Sea Water Treatment
Together with the growing population on the planet, there is an increasing demand on water supplies. In some countries , there are already insufficient freshwater resources to supply residents, industry and agriculture. These areas are dependent primarily on the use of the salt water. Salty sea water contains large amounts of dissolved substances, reaching concentrations up to 37 000 mg/l and because of such a high concentrations, it is not suitable for further use. With the use of the membrane processes, it is possible to remove the solubles and enable its further use as a drinking water, in the industry, or in agriculture. The most suitable method to desalinate the sea water is the reverse osmosis, which provides a highest efficiency in relation to energy consumption.
There is a vast amount of water on the Planet, but only the less than one thousandth of a percent is fresh water in a liquid form. Almost 98 percent of water is in the oceans and the seas - the salt water. Because of its high level of dissolved solids, the sea water is quite unsuitable for consumption or for another, eg. industrial use.
If the water contains more than 2000 mg/l of dissolved solids, it is referred to as a salty water and therefore unsuitable for drinking. The average content of dissolved solids in the sea water ranges between 33 000 to 37 000 mg/l. If such a water has to be suitable for drinking, it would be necessary to decrease the dissolved solids content to less than 1000 mg/l (such water is already known as edible), or preferably to a value of about 500 mg/l.
There is a number of possibilities to reduce the amount of dissolved solids in the salt water. Decreasing of the dissolved salts content is generally called as desalination and the process mostly used for the salt water desalination is the membrane technology.