SODIS (Solar Disinfection) is the act of disinfecting water solely through UV radiation. SODIS is, quite literally, leaving a water bottle in the sun for several hours; it’s implicitly simple. Because of its simplicity, however, user confidence in SODIS has been low and that has led to mistreatment of water and consumption of contaminated water in many cases. Four Villanova College of Engineering graduate students—Javier Urquizo and Viviana Villavicencio (Electrical and Computer Engineering), and Christa Cook and Wesley Shugart-Schmidt (Sustainable Engineering)—are working alongside Dr. Pritpal Singh to address the issue with their product “SoCo for SODIS” (Solar Confidence for SODIS).
How SODIS Works:
- Disinfection by photovoltaics, heat or UV radiation = low cost, low effort
- Transparent PET (plastic) bottles are filled and placed in direct sunlight for 6–48 hours
- UVA rays from sunlight inactivate biological contaminants (e.g., bacteria, viruses, protozoa, worms) = water is safe to drink!
- Low user confidence leads to improper disinfection
- Variability in sunlight concentration based on weather and location leads to variability in disinfection time
- No user-friendly, sustainable, large-scale means of verifying the bottle is disinfected
SoCo for SODIS:
- Offers a different means of testing water quality as it can be used on a community level testing several bottles at once
- Distributing the total capital cost throughout the community makes the per-household cost affordable
- UV sensors measure the intensity and quantity of light impacting the PET bottles and an Arduino LCD display informs the user if the bottle has been exposed to enough light
- Buttons on the Arduino allow users to add more PET bottles and easily select which bottles are being displayed to prevent confusing contaminated and decontaminated water
Urquizo, Cook, Shugart-Schmidt and Villavicencio submitted a SoCo for SODIS proposal to IEEE’s SIGHT competition and were one of two winners awarded a grant of $1,000 for initial funding. This grant will allow the team to continue with weatherizing and streamlining SoCo, moving towards general production to reduce costs, and implementation in communities to gather feedback and refine the design. Cook says, “SoCo will increase user confidence and improve SODIS practice.” She adds, “It feels great to see our idea validated by the IEEE community. We have been working on this project since August, and with this award we will be able to continue to develop the technology through weatherization and exploring IoT possibilities.”