Seawater desalination methods pdf

Membrane methods of desalination require energy for mechanical processes. Numerous membrane filtration seawater desalination plants are currently under construction or in the planning stages up and down californias parched coast, with the 50 million gallons per day mgd carlsbad. Desalination is a general term for the process that removes dissolved solids and. Other considerations include the degree of purity required, scale of production and cost of chemical pretreatments.

Seawater desalination has the potential to reliably produce enough potable water to support large populations located near the coast. The global challenge of sustainable seawater desalination. Several years ago, more than 00 desalination plants processed 12 billion gallons of water daily. Desalination is a relatively new science that has developed to a large extent during the latter half of the 20th century, and continues to undergo technological improvements even at the present time.

Thermal methods require a large input of energy to heat the water. Pdf desalination technologies for developing countries. In ancient times, many civilizations used this process on their ships to convert sea water into drinking water. Rightnow, desalinating seawater is the only viable way to provide water togrowing populations, and large desalination plants are now a fact oflife. Desalination of brackish water and seawater has since. Desalinationremoving dissolved minerals from seawater, brackish groundwater, or treated wastewaterappears at first glance to be the ideal answer to freshwater shortages. Membranebased seawater desalination processes have typically applied only ro. Three major seawater desalination technologies reverse osmosis 2. Distillation desalination is one of mankinds earliest forms of water treatment, and it is still a popular treatment solution throughout the world today. Until recently, in desalination treatment plants seawater was pretreated with a combination of conventional techniques such as air flotation, clarification, sand filtration and cartridge. Desalination of water has become a key to helping meet increasing water needs, especially in waterstressed countries where water obtained by desalination far exceeds supplies from the freshwater. Seawater desalination is rapidily emerging as one of the major new sources of freshwater for. Distillation is a phasechange method whereby saline water is heated to. A desalination plant turns salt water brackish or seawater into fresh water potable.