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Turning desalination waste into a useful resource

ScienceDaily (February 13, 2019)

Process could turn concentrated brine into useful chemicals, making desalination more efficient

Titre : Turning desalination waste into a useful resource

Process could turn concentrated brine into useful chemicals, making desalination more efficient

ScienceDaily (February 13, 2019)

Résumé
The rapidly growing desalination industry produces water for drinking and for agriculture in the world’s arid coastal regions. But it leaves behind as a waste product a lot of highly concentrated brine, which is usually disposed of by dumping it back into the sea, a process that requires costly pumping systems and that must be managed carefully to prevent damage to marine ecosystems. Now, engineers at MIT say they have found a better way.

Présentation
In a new study, they show that through a fairly simple process the waste material can be converted into useful chemicals — including ones that can make the desalination process itself more efficient. The approach can be used to produce sodium hydroxide, among other products. Otherwise known as caustic soda, sodium hydroxide can be used to pretreat seawater going into the desalination plant. This changes the acidity of the water, which helps to prevent fouling of the membranes used to filter out the salty water — a major cause of interruptions and failures in typical reverse osmosis desalination plants.
Sodium hydroxide is not the only product that can be made from the waste brine : Another important chemical used by desalination plants and many other industrial processes is hydrochloric acid, which can also easily be made on site from the waste brine using established chemical processing methods. The chemical can be used for cleaning parts of the desalination plant, but is also widely used in chemical production and as a source of hydrogen.

Story Source  : Massachusetts Institute of Technology

Annonce (ScienceDaily)

Page publiée le 11 avril 2019