14-year-old Deepika Kurup invented a solar-powered water purification system for the Discovery Education 3M Young Scientist Challenge. She won $25,000 for her low-cost system, which exposes titanium oxide and zinc oxide to the sun, creating a chemical reaction that generates hydroxyl radicals. These can kill harmful bacteria in water, purifying it by significantly reducing the coliform units and E.Coli colonies.
Co.Exist reports that Kurup tested the purification system in her backyard with contaminated water from a wastewater treatment facility. Her composite costs about half a cent per gram, and this method can generate fresh-tasting water off-grid. The young scientist next plans to apply for a patent and start up a nonprofit organization to deploy her system. You can see her talk about her invention in the video below: