Saline water
From Wikipedia, the free encyclopedia
Saline water is water that contains a significant concentration of dissolved salts. The concentration is usually expressed in parts per million (ppm) of salt. Sea water has a salinity of roughly 35,000 ppm, equivalent to 35 g/L. The USGS uses the following terms to classify water of different salinities:
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Fresh water < 1,000 ppm Slightly saline water 1,000 - 3,000 ppm Moderately saline water 3,000 - 10,000 ppm Highly saline water 10,000 - 35,000 ppm
Another classification for water salinity appears as follows:
| Water salinity based on dissolved salts in parts per thousand (‰) | |||
|---|---|---|---|
| Fresh water | Brackish water | Saline water | Brine |
| < 0.5 ‰ | 0.5 - 30 ‰ | 30 - 50 ‰ | > 50 ‰ |
With the scarcity of fresh water in some areas of the world, the world is taking more notice of uses for slightly saline water and methods to desalinate it. For example, in Colorado, water having up to 2,500 ppm of salt is used for irrigating crops. Normally, moderately or highly salinated is of little use to humans. Humans cannot drink salinated water, nor is it suitable for irrigating crops. Industry also rarely uses salinated water because of the effect salt water has on metal components, among other reasons.
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[edit] Saline water use
In today's world people are more aware of the need to conserve freshwater. With the ever-growing demand for water by growing populations worldwide, many people have taken it upon themselves to try to find more uses for the abundant saline water supplies that exist, mainly in the oceans. By looking at the United States water-use one can see the amounts used. About 15 percent of all water used in the United States in 2000 was saline. Almost all saline withdrawals, over 96 percent, were used by the thermoelectric-power industry to cool electricity-generating equipment. About two percent of the Nation's saline water was used for mining and industrial purposes.
[edit] Saline water use by State, United States, 2000
Due to their proximity to the Atlantic and Pacific Oceans, states on the eastern and western coasts of the United States and those States which border on the Gulf of Mexico make the most use of saline water. Almost 50% of all saline water used occurred in California, Florida, and Maryland.
[edit] Trends in saline-water use, 1950-2000
The use of saline water, and freshwater also, has been trending downward since peaking in 1980. But, in the period between 1950 and 1980, the use of saline water increased at a much higher rate than freshwater use.
[edit] References
- U.S. Geological Survey (Water Science for Schools) (http://ga.water.usgs.gov/edu/)
