While two thirds of the world’s population may face water shortages by 2025, according to an article from Science Magazine, water desalination plants that turn salt water into fresh drinking water have never been a feasible option for most communities due to their prohibitive cost. But that could soon change. Chinese researchers have improved on an old solar-powered technique known as a solar still that may put small-scale desalination systems back within reach, even for individual households.
Solar stills are large containers covered by clear plastic or glass that direct sunlight onto salt water. The water evaporates and then condenses on the plastic or glass where it is retrieved, while the salt is left behind. Because the method is slow and produces very little fresh water, researchers have tried topping the water with particles of gold, a good absorber of sunlight, for more efficient evaporation, according to the article. The method is effective, but the gold is expensive. Now, Chinese researchers have taken this approach a step further and have replaced the gold with cheap and abundant aluminum, which works similarly to boost evaporation. Using aluminum, researchers were reportedly able to purify salt water up to three times faster than without the material.
The technology still needs work and it isn’t likely to replace industrial filtration in the near term, according to Science, but it may offer an inexpensive way for individuals in developing countries to purify water for their own needs.
Read the entire article here.