Desalination

Desalination is a process that removes minerals from saline water (sea water). This is usually done by passing sea water through a bank of special membranes that separate the salt out into a concentrated steam and returned to sea. The pure water is collected and used for potable water.

Salt water is desalinated to produce fresh water suitable for human consumption or irrigation. 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.
Desalination is particularly relevant in dry countries such as Oman and the other GCC counties, which traditionally have relied on collecting ancient rainfall from aquafers deep underground to provide their drinking water supplies.

By nature most of the desalination plants are located on the sea shore in order that the ‘purest’ sea water be drawn into the plants for processing. This usually involves a long HDPE intake pipe going out into the deeper water to drawn in water free from sand and debris. Additionally, a twin HDPE pipe returns the, now salt concentrated, reject back sea water off-shore where it will not cause harm to sea life due to the heavy salt concentration.

According to the International Desalination Association, approximately 16,000 desalination plants operated worldwide, producing 675 million cubic meters per day, providing water for 300 million people.