How to make fresh water from sea water. How to make drinking water from sea water on a desert island

Water is vital for every person on the planet. Unfortunately, it is not available to everyone. But a new invention developed by a research group 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 coarse salt particles and impurities. The remaining salt is heated, evaporated, and then condenses back into pure water.

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

In addition, the researchers discovered another interesting feature of this technique. It is able not only to filter out salts, but to remove other pollutants.

Efficiency

According to Helmi El-Zanfali, a professor at the National 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 and 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.

At the moment, the technology is not yet ready for domestic use. The development has been proven in theory to be effective, but large-scale demonstrations and action plans have yet to be made to deal with the waste.

WikiHow is a wiki, which means that many of our articles are written by multiple authors. When creating this article, 13 people worked on editing and improving it, including anonymously.

Over 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, with much of it entering the Gulf countries as drinking water. It is 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. Currently, there are several methods used to desalinate water in large quantities, including direct osmosis, carbon nanotubes, and biomimetics. However, evaporation is still the most common way to obtain desalinated water. All desalination methods produce hazardous by-products, such as concentrated brine, which pose an environmental hazard to fresh water and animals. Perhaps you want to know how water is desalinated on a small scale for a variety of reasons, such as the desire to teach students if you are a teacher, or to quench your thirst if you suddenly get lost at sea. One method of desalination (using the Sun) is evaporation. The method is quite simple and can be performed in various ways, which are discussed below.

Life can bring many surprises. And not always pleasant. We hope you don't find yourself stranded on a deserted island or in the middle of the African desert with no access to drinking water. But, nevertheless, we advise you to learn how to desalinate sea water using improvised means. Would it come in handy?

The method described below is very popular among fans of life hacks for survival. And for good reason: the process is simple, it does not require much “inventory” and relatively little time. If you start the distillation process at dawn, by noon the sea water will be drinkable.

To desalinate sea water and make it drinkable, you will need:

1. Bucket, bowl or saucepan;
2. Dark container (black color more effectively attracts solar heat and heats up);
3. A glass or a plastic bottle without a throat;
4. Film, plastic bag or cap;
5. Sunshine

Step 1

Place a dark container in a large bowl or bucket.

Step 2

Place a glass or plastic bottle with a cut neck in the middle of the structure.

Step 3

Fill the black container with sea water. Make sure it doesn't hit the glass in the middle.

Step 4

Cover the entire structure with a film or a tight lid. Tightness is everything. If you are using a film, in the center, directly above the glass for desalinated water, put a stone or other weight.

Step 5

Leave your distillation apparatus in the sun and wait. For 8-10 hours under the film in conditions of artificial “heat”, sea water will evaporate, turn into condensate and fall directly into a glass in the form of fresh “precipitation”.

Getting drinking water on a desert island is not easy, but it is quite feasible

If you were on desert island, then with some wit and a container made from leaves or sunken fruits, you have a good chance get fresh water and stay alive for many days. To turn salt water into drinking or fresh water, you need to rely on the principles of nature. During the evaporation of sea water, pure water is collected, and salt remains. The following process is based on the solar desalination method to collect water for drinking in an emergency.

Instructions on how to get drinking water

1. Dig a hole to collect water. The hole should be at least 1 meter deep and wide enough for you to reach the bottom with your hand. As soon as you get close to 1 meter, you should see very wet sand or a puddle of water. Take your time, as you are limited in water, and the tension will cause thirst ahead of time.

2.Place the container in the center of the hole. The container can be a hollowed out coconut, fruits or large leaves. If there is enough vegetation on the island, then you can add it to the hole around the tank. The water from the vegetation will evaporate and accumulate in the vessel.

3. Cover the hole and bend the cover. Place a large leaf (for example, from a palm tree) on the hole and cover it as completely as possible. Secure the outer edges of the sheet with stones. Place a few pebbles in the center of the lid to create a small indentation above the bowl. This will direct the water into the vessel. During the day and night, dew and condensate will collect on the makeshift cover and drain into the vessel.

4.Periodically remove the container from the pit to drink water or fill other containers for later use. Place the vessel back into the hole to continue accumulating water. The water will be safe to drink. No

People have long figured out how to desalinate sea water in the absence of access to potable water, because drinking moisture is the basis for the existence of a living organism.

Today, you can get desalinated water from sea water in different ways and under different conditions - industrial, domestic and even extreme. Such skills will quench the pangs of thirst when fresh drinking water is out of reach for some reason.

Existing water desalination methods

In some regions of the planet, the shortage of fresh water is most noticeable - usually these are arid landscapes. In such an area, industrial desalination is used.

At home, the production of desalinated water from salt water is forced by difficult living conditions, temporary or permanent, when the population is experiencing an acute shortage of drinkable moisture.

Skills on how to make drinking water, having only sea water, more than once saved lives in conditions of natural disasters, for fishermen lost in the sea, as well as for extreme travelers.

Methods of industrial desalination - chemical with the help of reagents, industrial distillation in a distiller, ionic with the help of a plant and an ion exchanger, reverse osmosis through membrane filters, electrodialysis and industrial freezing;
Home desalination methods - distillation and partial freezing;
Extreme desalination methods - collection of condensate using fire or sun, as well as melting fresh ice.

Methods for desalination on an industrial scale are not our topic, but we will describe in more detail how to get moisture quite suitable for drinking at home or in nature - they can be useful.

Water desalination at home

At home there is always a source of fire or heat, utensils and appliances that will be useful for turning sea water into desalted distillate, in extreme cases there is a freezer.

Best of all, it distills sea water into a distillate of a household moonshine if there is a source of fire, but its counterpart, made in haste, will also work. The task is this:

cause sea water to evaporate abundantly from heating;
drain the collected condensate;
cooling drops of steam, collect them in a separate container.

As a substitute for moonshine serpentine, any dishes that can be put on fire are suitable. Sea liquid is poured into it, then the vessel is covered with a lid with a hole into which a steam-removing tube is inserted. It remains to put a plastic hose on the tube, lower its tip into the container where fresh water will accumulate, and cover it with a wet rag so that the steam cools faster.

Sometimes during a disaster in the surviving housing there is no water, no gas, no electricity, but there is some kind of undrinkable water. In this case, there are 2 options not to die of thirst.

Option number 1.

The initial liquid is poured into a plastic bottle.
Its level should be such that it does not reach the neck of the bottle if it is laid flat.
The neck of the bottle with the original liquid is connected to the neck of the empty bottle with adhesive tape.
The design is placed flat in the warmest place that is found in the house - for example, a battery or a sun-drenched window sill.
Any object is placed under an empty bottle so that it is slightly higher than a bottle of liquid.
Soon, drops of evaporated condensate will accumulate at the top of the empty bottle and flow down.
It remains to cut the adhesive tape and separate the containers - the empty water will be drinkable.

Option number 2.

We need a small basin with high walls.
A small container is placed in the center (a simple glass will do).
Water for desalination is poured into the basin, its level should be below the level of the glass.
Polyethylene or cellophane film is stretched on top of the pelvis.
A small weight is placed on the film, directly above the glass.
The design moves closer to the heat source.
Soon, drops of evaporated condensate will accumulate on the film and flow down.

It remains to remove the cellophane from the basin - the glass will contain drinkable water.

Note! These methods work remarkably well in natural conditions.

The third option to get drinking water is partial freezing in the freezer.

Pour sea water into a wide container.
Place in the freezer.
Periodically monitor the freezing process.
As soon as a thin layer of ice appears, carefully collect it, this will be fresh water.
Remove each time only a small layer of ice - its crystals contain almost no salt.

Note! Completely frozen sea water will produce salty ice.

Water desalination under extreme conditions

To get hold of drinking water, having an abundance of sea water, in an extreme environment, when kilometers to a natural fresh water source, is a matter of survival.

The fastest option is to build a primitive distiller on the fire.

To do this, a container filled with sea water is placed on the fire and covered with a lid on top.
It is advisable to make a hole in the lid and insert a steam outlet tube into it.
If there is no hole and there is nothing to pierce it with, then the tube is simply clamped with a lid.
The other end of the tube, through which drops of condensate will flow, must be lowered into a clean bowl.
To speed up the escape of steam, the tube is covered with a wet cloth or constantly poured with cold sea water.
In the absence of a lid, a “roof” is constructed from the dishes at an angle of metal, a clean vessel is substituted to the lowest edge, where the distillate will drain.

If it happens in the summer heat, there is a very simple option to desalinate the water, but in time it will not be as fast as with the help of fire. To do this, you need only one container, a film and a dug hole.

You need to dig a hole a little deeper than the height of your container.
The bottom of the pit is abundantly watered with sea water.
An empty container is placed in the center of the recess.
The pit is completely covered with a film, and its edges are tightly fixed with sand, pebbles, earth.
A load is placed on the center of the film, directly above the vessel - a pebble, a stick, a lump of soil or a handful of sand, so that the coating becomes concave.
Water, evaporating, will begin to settle on the roof of the film and flow down the slope straight into the placed container.
In the heat, in a couple of hours, enough water will collect in the vessel to get drunk.

Note! The condensate is completely devoid of salts, so in order to quickly quench your thirst, experienced thrill-seekers advise adding a little sea water.

Another method of desalination is freezing, suitable for harsh winter conditions. Its algorithm is similar to home freezing, only street frost will act as a freezer here. You need to scoop up sea water and wait for ice crystals to appear on the surface - they will taste fresh, and you can drink such water.