A tea bag-sized filter that cleans highly polluted water and costs about three cents a litre to use could be available to the public in approximately six weeks, the University of Stellenbosch said.
"The water is cleaned right then and there when you drink from the bottle," said professor Eugene Cloete, the dean of the faculty of science at the University of Stellenbosch (US), in a statement.
Cloete said the filter could help meet the needs of people who lived in remote areas or whose regular water supply was not being treated to potable standards.
"The lack of availability of adequate, safe and affordable water supplies impacts severely on vulnerable groups such as the poor, the elderly, HIV/Aids patients and children," he said.
Tea-bag filters will decrease spread of cholera
"More than 90 percent of all cholera cases are reported in Africa, and 300 million people on our continent do not have access to safe drinking water. Clearly, something has to be done about this," he said.
A researcher on the project, Marelize Botes, said the filters would cost only three cents and fitted into the neck of a bottle.
She said the filters were disposable, portable, easy to use and environmentally friendly.
The filters were made with the same materials as rooibos tea bags.
Filters kill the disease-causing microbes
Cloete, a past executive vice-president of the International Water Association and a member of Coca-Cola's world-wide panel of water experts, worked on the invention with researchers from the Department of Microbiology and other US scientists for 18 months and patented it in January.
“The inside of the outer material is coated with a thin film of biocides, encapsulated within tiny nanofibres, which kills all disease-causing microbes,” said Cloete.
“The bag is filled with active carbon granules that remove all harmful chemicals.”
The filters were tested in a very polluted river in Stellenbosch where they proved to clean one litre of the most polluted water to the point where it was 100 percent safe to drink.
The invention was submitted for testing by the South African Bureau of Standards, after which the team hoped to introduce it to various communities, as well as the outdoor activities market. (Sapa, August 2010)