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An Indian woman carries a plastic container filled with water in New Delhi in a slum area in New Delhi, India.
Bernat Armangue/AP
Water & Sanitation

This Low-Cost Device Purifies Water Using Only Paper and Sunlight

A team of researchers from the University of Buffalo has developed a new technology that can purify water using sunlight.

This technology, which is a modern-day take on the ancient concept of a solar still, drapes a sheet of carbon paper in a triangular form over the top of some water. The ends of the paper then absorb the water.

Through the device, sunlight evaporates the water from the paper, but leaves the contaminants behind. The water vapor then cools and condenses to become liquid water again — without its initial impurities.

Take Action: Urge Governments And Businesses To Invest In Clean Water And Toilets

The new device can evaporate about 2.2 liters of water per hour, for every square meter of paper hit by the sun, according to the University of Buffalo.

This sort of solar still is more efficient than other solar-powered water purifiers, according to Qiaoqiang Gan, an engineering professor who led the study

In full sun conditions, the team’s prototype can condense and collect between 10 and 20 liters per day, the university reported.

Read More: Solar Power Could Save Water in Thirsty Middle East and North Africa

The hope is that this method will be cheaper than other technologies out there, while remaining extremely effective. The device will be available for purchase for about $200 within about a year, Gan estimated. He hopes this method would provide an inexpensive alternative to other recent technologies that require costly nanomaterials.

"Solar energy is basically free," Gan told Smithsonian magazine. "In some countries in tropical areas, they are short of resources but they have an abundance of solar energy."

This method would work with any kind of water, including lakes, ponds, and oceans, but how it works with each type of water will be dependent on a few factors.

Read More: This Solar-Powered Device Turns Air Into Water

If used with ocean water, for instance, salt will gather on the surface, so the team is still working out a number of design details to accommodate for various settings.

The device can remove almost all bacteria, viruses and organic compounds from water, but still struggles to remove certain volatile chemicals like pesticides, according to Smithsonian.

There’s an estimated 844 million people living without access to safe water. That accounts for one in nine people around the world, according to Water.org.

Read More: Scientist in India Develops One-Step Water Contamination Test

Lack of clean water and sanitation directly affects the health and well-being of all people. A child under 5 years old dies every two minutes from diarrhea caused by dirty water and lack of clean toilets. Infections caused by unsafe water and a dirty environment result in the death of a newborn every minute, according to WaterAid.

Global Citizen campaigns in support of Sustainable Development Goal 6, to ensure availability and sustainable management of water and sanitation for all. You can take action here.