Salt is removed from seawater by different varieties of two basic processes: distillation, which is also referred to as "thermal," and reverse osmosis, which is also called "membrane." Distillation involves boiling seawater until it evaporates, leaving the salt behind, and then allowing the water vapor to condense and collect elsewhere. Reverse osmosis uses pressure to force seawater against a specialized filter or semipermeable membrane with openings too small to allow the dissolved salt to pass through.Continue Reading
The distillation processes used for desalination include the multi-stage flash method, multi-effect distillation and vapor compression distillation. Membrane processes include reverse osmosis, electrodialysis and electrodialysis reversal. Multi-stage flash distillation and reverse osmosis account for the majority of the desalination plant methods in use worldwide. The world's largest desalination plant, an integrated power and water facility, is in Saudi Arabia. The largest portion of a domestic water supply produced by seawater desalination, at about 40 percent, is in Israel.
Both the distillation and reverse osmosis desalination methods are expensive. A great deal of electrical power is used, with distillation ranking as the greater energy consumer. Cogeneration is a possible solution to the cost issue which applies the excess heat produced by an electrical power plant to an additional process, such as desalination, in a dual-purpose facility. The majority of cogeneration power plants producing potable water from seawater are in North Africa or in the Middle East where abundant petroleum reserves help offset the limited accessibility of drinking water.Learn more about Chemistry
Installing a reverse osmosis, ultrafiltration, distillation or ion exchange system is the most effective method to remove arsenic from well water. Typically these types of systems treat only one faucet in a house. Boiling water or chemically disinfecting it with a treatment, such as chlorine, does not remove arsenic.Full Answer >
Water filters work by disinfection methods, filtration, reverse osmosis, distillation and ion exchange to remove harmful impurities. Each process has its advantages and kills specific types of contaminates. Disinfection methods include using choline, boiling and pasteurization to kill bacteria that cause acute illness, and carbon filtration systems sift out sand, silt, clay and other organic material that has been suspended in the water, as noted by the University of Missouri Extension.Full Answer >
The most effective way to remove fluoride from the water at home is with a reverse osmosis filter. To make a portable reverse osmosis filtration system, buy a filter set, install it under your sink and flush the filter with water. Making a fluoride filter takes roughly 30 minutes and requires a reverse osmosis filter set and needle nose pliers. You may need a drill, an adaptor and gaskets for your faucet.Full Answer >
The most commonly observed real life example of osmosis is the pruning of the fingers when they are immersed in water for a lengthy period of time. Other easily observable examples of osmosis include soaking dehydrated fruit and vegetables until they expand, or watching a freshly watered plant absorb water through the soil.Full Answer >