Finding a cheap and effective water purification process would have global implications.

A research team from the University of Texas at Austin’s Cockrell School of Engineering has developed a new cost-effective and compact technology that combines gel-polymer hybrid materials to improve the purification process for drinking water.

The new materials possess both hydrophilic—an attraction to water—qualities and semiconducting, or solar-absorbing properties. This enables the hydrogel to produce clean, safe drinking water from virtually any source, whether it’s from the oceans or contaminated supplies.

“We have essentially rewritten the entire approach to conventional solar water evaporation,” Guihua Yu, associate professor of materials science and mechanical engineering at The University of Texas at Austin, said in a statement.

The new hydrogel-based solar vapor generator uses ambient solar energy to power the evaporation of water for effective desalination.

Existing solar steaming technologies used to treat saltwater involve an expensive process that relies on optical instruments to concentrate sunlight. However, the nanostructured gels require far less energy and only need naturally occurring levels of ambient sunlight to run, while also being capable of significantly increasing the volume of water that can be evaporated.

“Water desalination through distillation is a common method for mass production of freshwater,” said Fei Zhao, a postdoctoral researcher working under Yu’s supervision, said in a statement. “However, current distillation technologies, such as multi-stage flash and multi-effect distillation, require significant infrastructures and are quite energy-intensive. Solar energy, as the most sustainable heat source to potentially power distillation, is widely considered to be a great alternative for water desalination.”

Water vapor is generated with the hydrogels under direct sunlight and then pumped to a condenser for freshwater delivery.

The researchers successfully tested the hydrogels on water samples from the salt-rich Dead Sea, reducing the salinity significantly in the samples after putting them through the hydrogel process, achieving levels that met accepted drinking water standards outlined by the World Health Organization and the U.S. Environmental Protection Agency.

“Our outdoor tests showed daily distilled water production up to 25 liters per square meter, enough for household needs and even disaster areas,” said Yu. “Better still, the hydrogels can easily be retrofitted to replace the core components in most existing solar desalination systems, thereby eliminating the need for a complete overhaul of desalinations systems already in use.”   

According to the United Nations, 30,000 people die each week from the consumption and use of unsanitary water, mostly occurring in developing nations.

The researchers also found that the hydrogels could be used to filter out a number of other contaminants found in water.

Yu also said the new technology could be commercialized and has filed a patent application for the hydrogels.