JOHANNESBURG, 19 August 2010 (IRIN) - A cheap and effective filtering device developed by a South African university could provide safe drinking water to millions of people, drastically reducing the incidence of waterborne illnesses such as cholera and other diarrhoeal diseases.

The device resembles a teabag in both size and shape, and was invented by microbiologists, scientists and polymer researchers at the University of Stellenbosch in Western Cape Province. It is being patented and commercial production could start as soon as the end of 2010.

The biodegradable teabag is filled with active carbon granules, while the sachet - made of nano-fibres - is coated on the inside with biocides that kill pathogens, said Marelize Botes, a post-doctoral fellow in the university's Department of Microbiology and a member of the research team.

Botes told IRIN that each teabag could make one litre of dirty water safe, unless it was contaminated by acid mine water - containing high levels of iron, aluminium, and acid - or oil, and it also could not desalinate water.

Nearly half of Africa's about 680 million people do not have access to safe drinking water, which makes them vulnerable to a slew of waterborne ailments.

The simple technology allows for the teabag to be placed in a canister designed to fit the neck of most bottles, and after filtering one litre of contaminated water the teabag is discarded.

Botes said the raw materials for each teabag amounted to less than US$0.005, but the eventual price of a teabag would be determined by taking into account manufacturing and distribution costs.

She said agencies responding to the floods in Pakistan - where, as the poet Samuel Taylor Coleridge noted in the Rime of the Ancient Mariner, there is "Water, water, everywhere, nor any drop to drink" - had already made enquiries about the teabag, but it had not yet reached the manufacturing stage.

The distribution of safe drinking water during humanitarian and natural disasters is vital, but presents a huge logistical challenge because one litre of water weighs one kilogram. The teabag could be used to easily and quickly meet the need for clean water during a crisis.

Safe drinking water is a primary requirement: the body can go for quite long periods without food, and draw on fat reserves, but it has no reservoirs for water and the symptoms of dehydration can set in after the loss of only 2 percent of normal water volume.

In the 2010 Haiti earthquake, water infrastructure was damaged and relief organizations had to dispatch fresh water containers, water purifying tablets and decontamination systems.

"The 'tea bag' filter can show the way forward, as it represents decentralized, point-of-use technology. It can assist in meeting the needs of people who live or travel in remote areas, or people whose regular water supply is not treated to potable standards," Prof Eugene Cloete, a microbiologist and Dean of the Faculty of Science at Stellenbosch University, told local media.

The teabag was invented by the university's Water Institute, an initiative drawing together various disciplines to tackle South Africa's and the continent's water needs. It is currently being tested by the South African Bureau of Standards.

waoh

hope this device work

I think this is a good news.