Dartmouth Engineer

GETTING THE ARSENIC OUT: Left to right, Lindsay Holiday, Dana Leland, and Philip Wagner present their arsenic removal system during an ENGS 290 class. Photograph by Douglas Fraser.

Three recent graduates came up as winners in the National Inventors Hall of Fame’s 2009 Collegiate Inventors Competition for a simple, inexpensive method they developed to remove arsenic from drinking water.

As students in Thayer School’s capstone course ENGS 190/290: Project Design, Lindsay Holiday ’07 Th’09, Dana Leland ’09, and Philip Wagner ’09 invented the system for use in rural Nepal, where arsenic, which occurs naturally in rock formations, is a major groundwater contaminant.

The device employs the same process — electrocoagulation — that is commonly used in large-scale water treatment facilities but in a scaled-down version that can be made from locally available materials: three buckets, sand, a 6-volt battery, and two steel plates. Contaminated water is poured into one bucket, and an electrical current is sent through submerged steel plates to release iron precipitates. After the iron particles bind to the arsenic, the water is poured into a second bucket of sand. The sand filters out the iron-arsenic particles, and the clean water flows out a hole into the empty third bucket. The unit can purify 15-liter batches of water. When the students tested the process, they started with water containing arsenic levels of 200 ppb. When they were done, the treated water contained less than 1 ppb, well below the World Health Organization’s 10 ppb standard.

Calling the worldwide need for this system “immense,” the project’s sponsor, David Sowerwine of VillageTech Solutions (VTS), says, “We are really pleased with the work of the design team from Thayer.” Now VTS aims to raise enough funds to put a design and business team on the ground in Nepal, India, or Bangladesh. The goal: complete a manufacturable product, business plan, and donor-support agreement within 24 months.

“I hope that our work can help bring clean drinking water to people in need,” says team member Leland.

The student trio also received Thayer School’s 2009 Special Faculty Award for Engineering and Service to Humanity.

— Kathryn LoConte

For more photos visit our Student Projects set on Flickr.

BIG WHEELS: Left to right, Deborah Sperling’06 Th’07, Hannah Murnen ’06 Th’07, Nathan Sigworth ’07, and Augusta Niles ’07 model the Gyrobike for Popular Mechanics. Photograph by Chad Hunt, courtesy of Popular Mechanics.

How far can a gyrobike go? All the way to Popular Mechanics magazine’s 2006 Breakthrough Awards. “One of my favorite inventions this year is the Gyrobike, created by a group of Dartmouth students. It’s an elegant, simple solution to the eternal problem of learning to ride a bike,” writes Jim Meigs, the Popular Mechanics contributing editor who oversaw the awards project. “People have been perfecting bikes for over 100 years, and there’s been a knowledge of gyroscopes for much longer, but these students were the first to combine them in a device like this. And they did the work in an introductory engineering course, which shows that you don’t have to be an expert with an advanced degree to invent something important — you just need creativity and resourcefulness.”

The editors of Popular Mechanics aren’t the only people who like the Gyrobike. Kids who’ve never ridden a two-wheeler love it because they can hop on and ride it right away.

Gyrobike inventors Hannah Murnen ’06 Th’07, Augusta Niles ’07, Nathan Sigworth ’07, and Deborah Sperling ’06 Th’07, who created the bike for their ENGS 21 class in 2004, are working to bring it to market.