Improving Harvesting Fog to Collect Clean Water

Fog on the St. Johns River (Florida), taken at...
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According to the World Health Organization, nearly 900 million people worldwide live without clean drinking water.

MIT might have solved this problem by using the fog. MIT has an easier and improved fog-harvesting materials that could solve the problem of drinking water in the countries that suffer from that problem.
They can collect water from morning dewdrops or coastal water vapor.

MIT engineer
Shreerang Chhatre is designing devices that attract water droplets and pool them together.

Chhatre has been studying the materials used in fog-harvesting devices, which typically consist of a fine mesh panel that attracts droplets, which collect inside receptacles. Chhatre is studying the “wettability” of materials, seeking a combination that attracts and repels water. Fog harvesters would not do much good if they only soaked up water; you’d also need a surface that repels it so it can be collected later.
Fog harvesters are already available in Chile, where they are made of a nylon or polypropylene netting, according to the Organization of American States, which has promoted the technology in Chile, Peru, Ecuador and Guatemala, among other places. The concept is at least 30 years old, but Chhatre has recently published papers in which he describes improving the efficacy of some fog harvesters. They work best in coastal regions, where winds move water vapor inland. But Chhatre is testing materials that could also work in arid climates that experience early morning fog, and in high-altitude areas where moisture collects on mountains and in valleys. In some tests, fog harvesters have captured one liter of water (roughly a quart) per one square meter of mesh, per day, according to MIT. Several high-tech solutions promise to provide potable water for the world’s poor, yet they are often expensive, cumbersome or otherwise impractical. Fog nets could be a simpler solution, Chhatre believes — as long as there’s enough investment to develop the technology. That’s where developed countries come in: Environmentally conscious communities might try fog harvesting to reduce the costs and emissions associated with transporting water and powering massive water treatment facilities.