"No More Drinking Water Worries for Remote Islands"... Development of Eco-Friendly, Ultra-Low-Cost Solar-Powered Seawater Desalination Device

Professor Kim Sungkyun's Team at Daegu Gyeongbuk Institute of Science and Technology

Professor Kim Seong-gyun (right) from the Department of Chemical Physics and master's student Lim Hong-seop, who developed a seawater desalination device at Daegu Gyeongbuk Institute of Science and Technology. Photo by DGIST

[Asia Economy Reporter Kim Bong-su] A domestic research team has developed a solar-powered seawater desalination device made from natural materials. Its low cost and simple structure are expected to help solve drinking water problems in remote island villages and similar areas.

On the 14th, Daegu Gyeongbuk Institute of Science and Technology announced that Professor Kim Sung-kyun's team from the Department of Chemical Physics developed a solar-powered seawater desalination material made from natural substances agar and nanocellulose. The material is biodegradable, inexpensive, regenerable after use, and uses solar energy as a power source, confirming the potential for a more eco-friendly seawater desalination technology.

Although Earth is a water-rich planet with 70% of its surface covered by water, 97% of it is seawater. Freshwater, suitable for the survival and consumption of living organisms, accounts for only 3% of the total water. Most freshwater is found in groundwater or glaciers, making the actual usable amount very limited. Furthermore, due to recent environmental pollution, climate change, and population issues, about two-thirds of the global population is experiencing water shortages, making securing water suitable for survival and consumption a critical issue.

The optimal solution to water scarcity is seawater desalination technology. However, currently commercialized desalination technologies require large-scale facilities and high costs and energy for operation, and the salt byproduct poses significant long-term operational challenges. Therefore, these technologies are unsuitable for underdeveloped countries or remote island regions facing severe water shortages.

Photo left: Schematic diagram of a material that absorbs seawater, evaporates water based on solar energy, and discharges salt
Photo right: Demonstrates that the used material can be recovered and regenerated through a simple heating and cooling process

The research team developed a seawater desalination material based on natural substances that is much simpler than existing technologies and requires no additional energy other than solar power. Made from natural materials agar and nanocellulose, the material is free from environmental issues. In particular, agar exhibits excellent water absorption, effectively transporting water inside the material while preventing salt accumulation during the desalination process through active salt discharge.

Experimental results confirmed that under sunlight conditions identical to real-world exposure, the material can produce an average of 5.95 kg of freshwater per square meter per day (up to 13.3 kg depending on solar radiation). After nine days of testing, there was no change in salt concentration inside or outside the material. Being made from natural materials, it biodegrades after disposal, posing no environmental problems, and can be recovered, regenerated, and reused. No efficiency degradation was observed after four regeneration cycles, and the material cost is only $0.27 per square meter. The manufacturing process is very simple, and the device can be produced in a compact form, suggesting the possibility of small-scale desalination facilities for households or villages.

Professor Kim said, "While developing cutting-edge materials is important, it is also essential to develop appropriate technology-based materials that are necessary for daily human life and can be easily made and used." He added, "By using very inexpensive raw materials easily obtained from nature, such as agar and cellulose, and a simple fabrication method, we developed a desalination material that can help solve drinking water problems in underdeveloped countries or remote islands."

Meanwhile, the research results were published on the 15th of last month in the international journal 'Desalination.'

This content was produced with the assistance of AI translation services.