TECHNOLOGY > SODIS
SODIS (Solar Water Disinfection)
The drinking water situation is precarious in Kibera. Diarrhoeal diseases
are transmitted through contaminated drinking water. SODIS can contribute
to improve this precarious situation.
SODIS is cheap and practical water treatment method which uses solar energy to improve the microbiological water quality. It is used at household level to treat small quantities fo drinking water. SODIS was developed by the EAWAG Institute in Switzerland and is promoted by SANDEC ( www.sandec.ch).
For detailed information on SODIS please visit www.sodis.ch.
What is SODIS?
- A treatment method to eliminate the pathogens which cause water-borne diseases
- Ideal to disinfect small quantities of water used for consumption
- A water treatment process depending on solar energy only
- An alternative water treatment option for use mainly at household level
- An old but so far hardly applied water purification method
A grandma with her grandchild
proud to use SODIS in Kibera.
SODIS does not
- change the chemical water quality
- change the odour nor the taste of the water
- increase the water quantity or reduce water shortages
Limitations of SODIS
- SODIS is not useful to treat large volumes of water
- SODIS requires relativly clear water (turbidity less than 30 NTU)
- SODIS needs solar radiation (exposure time 6 hours under bright or up to 50% cloudy sky, or 2 consecutive days unter 100% cloudy sky)
SODIS is ideal to treat small quantities of water. Contaminated water
is filled into transparent plastic bottles and exposed to full sunlight
for six hours.
Sunlight is treating the contaminated water through two synergetic mechanisms: Radiation in the spectrum of UV-A (wavelength 320-400nm) and increased water temperature. If the water temperatures raises above 50°C, the disinfection process is three times faster.
Description of project areas where SODIS is implemented: