Researchers at Monash University have developed energy-passive technology that’s able to deliver clean, potable water to thousands of communities, simply by using photothermal materials and the power of the sun.
Researchers created a disc using super-hydrophilic filter paper with a layer of carbon nanotubes for light absorption. A cotton thread, with a 1mm diameter, acted as the water transport channel, pumping saline water to the evaporation disc. The saline water is carried up by the cotton thread from the bulk solution to the centre of the evaporation disc. The filter paper traps the pure water and pushes the remaining salt to the edges of the disc.
The light absorbance was measured to 94 per cent across the entire solar spectrum. The disc also exhibited a rapid temperature increase when exposed to light in both dry and wet states, rising from 25C to 50C and 17.5C to 30C respectively within one minute.
This technology has also great potential in other fields, such as industry wastewater zero liquid discharge, sludge dewatering, mining tailings management and resource recovery. Future studies will look to extend the technology to these applications with industry support.