One of the biggest problems of today - all the small amount of water - could be solved by using sand.
Sand is cheap and it can filter the water of different particles.
However, as an ordinary sand is not effective in removing heavy metals and toxins, scientists have found a way to improve it.
Scientists at Rice University in Houston made a "covered with sand" that uses graphite oxide (a substance used in making graphite pencils) is removed from the water all that sand can not be ordinary.
This "super sand" is just as effective as filtering devices for water, but it is much cheaper than them.
Graphite oxide is mixed with sand so that I distribute coats the grains of sand and easy to remove dissolved contaminants from water.