Turning saltwater into drinking water by using a new kind of membrane which is more porous. The membrane (MOF) blocks the salt ions but lets the fresh water through.
Water scarcity is a major problem across the world. “It affects every continent,” says Amir Barati Farimani, an assistant professor of mechanical engineering at Carnegie Mellon University. “Four billion people live under conditions of severe water scarcity at least one month of the year. Half a billion people live under severe water scarcity all year.”
Yet even as people struggle without access to safe drinking water, there are oceans of undrinkable water right outside their doors. “71% of the world’s surface is covered by seawater,” Barati Farimani says. “So this is a very interesting contradiction.”
In order to combat this problem, Barati Farimani has focused his research on water desalination. This is the process in which salty seawater can be transformed into fresh water.
There are many ways to desalinate water, but one of the most effective is membrane desalination. In this method, water is pushed through a thin membrane with tiny holes. The water flows through the pores, but the salt ions can’t, leaving only fresh water on the other side.
In his latest research, Barati Farimani explores the potential of a new type of membrane, called a metal-organic framework (MOF). “These membranes consist of both the metal center and organic compound,” Barati Farimani says. The organic compound and metal connect in a pentagonal pattern, leaving a hole in the center that serves as a pore. “If you look at them, they are like a honeycomb,” Barati Farimani adds.
There are a couple of reasons why the framework is more effective. First, it’s incredibly thin. It’s a few atoms thick, which means there’s very little friction as the water molecules pass through the pores.
Read full article A more efficient way to turn saltwater into drinking water
Source: Phys.Org by Anna Boyle, Carnegie Mellon University Mechanical Engineering
Image: A conductive metal-organic framework (MOF) is a new type of membrane for turning saltwater into drinking water. Credit: Amir Barati Farimani, Carnegie Mellon University
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