New water filter to safeguard clean water
Water purification ensures clean drinking water for humans. Dr Jiang Yi, Member of the Research Institute for Sustainable Urban Development (RISUD) and Assistant Professor in the Department of Civil and Environmental Engineering at PolyU, and his team have developed a new water filter which can significantly advance water purification technologies.
Their filters are devised from a new nanomaterial, graphene oxide (GO), a two-dimensional nanoscale sheet primarily made of carbon. GO nanosheets can be assembled into a membrane or filter. They have attracted growing attention from researchers due to their outstanding separation performance. However, the instability of the GO membrane, which arises from water-induced effects like swelling and poor interfacial adhesion to the substrate, has largely limited its separation performance and long-term applications.
To address this issue, Dr Jiang’s team developed a new “magnetically ultra-stabilised GO-based membrane filter”. They first decorated the GO nanosheets with in-situ formed magnetite nanoparticles, making the 2D materials magnetic. The team then used these materials to obtain a filter through a simple filtration method. They found that the filter could be ultra-stabilised above a permanent magnet. This marks the creation of a membrane filtration setup that remains intact under harsh ultrasonic destabilisation and turbulent hydrodynamic conditions. The membrane filter not only exhibits separation performance comparable to that of commercial ultrafiltration membranes, but also effectively inactivates waterborne pathogens (e.g., E. coli), thus achieving a suitable technology for many water purification applications.
The research work on the graphene oxide filter ultra-stabilised in a magnetic field was featured on the supplementary cover of the journal ACS ES&T Engineering (2022, 2, 5, 769–779).
