The waste product of desalination, highly concentrated brine, is usually disposed of into the sea. MIT engineers are working on a commercial process that will instead convert this brine into useful chemicals. The brine would undergo nanofiltration and electrodislysis to create chemicals like sodium hydroxide and hydrochloric acid. Sodium hydroxide could make the process of desalination itself more efficient, by changing the acidity of seawater before it enters the desalination plant. The researchers are working with companies with the aim of building a prototype plant. Their concept is described in Nature Catalysis.