homes as a smaller household system despite its lower efficiency, due to its far quieter operation and smaller mechanism.
What countries use desalination plants?
Perth and Melbourne use it in Australia because they are near the sea, Israel, Saudi Arabia, and several Persian Gulf countries use desalination plants as well given the amount of desert they contain.
Desalination has very high energy requirements and since most countries with desalination plants do not have nuclear power, it results in the burning of lots of more coal. Additionally, the methods by which salt is removed from water create a resulting "salt-slurry" which is ejected as waste in to the original saltwater body. This salt-slurry makes the area around the desalination plant poisonous for the local sea-life.
However, in almost every case, the positives of desalination outweigh these negatives.
