June 3, 2009 While clean, safe water is in short supply in much of Africa, there's no shortage of sun. The Solaqua is a nifty portable device that uses the sun's rays to purify contaminated water. Through innovative use of readily available materials, it carries, disinfects and stores water, providing a safe, environmentally sustainable source of water for rural communities.

Millions of deaths each year from water-borne and water-related pathogens could be prevented with clean water, sanitation and hygiene.

Diseases such as cholera, typhoid, dysentery, and malaria are rife in sub-Saharan Africa where two in five people lack safe water for drinking and washing hands, food and utensils. Diarrhoea is the leading cause of death in babies, who are 520 times more likely to die than babies in Europe.

Access to uncontaminated water would help to reduce the incidence of diseases. Trachoma, for instance, which causes blindness, results from poor sanitation and a lack of water to wash hands and faces regularly. There are about 6 million new cases of preventable trachoma each year in Africa.

Solar water disinfection (SODIS) is a simple, low-cost way of improving the microbiological quality of water: heat and UV radiation work together to inactivate the pathogens that cause disease.

SODIS is recommended by the World Health Organisation (WHO) as a water-disinfection method for household use. While boiling water to reduce contamination requires fuel and fire, SODIS technology requires only the sun and empty PET bottles which are readily available. Studies have shown that the incidence of diarrhoea among SODIS users was reduced by 20 to 50 per cent.

The Solaqua is a SODIS device that can provide up to 10 liters of clean water at a time, the average amount of water used daily in rural Africa.

Raw or contaminated water is poured into the center of the device, where it passes through a sari cloth filter, an established method of reducing pathogens. It is then funneled into five angled bottles which are unhinged from the central unit and laid on the ground to allow maximum exposure to the sun. Each bottle has a black surface on the back that absorbs heat and reflective inner surfaces that reflect UV rays within the water, both of which help to purify the contaminated water more quickly. The bottles have screw-cap lids to help prevent re-contamination.

As water often has to be carried long distances, the Solaqua is ergonomically designed. In addition to the central handle, it features a double-sided handle so that it's easy enough for two children to carry. A hollow in the center of the five bottles also enables it to be carried in the traditional way on the head.

The Solaqua uses ABS plastic where extra strength is needed, for example, in the handle and bracket design, and PET plastic which enables the five bottles to gain maximum efficiency in UV exposure.

The Solaqua has been designed by Jason Lam, a student at the University of New South Wales in Australia. It was runner-up in the student division of the 2009 Australian Design Award - James Dyson Award announced on May 29.

Karen Sprey