Brines

Brines are highly saline water solutions in which the dissolved salts exceed those of ordinary seawater. They range from concentrated salt solutions to hypersaline liquids containing salts such as sodium chloride, sodium sulfate, calcium chloride, and potassium compounds. Brine salinity is commonly expressed in grams per liter or practical salinity units; seawater averages about 35 g/L.

Brines occur naturally and commercially. Natural brines form in evaporative environments such as salt lakes, playas, and underground aquifers where prolonged evaporation concentrates salts. Hypersaline brines may also occur in oil and gas reservoirs. Industrial brines arise as by-products or concentrates from processes like desalination, potash and other salt production, chlor-alkali production, and mining operations. Their composition can vary widely depending on source and processing.

Uses of brines include de-icing roads, food processing and preservation (brining meat and vegetables), water treatment, and various industrial applications. In the oil and gas sector, produced water and formation brines are used in drilling fluids and, in some cases, enhanced oil recovery. Brine management is an important environmental issue because improper disposal or discharge can raise salinity in soil and water, affecting ecosystems.

Treatment and management methods include dilution, evaporation ponds, and crystallization to recover and recycle salts, as well as zero-liquid-discharge systems. Depending on source, treatment may target metals, boron, organics, and other contaminants to reduce environmental impact. Safety considerations note that high-salinity solutions can be corrosive and hazardous to aquatic life if released untreated.