Graphite oxide improves sand filtration fivefold, say researchers

In a discovery which could have implications for desalination pretreatment, a research team divided between Rice University, USA, and Monash University, Australia, has found a way of transforming sand with nanotechnology to make it five better at filtering water.

In a paper Engineered Graphite Oxide Materials for Application in Water Purification in the American Chemical Society journal Applied Materials & Interfaces, Mainak Majumder and his colleagues say their studies of the nanomaterial graphite oxide (GO) suggest that it could be used to improve sand filtration in a cost-effective way.

"Core-shell" adsorbent granules, readily useable in filtration columns, are synthesized by assembling aqueous GO over sand granules. The nanostructured GO-coated sand retains at least fivefold higher concentration of heavy metal and organic dye than pure sand.

In the mercury test, ordinary sand was saturated within 10 minutes of filtration, while the 'super sand' absorbed the heavy metal for more than 50 minutes, the scientists discovered. Its filtration "performance is comparable to some commercially available activated carbon," the scientists said.

"We are currently investigating strategies that will enable us to assemble functionalized GO particles on the sand grains to further enhance contaminant removal efficiencies," they write.

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| Nanotechnology


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