Billions could gain access to freshwater with new desalination technology

Billions could gain access to freshwater with new desalination technology
by Simon Mansfield
Sydney, Australia (SPX) Dec 05, 2024

A major leap in desalination technology could help billions of people worldwide access freshwater, thanks to an innovative method that accelerates seawater evaporation more effectively than freshwater.

Currently, up to 36% of the global population faces severe freshwater shortages for at least four months annually, and this figure could climb to 75% by 2050. Addressing this growing crisis, seawater desalination has emerged as a vital solution. However, traditional desalination methods are energy-intensive, leaving significant carbon footprints.

Researchers at the University of South Australia (UniSA), in collaboration with Chinese scientists, have developed a groundbreaking approach using a photothermal hydrogel evaporator enhanced with inexpensive clay minerals. This innovation boosts seawater evaporation rates by 18.8% compared to pure water, a stark contrast to earlier studies where seawater evaporation rates lagged 8% behind freshwater.

Professor Haolan Xu of UniSA, a leading materials science expert, explained the mechanism behind the advancement: "The key to this breakthrough lies in the ion exchange process at the air-water interface. The minerals selectively enrich magnesium and calcium ions from seawater to the evaporation surfaces, which boosts the evaporation rate of seawater. This ion exchange process occurs spontaneously during solar evaporation, making it highly convenient and cost-effective."

With over 17,000 desalination plants worldwide, even minor improvements in evaporation efficiency could save millions of tons of freshwater annually. The team's innovation is both sustainable and easily adaptable to current evaporation-based systems.

"The new strategy could be integrated seamlessly into existing desalination technologies, providing access to massive amounts of clean water and benefitting billions of people worldwide," Prof Xu said.

The hydrogel evaporator proved durable, maintaining performance after prolonged exposure to seawater. The research team is now focused on exploring further enhancements to optimize evaporation rates and apply them in practical desalination systems.

Research Report:Making Interfacial Solar Evaporation of Seawater Faster than Fresh Water