High school students in Maryland have developed a very inexpensive device to filter lead from water. As well as being less expensive than conventional systems, the filter has a built-in warning system that lets users know when it needs to be changed.
Worldwide, there are still millions of homes that continue to receive water from lead pipes. Lead could leach into drinking water.
Lead is toxic and its consumption can cause heart, kidney and reproductive problems in adults. Children, on the other hand, can suffer from lower IQs, behavioral problems, and slower growth, among other things, if even low levels of lead reach their bloodstream.
While these pipes are being replaced, people can use filtration systems to remove lead from their water, but these filters can be bulky and expensive, and it can be very difficult to tell if they are working properly.
A few years ago I saw a video of a Michigan woman turning on her water faucet and she came out brown.
This got me thinking: since there is no safe level of lead in drinking water, wouldn’t it be nice to have a water filter that would tell you that your water is contaminated, long before that it does not turn brown because of the lead?
Rebecca Bushway, teacher at Barrie Middle and High School.
Bushway brought up the problem of lead in water with his chemistry students, and they quickly began brainstorming ideas for a low-cost water filter.
They used biodegradable plastic to 3D print a prototype device that would attach directly to a household faucet. They added powdered calcium phosphate and potassium iodide inside the device.
Calcium phosphate first binds to dissolved lead in water to form free lead calcium phosphate. Calcium, which is harmless, ends up in the water and lead phosphate remains in the filter.
When the calcium phosphate can no longer remove the lead from the water, the potassium iodide powder at the bottom of the device reacts with the lead. This gives a yellow tint to the water coming out of the filter: this is the signal for users that it is time to replace the device.
It took more than a dozen failed prototypes to get everything perfect, but now the students have a working water filter that Bushway presented at the American Chemical Society’s spring meeting.
During the presentation, he noted that the team hopes to find partners to help manufacture and distribute the device, which he hopes can be sold for as little as $1.
More information: www.eurekalert.org (English text).