Desalination Methods

Owing to the large amount of dissolved salts in sea water, it is necessary to purify it before using it for any purpose, be it domestic purposes or drinking. Desalination is the process in which dissolved salts and minerals are removed form sea/ocean water by using various techniques. These techniques have developed over the years. Different techniques have different perks and the best one is chosen according to its energy efficiency.

Various changes govern the usage of desalination techniques, such as the changes in climate, increase in population, urbanisation, and so on. It is necessary to adapt to these changes and accordingly develop newer desalination methods. Another factor to take in consideration while choosing a desalination technique is the amount of water wasted. In a world where water scarcity is already a major problem, smart decisions have to be taken so as to not let any water go waste.

The different methods used for desalination of water are:

THERMAL DESALINATION:

Thermal desalination is the process of boiling the seawater, condensing the vapour and getting purified water. The benefit of this method is that pure water is obtained no matter how much water is put in the heater and no matter how much salt is contained in it. But, this process consumes a lot of energy, requires huge apparatus and produces a lot of poisonous brine waste. It is best to use this process for highly saline water, like ocean water, because the energy requirement is the same regardless of the amount of salt dissolved in it.

This process consumes about 80 megawatt-hours per mega-litres of water. This process is mainly used in the Middle East, where the purification plants use wasted heat generated in nearby plants and cheap oil in place of