Desalination of salt and seawater

As its name indicates, desalination consists of separating the salt from feedwater to obtain product water of a higher quality. Product water is often destined for human consumption (drinking water) or for other purposes, including industrial or farming activities.

SEAWATER DESALINATION PROCESS

The desalination process may be carried out using a variety of techniques, such as distillation, freezing, instant evaporation or the formation of hydrates. But reverse osmosis (RO) is currently the most efficient and effective desalination process.

Desalination by reverse osmosis of sea water (SWRO) or bore (brackish) water (BWRO) consists of pumping water at high pressure and forcing it through practically impermeable membranes that separate the salt from the water. Two different products are obtained: one that must be discarded with a high salt concentration (brine) and another with a low salt concentration, which, after being treated (remineralisation in the case of drinking water) will be converted into water for the final use.

Before the reverse osmosis process, different pre-treatment phases are employed, depending on the quality of the unprocessed water (filtering through sand, nanofiltration, microfiltration, etc) in order to prevent the delicate osmosis membranes from being damaged.