Desalination: Understanding and Methods for Turning Seawater into Freshwater

The process of desalinating sea water removes the salt from the water, producing fresh water which can be used to drink or irrigate farm land. This method is useful when there are limited supplies of fresh water available.

Function

• As populations around the world grow, desalination will increasingly become a necessary method to provide people with enough fresh water to drink. Large areas of the world's population live near to a source of salt water.

Method

• A common method that is used to desalinate water on an industrial scale is called "reverse osmosis." This involves moving the water through membranes that reduce high concentrations of salt to low concentrations.

Cost

• The cost of desalinating water on a large scale may be too high. According to the U.S. Geological Survey, it can cost up to five times more than treating water from normal water sources. Future advances in technology could reduce this cost.