We live in a unique place - the Earth, which, although it has a lot of land, is still mostly covered with water. We swim in it, move through it and, most importantly, drink from it. Unlike many animals, we are unable to get enough fluids simply from fruits and vegetables - we need to drink fluids regularly to stay hydrated. But only the water space has one more unique property– it’s almost all salty. The percentage of fresh water is surprisingly small. Yes, we are accustomed to it, because this kind of water comes into our homes and is sold in stores. But what if we suddenly don’t have access to fresh water, if we only have sea water? Then it needs to be desalinated. Let's figure out how this can be achieved.

You will need:

This method is also called sublimation. It can be easily implemented even in living conditions, Although large quantity he will not provide liquids.

Take an ordinary saucepan into which salted water is poured. Next, you need to cover this pan with a lid and put it on fire. Gradually, condensation will accumulate on its lid.

However, even when removing the lid, most of the unleavened drops will flow back into the pan, so it is necessary to slightly improve this improvised device.

• A hole is drilled in the lid of the pan.
• A flexible tube is inserted into it, for example, a coil from a moonshine still.
• Its other end is lowered into an empty vessel.
• Next, you need to cover the tube with a damp cloth so that the steam in it cools.
• It will condense and fall into the empty vessel.

As a result, the heated pan will end up with only salt, and the second vessel will only have distilled water.

Keep in mind, however, that there will be no salt in such a liquid at all, and therefore your thirst will be poorly quenched.

It is better to pour a small amount of salt water into it.

This method uses special precipitating reagents. They interact with salts contained in sea water and form compounds that are not soluble. Therefore, they settle and can be filtered out calmly and without problems.

This approach has its disadvantages, in particular, the high cost of reagents, the slowness of the reaction, and the large number of necessary reagents.

This method is predominantly industrial and has been used for a long time. It is based on the use of two semi-permeable membranes made of cellulose acetate or polyamide. Small water molecules can penetrate through them without any restrictions, while larger ions of salt, as well as other impurities, are retained and are not allowed further.


It is difficult to achieve desalination of a large amount of liquid in this way, and this method is difficult to implement in everyday life - it is suitable for industrial enterprises.

This desalination method seems very simple in its idea, but in its implementation it is quite labor- and resource-intensive. The idea is based on the fact that salt does not get into the ice during freezing, because ice formation occurs only from water molecules.

The largest amount of fresh water in nature is contained in all kinds of glaciers.

Usually the Eskimos resort to this method. They expose a container of salt water to the cold, and then wait until ice crystals form there. This ice is collected and melted - and the water can be drunk.

WikiHow works like a wiki, which means that many of our articles are written by multiple authors. This article was produced by 13 people, including anonymously, to edit and improve it.

More than 97.5% of the water on Earth contains salt, and desalination is the process of removing salt from water. More than 60 billion liters of desalinated water are produced daily, most of it in the form of drinking water to the Gulf countries. It's a challenge for engineers around the world to find a desalination method that is cheap enough to bring desalinated water to poor and remote areas of the Earth. There are currently several methods used to desalinate water in large quantities, including forward osmosis, carbon nanotubes and biomimetics. However, evaporation is still the most common method of producing desalinated water. All desalination methods produce hazardous byproducts, such as concentrated brine, which poses an environmental hazard to fresh water and animals. You might want to know how water is desalinated on a small scale for a variety of reasons, such as teaching students if you're a teacher, or to quench your thirst if you find yourself lost at sea. One method of desalination (with the help of the Sun) is evaporation. The method is not at all complicated and can be performed in various ways, which are discussed below.

Once again to the question of obtaining suitable drinking water in extreme conditions.

What to do on a hike when drinking water is not provided along the way? For example, there will be swamps, lakes, rivers, estuaries, seas. But there will be no clean and fresh water.

Usually, when going on a hike, they take special water disinfection tablets with them; they remember their grandmother’s recipes about disinfecting water with herbs, disinfecting water with peroxide or potassium permanganate.

This is all well suited for fresh and relatively clear water. This, in principle, you can simply boil for about twenty minutes and cook with it calmly.

But what to do if the hike involves meeting only salt water? For example, the southern coast of Crimea and the Kerch Peninsula, where there is a lot to see, have very few sources of fresh water.

You can, of course, buy fresh water. But in such places it is quite expensive. What if the day is arranged far from civilization?

It turns out that there is only one way out - to carry water with you. And it’s somewhat inconvenient to add a five-liter bottle of water to a 15-kilogram backpack.

In order to avoid such inconveniences, a desalination experiment was conducted sea ​​water using the distillation process.

What is distillation

Distillation- this is when the water boils, the steam above it collects, cools, and turns back into water in the receiving container.

Why does distillation remove salts from water? Because salts boil at more high temperature than water. Therefore, water evaporates first. No salts. This is what you need to do with sea water.

What happens if the water that is distilled contains substances that boil at a lower temperature? For example, volatile organic matter? They will evaporate first. Therefore, one of the principles of distillation is not to direct the vapor collector directly to the receiving device, but to allow the water to seriously boil.

Another important principle of distillation is good vapor cooling. The performance of the device directly depends on the cooling efficiency. If some of the steam does not cool, but evaporates, then, accordingly, less pure water will be obtained.

So, how we carried out the distillation of sea water in practice.

Distillation of sea water in practice

Venue : beach north of the village of Podmayachnoe near the city of Kerch. It takes at least half an hour to get to the nearest store with water in the heat. Of course, it’s beautiful there - cliffs, layers of fossils, etc. But it's hot.

Water source: Sea of ​​Azov. The sea is not very salty, salinity is about 10 grams per liter. In comparison, the salinity of the Black Sea is 16-20 grams per liter.

Materials and equipment :

* two bricks;
* bonfire;
* tourist kettle;
* curved aluminum tube;
* glass bottle;
* hole in the sand;
* mug for sea water;
* a lot of wood and a lot of patience

The distillation procedure is very simple. Sea water - into the kettle, kettle - on the fire. Hole in the ground. A glass bottle was buried in it at an angle. Only the neck protruded from the sand, into which the steam transmitting tube was inserted.

That's it - the water boiled, passed through the tube into the bottle, and cooled there. For better cooling, the bottle was watered with cold (relatively, of course) sea water. As the salt water evaporated, it was added to the kettle.

Now the technology know-how:

I. The first thing that was adjusted was the seawater level in the kettle. Sea water should occupy less than half the volume, preferably one third. This is necessary to increase the intensity of vaporization. It is not known why more steam is formed in this case, but it turned out that this is so.

II. Further, the transmission tube must not be watered to cool the steam. The cooling water turned out to be insidious, and flowed down the tube (by the way, about 80 cm long) from below into a bottle with clean water. Accordingly, the taste of the purified water was not very good.

III. Then, it’s better not to take a plastic bottle for the receiving device. Because the steam makes her cringe. Although, if you don’t have a glass one at hand, a plastic one will do. In the area where the camp was located, both plastic and glass bottles were present in abundance.

Results: in 30-40 minutes of distillation, about 350 milliliters of water are purified using the described method.

Conclusions

The tested distiller perfectly purifies sea water. The salts in the resulting water cannot be tasted. Apparently, they simply aren’t there :) The cleaning process requires a fairly large amount of fuel. Thorough cooling of the receiving tank almost doubles the productivity of the distiller. A tested distiller, taking into account all sorts of adjustments and problems per day, can provide clean water to 2-3 people for 2-3 days. In order to provide clean water to a larger number of people for a longer period of time, either a more advanced distiller is needed (which will make its design heavier and make transportation difficult), or the tried-and-tested distiller must be made into personal equipment (every participant purifies the required amount of water per day).

Thus, the studies carried out showed excellent results in purifying sea water using the field method. The most important thing is that the weight of the kettle and steam wand did not exceed 500 grams.

Water- the source of life for all living things, but you need to distinguish which water is healthy and which is not. Approximately 99% of all water on earth is the water of oceans and seas, that is, salt water, unsuitable for consumption. Many people in the world need living, fresh water, and today we will tell you how to get fresh water from salt water.

How to make fresh water from sea water at home?

Fresh water differs from salt water in the amount of salt and other chemical elements. The most popular method is to separate salts from water by distillation.
This method involves heating water to boiling point and collecting the vapors in the form of condensate. This method is well described in the article - .

There is also another method, the so-called desalination. Is that salt water passed through a membrane that is capable of passing only clean water without salt components. But this type purification is not very effective, since the membrane allows a very small amount of water to pass through long period time.

Water is vital for every person on the planet. Unfortunately, it is not available to everyone. But a new invention developed by a research team at the University of Alexandria in Egypt could change that.

Operating principle

The technology uses a desalination technique called pervaporation. Salt is removed from seawater using specially designed synthetic membranes that filter out large salt particles and impurities. The remaining salt is heated, evaporates, and then condenses back into pure water.

In developing countries, investing time and money in developing water filtration technologies is critical. However, the technology must be accessible and easily reproducible. Fortunately, the membranes involved in this new invention can be manufactured in any laboratory. They can be made from inexpensive materials available locally. More importantly, the evaporation process does not require electricity, making this method of drinking water purification cheap and suitable for areas where there is no power supply.

In addition, the researchers discovered another interesting feature of this technique. It is capable of not only filtering salts, but also removing other contaminants.

Efficiency

According to Helmy El-Zanfaly, a professor at the National Scientific Research Center in Egypt, the technology implemented in the study is much better than the reverse osmosis technologies currently used in both Egypt and the Middle East. North Africa. Using this development, it is possible to effectively desalinate water containing high concentrations of salt in the Red Sea, where desalination is more expensive.

On at the moment, the technology is not yet ready for household use. In theory, the development has been proven to be effective, but large-scale demonstrations and an action plan to combat waste have yet to be made.