Nanotech 'tea bags' for clean drinking water

South African researchers create low-cost, high-tech tea bags that filter water for those living off the water grid.
Written by Melissa Mahony, Contributor on

Over the last few years, portable, purifying devices have been arising to bring clean drinking water to places where it's hard to come by. There's the LifeStraw, a ceramic pot, the LIFESAVER bottle, the Slingshot and others.

Now there's a tea bag.

South African researchers at Stellenbosch Universityhave created a tea bagthat fits into the neck of a special water bottle to filtrate bacteria and microbes from the water within the bottle.

Tea bag is a bit of a misnomer. The material is the same used for say a rooibos tea bag, but instead of dried leaves, the biodegradable bag holds activated carbon. Lining the bag is also a thin antimicrobial film encapsulated within nanofibers.

Nor is brewing necessary. According to its developers, like other filters the bag purifies the water as it passes through the bottleneck to the awaiting mouth.

SciDev.net quotes microbiologist Marelize Botes:

What is new about this idea is the combination of inexpensive raw materials, namely activated carbon and antimicrobial nanofibres, in point-of-use water filter systems.

The nanofibres will disintegrate in liquids after a few days and will have no environmental impact. The raw materials of the tea-bag filter are not toxic to humans.

After testing the filtration system on heavily polluted water and on a river nearby the university, the researchers recently patented the filter bags, though they are not yet ready for commercial production.

Working at just a liter at a time, the single-use bags will likely not solve the developing world's drinking water problems. Even at less than a penny, the filters could still be a little pricey for the people that need them for their daily drink. But they might very well help some, and being lightweight and small, I'd pack a few for a hiking trip.

Below the inventor Eugene Cloate takes a swig from a river after Botes describes how they produce the anti-microbial nanofibers.

Related on SmartPlanet:

Via: Good
Image: Jacque Botha

This post was originally published on Smartplanet.com

Editorial standards