Ordinary sand can be transformed into a “super sand” with five times the filtering capacity of regular sand, for improved purification of drinking water. Researchers coated sand grains with a nanomaterial called graphite oxide (GO), and found that it could be used to improve sand filtration in a cost-effective way. The World Health Organization endorses sand or gravel water filtration as a way to purify drinking water. The new material could be a low-cost boon for developing countries, where more than a billion people lack access to clean drinking water. Tests showed that the super sand was able to successfully remove mercury and a dye molecule from water. According to Mainak Majumder and colleagues, the super sand’s filtration “performance is comparable to some commercially available activated carbon. We are currently investigating strategies that will enable us to assemble functionalized GO particles on the sand grains to further enhance contaminant removal efficiencies.” The scientists’ work has been published in the journal ACS Applied Materials & Interfaces.