In today’s fast pace environmental and technological changing world, the water purity is a challenge for human being. However, water desalination system is the best solution that has completely solved the problem. Water desalination is basically a process of removing salts from seawater to formulate it suitable for irrigation, industrial utilization and finally human utilization for drinking and other daily use.
Water desalination have progressively more been used through the globe to make the quality of fresh water for drinking and industrial use and further also used to treat industrial wastewater prior to discharge (so it would not harm the environmental purity) or reuse (for industrial reuse). At the moment, approximately 4000 desalination plants are under working in 120 countries worldwide with a combined capacity of 3,500 million gallons per day (mgd).
The changing world is also expecting continuous growth in water desalination technology because increasing shortage of usable surface and ground water in many parts of the world, and finally large-scale water desalination will only be the cost effective as a last choice when time comes. The principal purpose of water desalination is to make safe and harmless drinking water and industrial water from seawater and brackish ground water, since water contamination is the major become today, and it has to be improved by removing harmful substances likewise trihalomethane, nitrogen, phosphorous and organic carbons etc.
Process of Water Desalination The process of desalination is mainly comprises on two stages. In the first stage, water filtered by using sand or an “ultra filtration” membrane, which is a little like strainer with very small holes. This method remove solid particles and bacteria from water and will be evaluated in the pilot plant.
In the second stage, water forced through an incredible fine semi-permeable membrane (another strainer with much even smaller holes) at high pressure and it removes all the dissolved salts and other pollutants (This second Membrane processes can either be pressure-driven (reverse osmosis) which is now the most common method, or it could be voltage-driven (electro-dialysis), and the final result we get is the pure and clean water.
The above picture of seawater desalination depicts that the physical principle of osmosis allows the best least concentrated solution (soft water) to migrate naturally towards the most concentrated solution (sea water) to dilute it. In order to desalinate, the direction of the water flow is reversed by applying pressure on the concentrated solution. The membrane than allows water molecules through but in this new direction, holds back the salts and pollutants (organic materials, viruses, bacteria).Sample Essay of Essayontime.com