A Way to Make Water Potable Using Carbon Dioxide
21st May 2017
Dr Stone’s alternative is to abandon the idea of filtration altogether. Instead, he plans to apply a phenomenon called diffusiophoresis to the problem. When CO2 and water meet at the liquid’s surface they react to make carbonic acid. This is a solution of hydrogen ions, which are positively charged, and bicarbonate ions, which are negative. The newborn ions then diffuse away from the surface and into the main body of the water. That creates a gradient of ionic concentration perpendicular to the surface. Dr Stone’s insight was that, because the gravity-resistant particles which need to be removed almost always have either positive or negative static-electric charges on their surfaces, their interaction with an ion gradient of this sort, which is itself composed of charged particles, could be used to move them around.
Fresh clean water, here we come.