SODIS is a water disinfection technique that uses UV radiation to kill microorganisms in the water. Small amounts of contaminated water are put into transparent plastic bottles and exposed to full sunlight for six hours, killing microorganisms through radiation and high temperatures. While the SODIS method has gained some traction in the developing world, it has two major limitations: it cannot disinfect turbid (murky) water, and it does not remove organic chemical contaminants such as pesticides and fertilizers.
This E-Team is developing a modification to the SODIS system. Their design consists of two buckets stacked on top of each other, with the first bucket containing layers of gravel, sand, and crushed charcoal, and the second bucket serving as a storage container. The team tested the design and showed that it significantly reduces both the turbidity of the water and the levels of microorganisms, pesticides, and fertilizer components.