Abstract
Desalination is a practical way of making salty water drinkable and it is used widely around the world, especially in very dry countries and on ships and small islands. The process is quite expensive and it uses a lot of energy. It also produces a very concentrated waste stream of brine which has to be disposed of responsibly. For these reasons, it is generally applied as the last resource, implemented only when all other approches have failed. The most common, modern methods of desalination are thermal processes and reverse osmosis (RO). Although there is an increased trend to RO due to the advances in this technology in the last decade. Humans cannot drink seawater as it contains salt and is saline water. But, luckily saline water can be made into freshwater, so that there is enough water for drinking washing and growing crops and for everyday use. Many parts of the world such as dry desert areas simply do not have enough fresh water from surface water such as rivers, lakes. They have little rainfall and then it may only be seasonal. The scarcity of fresh water and the need for additional fresh water is already critical in many arid regions of the world and will be increasingly important in the future. It is very likely that the need for fresh water will soon be considered, in the same category as oil and energy resources, and to be one of the determining factors of world stability and the prosperity of nations. So a regular dependable supply of water is needed in these areas to enable them to have water to grow crops and build their countries to prosper. As our world populations grow we need to be able to guarantee this basic need and avoid any shortages of fresh water. The solution is to look to the abundant supply of sea water and turn salty water into fresh water for drinking.