Purifying drinking water with 'super sand'
Scientists have found a way to engineer sand with five times the filtering capacity of regular sand...
June 23, 2011 -- Using nanotechnology, scientists have found a way to engineer sand with five times the filtering capacity of regular sand.
The researchers from Australia's Monash University, led by Mainak Majumder, say this new 'super sand' could significantly benefit developing countries, where more than a billion people lack clean drinking water.
To make the 'super sand,' researchers coated grains of sand with a nanomaterial called graphite oxide (GO). In lab tests, the 'super sand' was able to remove mercury and a dye molecule from water samples. Ordinary sand, they found, became saturated with 10 minutes of filtration. But the engineered sand continued to absorb the mercury for more than 50 minutes.
The scientists said the super sand's filtration performance was "comparable to some commercially available activated carbon." They said they are continuing to research ways to further enhance the sand to boost its contaminant removal efficiency.