Brine Brine is used for food processing and cooking (pickling and brining), for de-icing of roads and other structures, and in a number of technological processes. It is also a by-product of many industrial processes, such as desalination, and may pose an environmental risk due to its corrosive and toxic effects, so it requires wastewater treatment for proper disposal. Saline water with relatively high concentration of salt (usually sodium chloride) occurs naturally on Earth's surface (salt lakes), crust, and within brine pools on ocean bottom. Numerous processes exist which can produce brines in nature. Modification of seawater via evaporation results in
Properties of water the bottom of frozen-over fresh water lakes and rivers. As the surface of salt water begins to freeze (at −1.9 °C for normal salinity seawater, 3.5%) the ice that forms is essentially salt-free, with about the same density as freshwater ice. This ice floats on the surface, and the salt that is "frozen out" adds to the salinity and density of the sea water just below it, in a process known as "brine rejection". This denser salt water sinks by convection and the replacing seawater is subject to the same process. This produces essentially freshwater ice at −1.9 °C on