Rust constituent could help remove arsenic from drinking water

Researchers at Rice University have discovered that one of the constituents of rust could help to remove arsenic from wells in Bangladesh.
The arsenic was coming from wells in the Ganges River basin and threatening people who drank the tainted water with various ailments, including death. Reports in Scientific American’s online newsletter and Science magazine, said that researchers at Rice University’s Center for Biological and Environmental Nanotechnology have developed a small-scale, cheap and energy-free process to clean the well water.
The method follows the discovery of unexpected magnetic interactions between ultra-small specks of rust, taking advantage of nanoparticles of magnetite, an iron oxide. The university researchers discovered they cold move the nanoparticles from the water with handheld magnets. Using magnetite particles just 12 nanometres wide — smaller than a virus — they cleaned a 2-litre arsenic solution that had 50 times the arsenic allowed in drinking water to almost the levels dictated by the U.S. Environmental Protection Agency.
The lead physicist at Rice, Doug Natelson, explained that the nanoparticles exerted forces on each other, they essentially clumped together, making it easier to remove them.
Following the small-scale test, the researchers are hoping to apply the method to a larger scale batch, such as the size of a water cooler.
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