Nanotechnology for Water Filter

Photo: Photo of a carbon nanotubes

Carbon nanotubes possess exceptional electronic, mechanical and chemical properties, for example they can be used to clean polluted water. Among many potential applications, carbon nanotubes are great candidate materials for cleaning polluted water. Many water pollutants have very high affinity for carbon nanotubes and pollutants could be removed from contaminated water by filters made of this nanomaterial, for example water soluble drugs which can hardly be separated from water by activated carbon.

Problems due to filters’ saturation could be reduced as carbon nanotubes have a very large surface area (e.g. 500 m2 per gram of nanotube) and consequently a very high capacity to retain pollutants. “Maintenance and wastes related to water depollution could thus be reduced”, says Thilo Hofmann, Vice Dean of the Faculty of Earth Sciences, Geography and Astronomy of the University of Vienna.

A lot of research has focussed on carbon nanotubes in the past decade. However, the exceptional properties of carbon nanotubes make them difficult to study. Standard methods give limited results and the behaviour of carbon nanotubes in realistic conditions is still poorly understood.

A team of researchers at the Department of Environmental Geosciences at the University of Vienna is currently carrying out research on the subject. They developed a method called "passive sampling". Data produced by this new method are much more reliable for realistic applications as they include concentrations likely to occur in the environment (generally very low). This was not possible with classical methods that can only deal with elevated concentrations. The experiments published now took more than a year.; Source: University of Vienna