NCEDA analysis of IDA World Congress technical sessions
Utilizing nanotechnology to enhance membrane performance for seawater desalination
Authors: Mr Christopher Kurth, Dr Robert Burk, Mr Jeff Green
Beginning with a quick overview of the history of the development of nanotechnology, Christopher Kurth moved to explain the principles behind the operational success that led to the synthesis of the first nano-particulate membranes for RO application. The increased permeability to water that arises with these membranes was found to be associated with the roughness of the nano-particulate surface and is essentially due to the increased surface area available to the water molecules. Delving deeper, a second layer of structure within this roughness was shown to enable the water molecules to travel through.
The next step towards developing a commercial product for seawater desalination plants was to produce a nanocomposite membrane on top of a supportive polymer layer. Rejection issues and fouling complicated the development of the final product and the team set out to work out where foulants and other particles were lodging in the nano-membrane. Defect channels in the membrane – areas where nano-particulate aggregate had formed during the initial membrane fabrication – appear to be the source of the problem. Continuing research in the fabrication process is expected to lead to further improvements to flux and increasing sulphate rejection.
Currently the team is targeting the finalisation of their research to bring it to commercial production with field validation via pilot modules and expanding the product line that it could yield membranes specifically designed to suit source water and/or product application.
