SODIS
Practical Action
A bucket lined with aluminium foil can act as a solar collector, increasing the
efficiency of heating quite dramatically.
Filling the bottles 75% first and shaking the bottle for 20 seconds increases the
oxygen in the water, which, combined with the UV radiation helps to fight pathogens.
Fill the rest of the water after shaking the bottle.
Bottles should be placed horizontally and not upright, nor should the bottles be half
full.
Always replace scratched and old bottles.
Limitations
Weather dependency is the biggest limitation of SODIS. Since the application is quite
weather dependent requiring bright sunlight, the process cannot be carried out during rainy
days. It is recommended that during long rainy spells, the household should resort to boiling
or pasteurising the water.
Another limitation is that a large quantity of water cannot be heated up through this process.
PET bottles larger than 2 litre volume should not be used.
SODIS water can be consumed by children, healthy adults and even the aged. But, care must
be taken in the case of infants (less than 18 months), very sick children or adults,
malnourished children and those suffering from reduced immunity (such as AIDS). For these
categories, boiled and cooled water is recommended.
References and further reading
Solar Water Disinfection: A guide for the Application of SODIS Department Water &
Sanitation in Developing Countries, Swiss Federal Institute Of Environmental Science
& Technology
Solar Disinfection of Water – a Case Study from Kenya Stephen Burgess and Collins
Onyonge Waterlines Vol. 22 No 4 April 2004
Promoting SODIS in Guatemalan Villages Sharon Price, Liasa Rudge, Este Capilla
Prades Waterlines Vol. 22 No 4 April 2004
Water quality and treatment a selection of Practical Action Technical Briefs
SODIS
EAWAG/ SANDEC
Martin Wegelin
Regula Meierhofer
Ueberlandstrasse 133
CH-8600 Duebendorf
Switzerland
Tel: +41 1 823 50 19
Fax: +41 1 823 53 99
E-mail: wegelin@eawag.ch
Website: http://www.sodis.ch/
Swiss Federal Institute of Environmental
Science and Technology (EAWAG)
P.O. Box 611
Ueberlandstrasse 133
CH-8600 Duebendorf
Switzerland
Tel: +411 823 55 11
Fax: +41 1 823 50 28
E-mail: info@eawag.ch
Website:
http://www.eawag.ch/e_welcome.html
Department of Water and Sanitation in
Developing Countries (SANDEC)
Ueberlandstrasse 133
P.O. Box 611
CH-8600 Duebendorf
Switzerland
Tel: +41 1 823 52 86/823 50 18
Fax: +41 1 823 53 99
E-mail: caterina.dallatorre@eawag.ch
Website: http://www.sandec.ch/
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