Seawater desalination is one of the most important ways to address global water scarcity, with reverse osmosis being the most widely used method. However, the process does present challenges, such as biofouling, and various technologies are being researched to address them. Continuous technology development is needed to make desalination more efficient and economical.
Seawater desalination is a technology that converts seawater into fresh water, which is unusable for drinking, industrial, and agricultural purposes because it contains high levels of salts and many dissolved substances. About 97.5% of the water on Earth is made up of seawater, with only 2.5% being freshwater. However, much of this fresh water is in the form of glaciers or groundwater, so the amount of water we can actually use is very limited. This makes desalination an essential alternative in the face of increasing water scarcity.
Excluding water losses, only 26% of the Earth’s water is available for human use. This figure is likely to decrease further as water use increases due to continued population growth and economic growth. Against this backdrop, water disasters, especially natural disasters such as earthquakes and droughts, are exacerbating water scarcity by destabilizing water resources. In addition, climate change due to global warming is increasing the variability of precipitation in certain regions, leading to imbalances in water supply. This has led to water conflicts in many parts of the world, and various strategies to secure water resources have become essential in some countries.
The best solution to water scarcity would be to obtain fresh water with as little water loss as possible. However, to realize this, we need to move away from conventional water management and adopt new technologies to manage water in a sustainable way. Seawater desalination technology has been recognized as one of the key ways to address this challenge. In particular, seawater desalination has the advantage of utilizing an inexhaustible resource: seawater.
Among the different desalination processes, the most popular are distillation and reverse osmosis. Distillation is one of the oldest desalination technologies, dating back to ancient times, and can effectively remove impurities from water during the distillation process. However, it is often not suitable for large-scale desalination due to its high energy consumption. Recently, hybrid technologies that combine distillation and reverse osmosis have been studied to solve this problem, opening up the possibility of producing high-purity desalinated water with greater energy efficiency.
Reverse osmosis (RO) uses a semi-permeable membrane and osmotic pressure to remove solutes from seawater. It is one of the most popular methods used in modern desalination processes, boasting relatively low energy costs and high efficiency. The performance of the membrane is an important factor in determining the efficiency of desalination, and the materials and structure of the membrane are constantly being improved as technology advances.
The reverse osmosis membrane, an essential part of the desalination process, is often referred to as the separation membrane. Different materials and structures are being investigated to optimize their performance. For example, research is underway to use nanotechnology to modify the surface properties of the membrane to increase its permeability to water and maximize salt removal efficiency. These technological advances will play an important role in improving the economics of the desalination process.
If we can improve the functionality of salt removal along with the biofouling problem, reverse osmosis will become the most efficient and economical technology for desalination. Furthermore, smart desalination systems are being developed that utilize AI and big data. These systems can analyze process data in real time to provide optimal operating conditions to minimize energy consumption and maximize freshwater production. This is attracting attention as an innovative technology that can solve the problem of water scarcity in the long term, and it shows the direction of future development of desalination technology.
In a world where water is scarce, desalination technology is essential and will require further development and process improvements. Desalination technology is not just about solving water supply, but will play an important role in adapting to climate change and building sustainable societies. International cooperation and technology exchange will be essential for this, and countries will need to actively invest and conduct research and development to advance desalination technology. Ultimately, desalination technology will be an important asset in ensuring a stable water supply for our future generations.
