“How can we use pressure to purify seawater?”
Already humanity is facing a major water problem. As the water reservoirs start to dry up, there will be entire areas with no hydration to speak of. So what is one way we could solve this? Well, how about we look to the most plentiful form of water, the ocean, to solve our problems. Ocean water is normally unusable for humanistic concerns due to it’s salty nature, but what if we were to desalinate it to make it usable?
Now that we have the idea, let’s think about how we could make this a reality. Well, first of all, we should notice that salt water probably has other elements in it that are a result from exposure to the rest of the environment, such as seaweed and dead animals parts. These items are usually larger than the molecules of water and salt, so they can be filtered away easily through the use of a permeable layer. We can accomplish this by extracting sea water, and then using pressure to force it through a permeable layer. However, the leftover water will still have a high concentration of salt. But to our luck, it is still possible to separate the salt if we notice one factor, that both water and salt have different evaporation points, and more specifically, water has a lower point of evaporation. So what we can do with this leftover salt water is boil it until the point of evaporation for water, and then pass this steam off into another area, and then cool it until it solidifies again. After all of this, we will finally have ourselves some freshwater! This process is known as reverse osmosis, and plants are currently being used in arid regions such as California, Israel, and Saudi Arabia to create a usable water supply.