Carbon nanotubes arranged in a hexagonal confi-
guration.
Photo by CSIRO Molecular & Health Technologies.

New membrane technology that would halve the amount of energy required to desalinate seawater is the goal of the latest Water for a Healthy Country Flagship initiative involving CSIRO and nine Australian universities.

The Advanced Membrane Technologies for Water Treatment Research Cluster, led by Professor Stephen Gray of Victoria University, will investigate carbon nanotube technologies in developing the new energy efficient membranes.

‘Many desalination and recycling programs rely on reverse osmosis, where thewater is forced through a semi-permeable membrane, removing salts and any other contaminants,’ Professor Gray says.

‘These membranes need regular replacement and cleaning, but they also require a large amount of energy to force water through the nano-sized pores.

‘We aim to improve membrane design to increase energy efficiency and reliability.

‘We also aim to improve membrane anti-fouling properties. When contaminants are removed from water, some adhere to the surface. These build up, increasing the pressure and energy required.’

Alan Gregory, Urban Water Research Leader at CSIRO, says the new membrane technology could also be used to treat wastewater.

Carbon nanotubes are sheets of carbon atoms tightly rolled into tubes the diameter of only a few water molecules.

The smooth inner walls of these nanotubes allow liquid to flow through, while the ultra-tiny pore size keeps out larger molecules. This reduces pressure requirements and saves energy and costs compared to reverse osmosis.

Apart from Victoria, the other universities involved are NSW, Monash, Melbourne, RMIT, Queensland, Deakin, Murdoch and the Curtin University of Technology.