Sustainability August 17, 2016

Graphene oxide membranes for water desalination

Desalination of salt water was historically done by evaporating the water to separate it from salt, then condensing it.

Polyamide Membranes

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Membrane desalination

Evaporation and condensation is energy-intensive. Polyamide membranes are now used to desalinate water using reverse osmosis. This process is much less energy-intensive.

Although relatively cheap, polyamide membranes have their own disadvantages

  • The wastewater produced has a high salt concentration and requires special disposal
  • The membranes can grow bacteria in the absence of chlorine
  • The membranes can degrade in the presence of chlorine

Graphene Oxide

Graphene oxide is being touted as a possible replacement for polyamide membranes. Membranes made from graphene oxide are cheap, and thinner than polyamide, thus requiring less energy to pump water through them. They can also withstand harsh chemicals and high temperatures though they cost up to 5 times more than polyamide membranes.

Read more at Science News.

About the author

Dr Q Warren: