Stellenbosch University's Hope Project has produced a disposable water filter shaped like a tea bag. When placed in the neck of a water bottle, the bag removes all harmful chemicals and microbes. Each bag cleans one liter (1.06 quarts) of water, so a lot will be needed to make any significant impact on water-related health issues globally. However, when compared to competition such as the LifeStraw or LifeSaver, it would seem to be a cost effective solution. The product is currently being tested by the South Africa Bureau of Standards.

Nanofibers on the inside of the bag contain biocides, which kill all the microbes in the water. Chemicals are removed by the active carbon that replaces the tea in the bag. Whilst the images and video on the project's website show what looks to be a specially produced water bottle being used with the bag, it would appear from the BBC News website that an alternative arrangement exists involving the modification of a regular water bottle lid. Presumably the bag functions properly as long as it fits snugly in the mouth of the bottle, in such a way that all water must pass through it.

The project, at the university's Water Institute, is headed by previous executive vice-president of the International Water Association and member of Coca Cola's worldwide panel of water experts Professor Eugene Cloete. He obviously believes in the technology, as he can be seen using it to drink from a creek in the video below.

“We tested the filter with water taken from a river here in the Stellenbosch area. The samples were highly polluted with pathogens, but they came out completely clean on the other side,” said Dr Michéle de Kwaadsteniet.

If the South Africa Bureau of Standards give this the green light, it will no doubt be of great benefit to those without access to clean drinking water worldwide.

All images copyright The Hope Project