Affordable water filtration

Cheap, efficient water filters can be produced by simple ceramic pottery techniques.
Researchers at Newcastle University in Britain have created a water filter, using production skills and materials readily available in developing countries. The pots, which measure 30cm in diameter are prepared from a mixture of clay and crop residue such as bran and rice chaff. They are then fired on a grid in a bonfire, where the vegetable residues decompose and release carbon dioxide.
As the pots cool, the gas creates microscopic holes in the clay which prevent the passage of bacteria and viruses while allowing water to pass through.
The ceramic filter is housed in a two-tier filter assembly with integrated water storage container below.
The researchers estimate that the filter can block 99.99% of disease-forming germs and claim that it is just as effective as commercially-available filters.
The technique has been tested at the International Centre for Diarrhoeal Disease Research in Bangladesh.
Email p.j.sallis@ncl.ac.uk
www.staff.ncl.ac.uk/p.j.sallis/ceramic2.htm