What is Desalination?
Desalination is a process of removing salt usually involving waters from the sea. But this process can also be done using brackish water and/or waste water for the purpose of producing water suitable for consumption by human beings.
Much of the water available in this planet comes from the oceans. Only a small percentage of water comes from river or lake sources. A large part of freshwater sources are not readily available because they are frozen. This is why desalination has been employed by many countries to provide enough drinking water supply to the world’s ever-growing population.
There are three commonly employed desalination processes. One such process is through Electro-dialysis or Electro-dialysis Reversal. In electro-dialysis, an electric volt is applied to specific membranes that allow the passage of either positive or negative ions. Through this process, water’s impurities are separated into different container-like cells, with one container dedicated to the “cleaned” water. Electro-dialysis Reversal meanwhile uses the same membrane technology but has its own cleaning features. This reversal technique is said to have higher yields and longer life for the membranes.
Another common desalination process is Reverse Osmosis. It involves a solvent passing through a semi-permeable membrane; meaning this particular membrane only allows some molecules to penetrate or pass through. The solvent will then go into a solution with higher concentration of molecules. A pressure is then applied to reverse the flow of the solvent, producing fresh water along the way.
Distillation is another common method wherein water that’s heated goes through several stages of lowering pressures. Vapor will then result along the way, as pressures are lowered. The resulting vapor is then collected to become fresh water.
Choosing the process of desalination may depend on the water source, cost of the entire process, scale of water production, or the degree of water purity intended.