Desalination, desalinization, and desalinisation refer to any of several processes that remove some amount of salt and other minerals from saline water. More generally, desalination may also refer to the removal of salts and minerals, as in soil desalination, which also happens to be a major issue for agricultural production.
Salt water is desalinated to produce fresh water suitable for human consumption or irrigation. One potential byproduct of desalination is salt. Desalination is used on many seagoing ships and submarines. Most of the modern interest in desalination is focused on developing cost-effective ways of providing fresh water for human use. Along with recycled wastewater, this is one of the few rainfall-independent water sources.
Due to relatively high energy consumption, the costs of desalinating sea water are generally higher than the alternatives (fresh water from rivers or groundwater, water recycling and water conservation), but alternatives are not always available and rapid overdraw and depletion of reserves is a critical problem worldwide. Quoting Christopher Gasson of Global Water Intelligence, At the moment, around 1% of the world’s population are dependent on desalinated water to meet their daily needs, but by 2025, the UN expects 14% of the world’s population to be encountering water scarcity. Unless people get radically better at water conservation, the desalination industry has a very strong future indeed.
Desalination is particularly relevant to dry countries such as Australia, which traditionally have relied on collecting rainfall behind dams to provide their drinking water supplies. According to the International Desalination Association, in June 2011, 15,988 desalination plants operated worldwide, producing 66.5 million cubic meters per day, providing water for 300 million people. This number has been updated to 78.4 million cubic meters by 2013., or 57% greater than just 5 years prior. The single largest desalination project is Ras Al Khair in Saudi Arabia, which produces 1,025,000 cubic meters per day in 2014 The largest percent of desalinated water used in any country is in Israel, which produces 40% of its domestic water use from seawater desalination.