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Dartmouth students design filter to save lives from arsenic poisoning

Print | Comments () Posted by Bennie DiNardo November 2, 2009 01:31 PM

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I’ve written about a naturally occurring arsenic belt in New England that may be putting thousands of families’ private drinking water supplies at risk from central Maine to central Massachusetts.

The Dartmouth students with their household arsenic filter (photo/Douglas Fraser)

But that potential contamination pales compared to arsenic poisoning taking place everyday in Bangladesh, Nepal and other South Asian countries. Every year tens of thousands of people become sickened when arsenic in rock seeps into drinking water supplies. Skin lesions can appear on people and skin and internal cancers can occur.

It’s a global health crisis and now, three Dartmouth undergrad engineering students have come up with an ingenious solution that won $15,000 in the recent 2009 Collegiate Inventors Competition.
Philip Wagner, Lindsay Holiday and Dana Leland built an inexpensive reliable device made of materials locally available in any place suffering from high levels of arsenic in groundwater.

The team uses electrocoagulation, a process used in many modern cities water treatment plants to scrub contaminants from water – but scaled down to fit into three five-gallon buckets. Untreated water is placed in the first bucket and an electrical current powered by a 6-volt battery is sent through two steel plates. Tiny iron particles are released in the process and bond with the arsenic in the water.

The water is then poured into a bucket of clean sand that sits over the third bucket. The sand filters out the iron-arsenic particles and clean drinkable water collects in the bottom bucket. The team tested their device by using water that contained 200 parts per billion of arsenic. By the time it made it to the third bucket, the water contained less than 1 part per billion of arsenic. U.S. EPA officials consider water safe for drinking at 10 parts per billion or less.

The contest is a program of the National Inventors Hall of Fame sponsored by the Abbott Fund, the non-profit foundation of the global health care company Abbott, and the U.S. Patent and Trademark office.

Other students from Harvard Medical School and Massachusetts Institute of Technology also won prizes for medical inventions.