Water Desalination

*Outline

*What is desalination?*Why desalination?*Types of desalination.*Steps of desalination.*Desalination in Saudi Arabia.*Problems.*Research and development.

*What is desalination?*Desalination is the process of removing salt from

seawater.

*What is desalination?

*Desalination was first used by Greek sailors in the 4th century BC to evaporate seawater and create drinking water. Today there are two main desalination technologies – membrane (RO) and thermal desalination.

* Why desalination?

*71% of the earth surface is covered by water.

*Why desalination?*98% of that water is oceans.*Only 2% is available for drinking.*80 countries from water scarcity by the mid-1990s

*Types of desalination

*Reverse Osmosis (RO): desalination uses the principle of osmosis to remove salt and other impurities, by transferring water through a series of semi-permeable membranes.

*Types of desalination

*Thermal: desalination uses heat, often waste heat from power plants or refineries, to evaporate and condense water to purify it. In the most advanced desalination plants, such as those built by IDE, water is pretreated in order to improve the efficiency of the plants.

Steps of desalination

*Desalination in Saudi Arabia*The single largest desalination project

is “Ras Al-Khair” in Saudi Arabia, which produced 1,025,000 cubic meters per day in 2014.

*The largest percent of desalinated water used in any country is in Israel, which produces 40% of its domestic water use from seawater desalination.

*Water desalination consumes a huge amount of energy that obtained by burning fuel or using electric energy or nuclear energy , and thus raise the Carbon dioxide or the complications of nuclear leakage.*Also of the environmental problems is the remnants of the desalination process , which increases when delivering into the sea the amount of dissolved salts in it , and this has a negative effect on the marine life.*Increasing chemicals that used in desalination process cause disease in the long term.

Problems

* Research and development

*In research centers around the world made a research on the following topics:*Find the current methods for the desalination process alternatives: through finding new membranes are better than the current in the process of separating salts and choose the appropriate chemical and operational factors.

*Research and development

*Find chemical additives for polymer material alternatives: through the use of genetic engineering to accelerate the water purification and treatment process using microorganisms*Find alternatives to energy used for the desalination process: through the use of renewable energy such as solar or wind power, or the waves of the sea card