Safe drinking water is a basic human right – or, at least, it should be. Unfortunately, more than two billion people around the world don’t have access to it. (1) This is why finding sustainable solutions that can be easily implemented anywhere regardless of their access to an electrical grid are key. Back in 2020, this group of scientists came up with a way to purify water that is powered by the world’s most abundant natural resource: Sunlight.
We Can Create Safe Drinking Water For All Using The Power of The Sun
For decades, scientists have been attempting to solve the safe drinking water crisis that affects nearly every country in the world. As the climate continues to warm and change, this crisis will only continue to become worse. While there have been previous solutions, these have all tended to require large amounts of energy input via an energy grid. Unfortunately, this is not a viable solution for many of the most affected communities who do not necessarily have access to a reliable electricity grid. In 2020, a group of scientists from Australia and China solved this problem by creating a filtration system that uses sunlight to kick-start the filtration process rather than heat or electricity. (2)
How It Works
First of all, it is important to note that the process has specifically been designed to help remove the salt, as well as other contaminants, from salt water. This is due to the abundance of salt water on the Earth that has been largely unusable previously because of its salt content. Previous desalination processes, while effective, require a huge amount of energy input that has prevented them from being used on a large scale.
“Desalination has been used to address escalating water shortages globally. Due to the availability of brackish water and seawater, and because desalination processes are reliable, treated water can be integrated within existing aquatic systems with minimal health risks,” said lead author Professor Huanting Wan. “But, thermal desalination processes by evaporation are energy-intensive, and other technologies, such as reverse osmosis, has a number of drawbacks, including high energy consumption and chemical usage in membrane cleaning and dechlorination.” (3)
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The research team has created a filter using a highly porous material to extract the salt from salt water, as well as clean the water for any other unwanted substances. The material is a type of metal compound that is made of metal ions in a crystalline pattern, similar to the salt it is aiming to absorb. To kick-start the filtration process, the researchers created a system that uses sunlight to work rather than energy from a traditional electricity grid.
“Sunlight is the most abundant and renewable source of energy on Earth. Our development of a new adsorbent-based desalination process through the use of sunlight for regeneration provides an energy-efficient and environmentally-sustainable solution for desalination.” said professor Wang.
Durable and Sustainable
The team’s research shows that their filter, called a metal organic framework or MOF, is both durable and extremely efficient. With just one kilogram of their new MOF, they were able to create 139.5 of fresh, safe drinking water per day. This is far more efficient and sustainable than previous technologies, as well as it is much more durable.
“This study has successfully demonstrated that the photoresponsive MOFs are a promising, energy-efficient, and sustainable adsorbent for desalination. Our work provides an exciting new route for the design of functional materials for using solar energy to reduce the energy demand and improve the sustainability of water desalination,” said professor Wang. “These sunlight-responsive MOFs can potentially be further functionalised for low-energy and environmentally-friendly means of extracting minerals for sustainable mining and other related applications.”
While there is still a ways to go before these are ready for large-scale use, this could be a game changer for bringing safe drinking water to people all around the world.
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Sources
- “2.1 billion people lack safe drinking water at home, more than twice as many lack safe sanitation.” WHO. July 12, 2017.
- “A sunlight-responsive metal–organic framework system for sustainable water desalination.” Nature. Ranwen Ou, et al. August 10, 2020.
- “Breakthrough technology purifies water using the power of sunlight.” Eurekalert. Monash University. August 10, 2020.