This commentary, by South African scientists Thembela Hillie and Mbhuti Hlophe, examines nanoscience's potential to solve the technical challenges associated with removing pollutants from water. The authors describe a range of nano-based water treatment technologies already in the marketplace and discuss how nanofiltration membranes can be used in low-cost methods to produce safe drinking water. They highlight a case study in South Africa where such membranes were used to treat brackish groundwater.

The authors emphasise the importance of technology transfer in getting nano-based solutions to the countries that need them, arguing that direct transfer does not often work. Rather, what developing countries need are approaches that combine technology transfer with technology adaptation and adoption — involving local stakeholders in establishing water treatment devices and developing local capacity to use them.