British engineers have developed a simple water filter which could save thousands of lives in developing countries.
Unlike the commercial water filters currently supplied by some charities, the unit designed by Dr Paul Sallis and colleagues at Newcastle University, UK, can easily be made by local craftsmen and women, using local materials.
The 'low tech' manufacturing process overcomes the problems of having to persuade and educate low-income families to use water filters and of having to order costly spare parts when a filter breaks down.
But after successful trials, the project has not been widely implemented because it does not qualify for support from the development agencies, falling into a 'no man's land' between research and commercial products.
Charities estimate that more than a billion people do not have access to safe drinking water. In some parts of Africa, water-borne diseases such as cholera, dysentery and viral diarrhoea claim the lives of one in four children.
The United Nations has deemed such infant mortality rates as unacceptable. One of its eight Millennium Development Goals is to 'reduce by two-thirds the mortality rate among children under five'. This goal is one of the keynote topics at the 2006 World Water Congress in Beijing, today, Monday 11 September.
The Newcastle project began after a group of postgraduate civil engineering students visited Ghana, Kenya and Malaysia and recognised the huge benefits that sustainable water filtration could have on health. One of the students, Matt Simpson, decided to devote his doctoral research project to this topic.
Working in the laboratories at Newcastle University, he tested many techniques and eventually discovered that a mixture of clay and crop residues - such as rice husks or bran - created the ideal ceramic filter, when fired at 700 to 1,000C.
At these temperatures the crop residue decomposes, releasing carbon dioxide gas which forms microscopic pores in the ceramic material exactly the right size to trap bacteria and viruses but allow water to pass through.
Tests showed that the filter trapped 99.99 per cent of pathogens - equal to the efficiency of commercial filters which rely upon the addition of biocides, such as compounds of silver, to the clay before firing. This makes them more expensive and requires more advanced technology in the manufacturing process.
Low-income families in developing countries cannot afford to buy commercial water filters. Some charities distribute them free of charge but uptake is low and they tend to be discarded when new parts are needed.
The Newcastle filter, however, can be made by local potters using local materials - and even the most primitive open-air 'bonfire kiln', in which the pottery is fired in a rack surrounded by burning wood, can reach sufficiently high temperatures.
Mr Simpson has since spent a six months placement at the International Centre for Diarrhoeal Disease Research in Bangladesh, training village potters to make the filters. The project proved how easily the technology could be adopted. The placement was funded by a £20,000 grant from HSBC Holdings PLC, which supports environmental research at Newcastle University as part of its commitment to 'green' technologies and sustainable development.
Newcastle University is one of the founding members of the HSBC-funded Partnership in Environmental Innovation (PEI), which has also seen the establishment of the first Chair of Environmental Technologies and Geothermal Energy at Newcastle, Professor Paul Younger.
Dr Sallis, a lecturer in the university's School of Civil Engineering and Geosciences and a leading expert in water treatment technologies, said: 'Pottery manufacture is one of the world's oldest professions and most places have the basic materials and skills required to manufacture simple ceramics. It takes only two hours to teach a potter to make one of our filters from the resources already available in their village.'
Having proven the theory, the next step would be to launch a training and education programme, so that village potters start making the filters and local people recognise the benefits of using them.
However, the resources necessary to launch such a programme have so far proved impossible to obtain.
Dr Sallis said development agencies are swamped with applications for support and tend to select projects with economic development potential, for example a product which local craftspeople can make and sell for a profit.
'It is very difficult for us to demonstrate that local people could make a profit from our water filters,' he said. 'To be sustainable, we need to spread knowledge and educate people. This would involve local potters showing each other how to make the filters, which is contrary to the commercial principle of keeping your methods secret from your competitors.'
In May 2006, the project reached the last 125 out of 2,500 applications for a grant award from the World Bank but in the end just failed to get funding .
Dr Sallis said: ''Funds are available for research and for the distribution of finished products but unfortunately we fall in a no-man's land between the two.'
'Ceramic water filters offer great potential for reducing the pathogen intake by people with low quality drinking water, and are therefore one of the most promising options to address United Nations Millennium Development Goal targets for reducing infant mortality.'
Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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