Water Desalination Using Renewable Solar Energy

Water is one of the earth?s most abundant resources, covering about three- quarters of the planet?s surface. Plenty of water sources are available on the earth but only 3% of water on the surface is fresh; the remaining 97% resides in the ocean. Of freshwater, 69% resides in gla1ciers, 30% underground, and less than 1% is located in lakes, rivers and swamps. Looked at another way, only 1% of the water on the surface is usable by humans, and 99% of usable quantity is situated underground. Only 1% of the water is in a fresh, liquid state, and nearly all of this is polluted by both pathogens and toxic chemicals.Tackling the water scarcity problem must involve better and more economic ways of desalinating seawater. This article presents a comprehensive review of water desalination systems, whether operated conventional energy or renewable energy, to convert saline water into fresh water. These systems comprise the thermal phase change and membrane processes, in addition to some alternative processes. Thermal processes include the multistage flash, multiple effects boiling and vapors compression, co generation and solar distillation, while the membrane processes include reverse osmosis, electrodialysis and membrane distillation. It also covers the integration into desalination systems of potential renewable energy resources, including solar energy etc. Such systems are increasingly attractive in such areas suffering of fresh water but where solar energy is plentiful.