The earth consists of 70 percent water. Of these, the vast majority is salt water, in seas and oceans. Sweet and drinkable water is scarce. There is a large water shortage in some areas. The population continues to grow and the earth is warming up: a gigantic problem. Scientists therefore try to find ways to extract as much water as possible. How do they do that?
Water extraction from mist
In coastal areas they extract water from fog and mist. They use nets that are perpendicular to the wind. The spray droplets are collected by the net. These then fall into containers underneath. Per square meter net, they catch about three liters of water in this way.
Scientists have now improved these mist catchers. At first they were not very efficient, because the holes in the net had to be exactly big enough to catch the water drops. The new system only has vertical wires. The drops fall immediately. This means that nine liters of water can be collected per square meter of net.
Day Zero crisis
The research team hopes to make this system massive and to work together with manufacturers. South Africa is one of the countries where water is badly needed. Here they even speak of the Day Zero crisis.
The mist trap can be made even more efficient, researchers from MIT found. Wind tends to rotate around objects. But because of this, many water droplets are lost in the system. With electrodes, the water can be sent to the wires, instead of around or away from them. The electrodes draw the water droplets to the net, as it were.
If these systems can be used massively, this is good news for dry areas. But in the end, global warming remains a major problem, and it is a matter of time for a large part of the world to have water shortages.