This blog post examines how seawater desalination technology is tackling water scarcity and the current technical and environmental challenges it faces.
Seawater desalination is the process of converting seawater—which contains high levels of salt and dissolved substances, making it unsuitable for drinking, industrial, or agricultural use—into freshwater. Approximately 97.5% of the Earth’s water is seawater, with only the remaining 2.5% being freshwater. However, a significant portion of this 2.5% freshwater exists as ice or groundwater, making the actual water resources available for human use extremely limited. Therefore, as water scarcity intensifies, seawater desalination technology is emerging as an essential alternative.
After accounting for water loss, only about 26% of the Earth’s total water resources are available for human use. This figure is likely to decrease further due to rising water demand driven by continuous population growth and economic expansion. In this context, water-related disasters, particularly natural disasters like earthquakes and droughts, exacerbate the instability of water resources, worsening the water shortage problem. Furthermore, climate change driven by global warming is increasing rainfall variability in specific regions, leading to imbalances in water supply. This is causing water conflicts in various parts of the world, and some countries are adopting diverse strategies to secure water resources as a necessity.
If freshwater can be obtained while minimizing water loss, that would be the best solution to the water shortage problem. However, achieving this requires moving beyond existing water management practices and adopting sustainable water management alongside new technologies. Seawater desalination technology is gaining attention as one of the key methods to address these challenges. Notably, seawater desalination offers a significant advantage by utilizing the virtually limitless resource of seawater.
Among various desalination processes, distillation and reverse osmosis are the most widely used. Distillation is one of the oldest desalination technologies, used since ancient times, effectively removing impurities from water during the distillation process. However, its high energy consumption is a drawback, often making it unsuitable for large-scale desalination. Recently, hybrid technologies combining distillation and reverse osmosis are being researched to address this issue, opening the possibility of producing high-purity freshwater while improving energy efficiency.
Reverse Osmosis (RO) utilizes semipermeable membranes and osmotic pressure to remove solutes from seawater. This technology is one of the most widely used methods in modern seawater desalination processes, boasting relatively low energy costs and high efficiency. The performance of the semipermeable membrane is a critical factor determining the efficiency of seawater desalination, and its material and structure are continuously being improved with technological advancements.
The semipermeable membrane, essential in reverse osmosis, is typically called a separation membrane in desalination processes. Various materials and structures are being researched to optimize separation membrane performance. For instance, research is underway to enhance water permeability and maximize salt rejection efficiency by controlling the membrane’s surface characteristics using nanotechnology. Such technological advancements play a crucial role in improving the economic viability of desalination processes.
If biofouling issues are addressed alongside enhanced salt rejection functionality, reverse osmosis could become the most efficient and economical technology for seawater desalination. Furthermore, smart desalination systems utilizing AI and big data are now being developed. These systems analyze process data in real-time to suggest optimal operating conditions, thereby minimizing energy consumption and maximizing freshwater production. This is gaining attention as an innovative technology capable of solving water scarcity issues in the long term and points the way for future desalination technology development.
In today’s water-scarce world, desalination technology is essential and requires further development and process improvements. Seawater desalination technology will play a crucial role not only in solving water supply issues but also in adapting to climate change and building a sustainable society. To achieve this, international cooperation and technological exchange are essential, and nations must actively invest in and pursue research and development for the advancement of seawater desalination technology. Ultimately, seawater desalination technology will become a vital asset ensuring a stable water supply for our future generations.
