Solar disinfection for water purification
Amanda M. Icazatti Burtell
Fernando Pacheco Ocasio
University of Puerto Rico - Cayey
What is the SODIS Method?
• Solar Disinfection for Water Purification (SODIS)
• Why use the SODIS Method?
• Simple procedure
• Kills pathogens
• What kind of pathogens?
S.C. Rivera, T.C. Hazen, G.A. Toranzos. 1988. Isolation of Fecal coliforms from pristine sites in a tropical rain forest.
Why is important to have purified water?
•1.1 million people do not have access to safe water
•Diarrhea is the second main cause of death
among children under 5 years old.
How does the SODIS Method work?
• Water sample
• PET bottles
• UV rays from sunlight
• 6 hours full exposition
• Finally, Drink purified water!
• How recontamination is prevented?
• What are some problems that the SODIS
Method may confront?
• Cloudy days
• Rainy days
How is contamination tested in
• Coliphages ( E. coli)
• Why use coliphages as an indicator of
contamination in the water sample?
• What would a positive coliphages result
for E. coli indicate?
• Will the SODIS Method be proved to reduce the
presence of pathogens (coliphages) in water samples
and make water safe to drink?
• The SODIS Method will be proven with empirical
evidence to reduce the presence of pathogens
(coliphages) in water samples making water safe to
PET Bottles Host bacteria: E. coli Medium Broth
Petri dishes Multimeter UV Rays Machine
Choose a place Measure water for
pressure & oxygen
Collect 800 mL of water
Sterilize PET Bottles
Transfer water sample to PET Bottles50 mL per PET Bottle
Prepare bacteria, medium &
15 minutes for agar solidification
Incubate at 37˚C for 24 hours
• 4 hours after incubation at 37˚C
• What does the presence of bubbles indicate?
pH Temperature Atmospheric
8.34 24.8˚C 730.7 mmHG
• 19 ½ hours after incubation
Control: 0 minutes Control: 10 minutes
Experimental: 0 minutes Experimental: 10 minutes
• Water samples from Rio La Plata, Cayey were collected
and tested for coliphages.
• The SODIS Method was not performed effectively using a
UV light machine.
• Samples were incubated at 37˚C for a period of 24 hours.
• Samples were analyzed after 4 hours, 19 ½ hours after,
and 24 hours of incubation.
• Repeat SODIS Method using UV Rays from sunlight
• Perform SODIS Method for Enterococcus to investigate if
there is any human fecal pollution in Rio La Plata, Cayey.
• We want to thanks the RISE Program for this learning
• Prof. Javier Arce for letting us participate in water
sampling testing experiments.
• Jennifer Paredes for the all the help, time dedicated, and
• Giovanni Cruz for letting us use the laboratory and the
UV rays machine.