Researchers at Pusan National University have created an innovative membrane technology using a multifunctional design to advance solar-powered seawater desalination, addressing challenges in a sustainable manner.
As global populations grow and industrial expansion continues, many nations in Africa, the Middle East, and Southeast Asia are facing a crisis of freshwater scarcity. Finding sustainable methods for producing clean water has become a pressing priority, with solar-driven desalination emerging as one of the most promising approaches. By harnessing sunlight to evaporate and purify seawater, this technology can offer efficient freshwater sources for water-stressed regions. However, seawater contains more than just salt. Coastal waters near ports and industrial areas are often contaminated with oil, which can clog the specialized membranes used in desalination systems. Although many experimental desalination platforms have shown promising results, most have been tested under laboratory conditions using clean brine. Consequently, their performance in real-world seawater remains unclear.
To tackle this challenge, a research team led by Professor Sanghyun Jeong from the Department of Civil and Environmental Engineering at Pusan National University in South Korea has developed a new multifunctional hydrogel membrane for solar-powered seawater desalination. The study was published online on June 1, 2026, and will appear in the journal Desalination Volume 636 on October 15, 2026. Instead of treating oil-water separation and desalination as separate processes, the researchers designed a single membrane structure capable of performing both functions simultaneously. The membrane features a "Janus" (two-faced) structure, meaning its two sides have different properties. One side is hydrophilic, made from a chitosan and polyvinyl alcohol hydrogel, allowing water to pass through while repelling oil droplets. The other side is hydrophobic, containing copper oxide nanoparticles encased in a carbon shell, embedded within a nanofiber layer. This side absorbs sunlight, converts it into heat, and drives surface water evaporation. Since each layer focuses on a specific task, oil rejection and heat generation do not interfere with each other—a scenario that could occur in a single-layer design.
Experiments demonstrated that the membrane removed over 99.99% of oil from contaminated seawater, while maintaining stable performance across different oil droplet sizes and under repeated use conditions. During solar-powered desalination, its evaporation rate reached 1.29 kilograms of water per square meter per hour, nearly three times that of traditional single-layer membranes. Professor Jeong stated, "By harnessing renewable solar energy and integrating pollutant separation with freshwater production on a single membrane platform, our technology has the potential to reduce energy consumption, operational complexity, and secondary waste generation, contributing to more sustainable water treatment and freshwater production."
The researchers believe that the membrane developed in this study offers a broader design concept for future water treatment technologies. Professor Jeong explained, "Beyond the specific application of desalination, the broader significance of this work is demonstrating how multiple treatment functions can be rationally integrated into a single membrane structure." Such multifunctional systems could help make solar water treatment more practical in contaminated coastal waters and industrial wastewater, while also facilitating the recovery of useful resources from concentrated brine. Continued research in this field is expected to advance a future where freshwater resources are readily available worldwide.
Comments