Its been long understood that the world is headed towards a profound water crisis as stocks of drinkable water become harder to find and keep free of contaminants. Filtration systems like those you may have at home which use carbon are possible, but quite expensive to produce. Sand has long been used as another method of purification, but does not do as well in cleaning water fully of all contaminants and heavy metals. Recently Rice University researchers showed off their innovation that uses nano-technology to put a graphite coating on grains of sand, thus making it a far more effective purification medium.
Graduate student Wei Gao demonstrates this “magic sand” in this video link.
For more information see this link.