It is estimated that 844 million people have no access to clean water, and every minute a newborn dies due to infection due to a lack of safe water and an unclean environment.
Desalination of seawater and waste water recycling are two ways to alleviate the problem of water scarcity, but conventional approaches are energy-intensive and are based on combustion of fossil fuels. In fact, about 3% of the world's energy supply is used to clean water.
Researchers at Monash University have developed energy-passive technology capable of delivering clean, drinking water to thousands of communities, simply using photothermic materials and the power of the sun.
Researchers, led by Professor Xiwang Zhang of the Monash University of Chemical Technology, developed a robust solar steam production system to achieve efficient and constant production of pure salt water with almost 100% salt removal. By carefully checking salt crystallization just at the edge of the evaporation disc, this new design can also collect salts.
The feasibility and sustainability of the model were confirmed using seawater from the Lacepede Bay in South Australia. This technology is a promising solution for water scarcity in regional areas where electricity is not available.
The findings were published in the international journal Energy & Environmental Science.
"Water safety is the biggest challenge facing the world in the 21st centuryst in particular, due to the increase in the number of population and the shaping of the effects of climate change. Communities that are developing and lacking resources most feel the effects of these factors, "said Professor Zhang.
"The use of solar power for water purification has been widely established as one of the sustainable solutions to addressing the lack of clean water in some communities, without sacrificing our environment or resources.
"Despite considerable progress in materials development, the evaporation process has been hampered by the concentration of salt on the surface, which affects the quality of the produced water."
The researchers created a disc with super-hydrophilic filter paper with a layer of carbon nanotubes to absorb light. The cotton thread, 1 mm in diameter, operated as a water conveyor channel and pumped salted water onto the evaporation disc.
Brine the salt water with a cotton thread from a bulk solution into the middle of the evaporation disc. The filter paper captures clean water and the remaining salt is pushed to the edges of the plate.
The absorption of light was measured at 94% across the entire solar spectrum. The panel also showed a rapid rise in temperature when exposed to light in both dry and wet conditions, increasing from 25 ° C to 50 ° C and 17.5 ° C to 30 ° C in one minute.
This technology also has great potential in other areas, such as industrial waste water, empty liquids, sludge disposal, management of mining waste and recovery of resources. Future studies will try to extend technology to these applications with industry support.
"Our results of the study are progressing a step further to the practical application of solar steam technology, which proves the great potential for desalination of seawater, the recovery of wastewater and zero emissions," said Professor Zhang.
"We hope this survey can be the starting point
/ Public announcement.