Ironically, many of the places that most require water purification have the least-developed infrastructure. That’s where a new filtration device comes in, as it’s activated by the sun – and it’s said to perform better than other solar-powered purification systems.
One of the most common ways of using the sun to purify water involves setting up what’s known as a solar still. Although there are several different types of solar still, they’re all based around the concept of collecting pure condensed water vapor that evaporates out of tainted liquid water as it’s heated by the sun.
While such setups are effective, they can sometimes take a long time to produce a decent amount of drinkable water. Seeking a faster-acting alternative, scientists at Princeton University have developed an inexpensive flat sponge-like device that draws in water from a lake or pond, then releases purified water when subsequently set in the sunlight.