Seawater desalination is a critical technology that converts saltwater into fresh water suitable for human consumption and industrial use. With growing global water scarcity, desalination plants have become essential infrastructure in many coastal regions, providing a reliable source of clean water.
Reverse osmosis is the most efficient and widely adopted desalination technology. The process works by applying high pressure to force seawater through specialized semi-permeable membranes. These membranes have microscopic pores that allow water molecules to pass through while blocking salt ions and other contaminants. The result is clean fresh water on one side and concentrated brine on the other.
Thermal distillation is one of the oldest desalination methods, mimicking nature's water cycle. Seawater is heated in large chambers, creating steam that rises and leaves salt and impurities behind. The steam is then cooled in condensers, turning back into pure fresh water. Modern thermal plants use multi-stage flash distillation and multi-effect distillation to improve energy efficiency.
Electrodialysis is an electrochemical separation process that uses electric current to remove salt ions from seawater. The system contains alternating ion-exchange membranes between electrodes. When electric current is applied, positive sodium ions migrate toward the negative electrode through cation-selective membranes, while negative chloride ions move toward the positive electrode through anion-selective membranes. This leaves desalinated water in the middle chambers.
Today, over 300 desalination plants operate worldwide, producing 95 million cubic meters of fresh water daily. Major facilities are found in water-scarce regions like the Middle East, Australia, and California. The future of desalination looks promising with integration of renewable energy sources, improved membrane technologies, and 50% cost reductions since 2010. As global water scarcity intensifies, desalination will become increasingly vital for sustainable water security.