Fresh water can be hard to come by in some parts of the world, even in parts of the United States. And, of course, you can’t drink salt water, which is unfortunate because there certainly is a lot of it. As such, humans have struggled for years to find ways to desalinate ocean water, to remove the salt and have water left over that we can actually drink.
Scientists have developed some systems to do this, but frankly, they aren’t very efficient. One model, called reverse osmosis, involves screening the salt water through a fine membrane, which leaves the salt on one side and the water on the other. Unfortunately, this has one downside. Membrane separation leads to a problem called “biofouling,” in which biofilms form on the membrane’s surface, which prevents water from passing through. Over time, the membranes become useless as they let less and less water though. Normally, the membranes are cleaned with sodium hypochlorite, which contains chlorine. The chlorine doesn’t impact people who drink the water, but it does damage the membrane itself, meaning they have to be replaced rather often.
A team at Hiroshima University might have developed a solution to this problem. They are working on a membrane project called ROBUST, which they think can solve a lot of desalination issues. Their new membrane is strong enough to withstand the chlorine needed to clean it. It is also heat resistant, and they aren’t done with it yet. So far they’ve focused on the silicon based membranes, but they also plan to make use of hydrocarbon and chemical vapor deposition. By combining these three technologies, they expect to make efficient, long-lasting, and environmentally friendly desalination equipment.
Desalination technology will become increasingly important over the rest of the century, as fresh water becomes harder to maintain thanks to global climate change. This new membrane should be a pretty big deal.