Editing Brine

{{Short description|Concentrated solution of salt in water}}
{{Other uses}}
{{Water salinity}}

'''Brine''' (or '''briny water''') is a high-concentration [[Solution (chemistry)|solution]] of [[salt]] (typically [[sodium chloride]] or [[calcium chloride]]) in [[water]].  In diverse contexts, ''brine'' may refer to the salt solutions ranging from about 3.5% (a typical concentration of [[seawater]], on the lower end of that of solutions used for [[brining]] foods) up to about 26% (a typical [[saturated solution]], depending on temperature). Brine forms naturally due to [[evaporation]] of ground saline water but it is also generated in the mining of sodium chloride.<ref name=Ullmann/> 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]], so it requires [[wastewater treatment]] for proper disposal or further utilization ([[fresh water]] recovery).<ref>{{Cite journal|last1=Panagopoulos|first1=Argyris|last2=Haralambous|first2=Katherine-Joanne|last3=Loizidou|first3=Maria|date=November 2019|title=Desalination brine disposal methods and treatment technologies – A review|journal=Science of the Total Environment|volume=693|pages=133545|doi=10.1016/j.scitotenv.2019.07.351|pmid=31374511|bibcode=2019ScTEn.69333545P|s2cid=199387639}}</ref>

==In nature==
{{main|Saline water}}
[[File:Brine concentration measurement.jpg|thumb|upright|A NASA technician measures the concentration level of brine using a [[hydrometer]] at a [[salt evaporation pond]] in San Francisco.]]

Brines are produced in multiple ways in nature. Modification of seawater via evaporation results in the concentration of salts in the residual fluid, a characteristic geologic deposit called an [[evaporite]] is formed as different dissolved ions reach the saturation states of minerals, typically [[gypsum]] and [[halite]]. Dissolution of such salt deposits into water can produce brines as well. As seawater freezes, dissolved ions tend to remain in solution resulting in a fluid termed a cryogenic brine. At the time of formation, these cryogenic brines are by definition cooler than the freezing temperature of seawater and can produce a feature called a [[brinicle]] where cool brines descend, freezing the surrounding seawater.

The brine cropping out at the surface as saltwater springs are known as "licks" or "salines".<ref>{{cite web |title=The Scioto Saline-Ohio's Early Salt Industry |url=http://www.dnr.state.oh.us/Portals/10/pdf/GeoFacts/geof07.pdf |publisher=dnr.state.oh.us |url-status=dead |archive-url=https://web.archive.org/web/20121007153134/http://www.dnr.state.oh.us/Portals/10/pdf/GeoFacts/geof07.pdf |archive-date=2012-10-07 }}</ref> The contents of dissolved solids in [[groundwater]] vary highly from one location to another on Earth, both in terms of specific constituents (e.g. [[halite]], [[anhydrite]], [[carbonate]]s, [[gypsum]], [[fluoride]]-salts, [[organic halide]]s, and [[sulfate]]-salts) and regarding the concentration level. Using one of several classification of groundwater based on [[total dissolved solids]] (TDS), brine is water containing more than 100,000&nbsp;mg/L TDS.<ref>{{cite web |title=Global Overview of Saline Groundwater Occurrence and Genesis |url=http://www.igrac.net/dynamics/modules/SFIL0100/view.php?fil_Id=135 |publisher=igrac.net |access-date=2017-07-17 |archive-date=2011-07-23 |archive-url=https://web.archive.org/web/20110723153208/http://www.igrac.net/dynamics/modules/SFIL0100/view.php?fil_Id=135 |url-status=dead }}</ref> Brine is commonly produced during well completion operations, particularly after the [[hydraulic fracturing]] of a well.

==Uses==
===Iodine and bromine mining===
[[Iodine]], essential for human health, is obtained on a commercial scale from iodide-rich brines.  The purification begins by converting iodide to hydroiodic acid, which is then oxidized to iodine using chlorine.  The iodine is then separated by evaporation or adsorption.<ref>{{cite book |doi=10.1002/14356007.a14_381.pub2 |chapter=Iodine and Iodine Compounds |title=Ullmann's Encyclopedia of Industrial Chemistry |date=2015 |last1=Lyday |first1=Phyllis A. |last2=Kaiho |first2=Tatsuo |pages=1–13 |isbn=978-3-527-30673-2 }}</ref>  Bromine is also obtained from brines.  Akin to the production of iodine, the process exploits the easy oxidation of [[bromide]] into [[bromine]], again using chlorine as the oxidant.  The product bromine can be selectively collected by exploiting its volatility.<ref>{{cite book |doi=10.1002/14356007.a04_391 |chapter=Bromine |title=Ullmann's Encyclopedia of Industrial Chemistry |date=2000 |last1=Mills |first1=Jack F. |isbn=3-527-30673-0 }}</ref>

===Lithium and magnesium mining===
Major deposits of [[lithium]] are in the form of brines.<ref>{{cite book |doi=10.1002/14356007.a15_393.pub2 |chapter=Lithium and Lithium Compounds |title=Ullmann's Encyclopedia of Industrial Chemistry |date=2014 |last1=Wietelmann |first1=Ulrich |last2=Steinbild |first2=Martin |pages=1–38 |isbn=978-3-527-30385-4 }}</ref>  Magnesium is also produced in part from waste brine from various sources, such as potash production.  Crude magnesium oxides and chlorides mixtures are converted into magnesium metal by [[electrolysis]].<ref>{{cite book |doi=10.1002/14356007.a15_559 |chapter=Magnesium |title=Ullmann's Encyclopedia of Industrial Chemistry |date=2003 |last1=Amundsen |first1=Ketil |last2=Aune |first2=Terje Kr. |last3=Bakke |first3=Per |last4=Eklund |first4=Hans R. |last5=Haagensen |first5=Johanna Ö. |last6=Nicolas |first6=Carlos |last7=Rosenkilde |first7=Christian |last8=Van Den Bremt |first8=Sia |last9=Wallevik |first9=Oddmund |isbn=978-3-527-30385-4 }}</ref>

===Chlorine production===
{{main|Chlorine production}}
Elemental chlorine can be produced by [[electrolysis]] of brine ([[NaCl]] solution). This process also produces [[sodium hydroxide]] (NaOH) and [[hydrogen]] gas (H<sub>2</sub>). The reaction equations are as follows:

* Cathode: {{chem2|2 H+ + 2 e- -> H2 ↑}}
* Anode: {{chem2|2 Cl- -> Cl2 ↑ + 2 e-}}
* Overall process: {{chem2|2 NaCl + 2 H2O -> Cl2 + H2 + 2 NaOH}}

===Refrigerating fluid===<!--[[Brine (refrigerant)]] redirects here-->
Brine (primarily cheap brines based on [[calcium chloride]] and [[sodium chloride]]<ref name="Cool-Info">{{cite web |title=Secondary Refrigerant Systems |url=http://www.cool-info.co.uk/brines_steam/secondary_refrigerants/sec_refrig01.html |access-date=17 July 2017 |work=Cool-Info.com}}</ref>) is used as a secondary [[fluid]] in large refrigeration installations to transport [[thermal energy]]. It is used because the addition of salt to water lowers the freezing temperature of the solution, significantly enhancing its heat transport efficiency at low cost. The lowest freezing point obtainable for NaCl brine (called its [[eutectic]] point) is {{convert|−21.1|C}} at the concentration of 23.3% NaCl by weight.<ref name="Cool-Info" />

Because of their corrosive properties, salt-based brines have been replaced by organic liquids such as [[ethylene glycol]].<ref>{{cite web |url= http://www.accent-refrigeration.com/tips/design-tips/calcium-chloride-versus-glycol |title= Calcium Chloride versus Glycol |work= accent-refrigeration.com |access-date=17 July 2017}}</ref>

Sodium chloride brine spray is used on some fishing vessels to freeze fish.<ref name=fish>{{cite book |url= http://seafood.oregonstate.edu/.pdf%20Links/Planning-for-Seafood-Freezing.pdf |title= Planning for Seafood Freezing |first1= Edward |last1= Kolbe |first2= Donald |last2= Kramer |series= Alaska Sea Grant College Program [[Oregon State University]] |date= 2007 |isbn= 978-1566121194 |access-date= 17 July 2017 |archive-url= https://web.archive.org/web/20170712134414/http://seafood.oregonstate.edu/.pdf%20Links/Planning-for-Seafood-Freezing.pdf |archive-date= 12 July 2017 |url-status= dead }}</ref> The brine temperature is generally {{convert|-5|F|C}}. Air blast freezing temperatures are {{convert|-31|F|C}} or lower. Given the higher temperature of brine, the system efficiency over air blast freezing can be higher. High-value fish usually are frozen at much lower temperatures, below the practical temperature limit for brine.

===Water softening and purification===
Brine is used for regeneration of [[ion-exchange resin]]s.<ref>{{Cite book| title=The NALCO Water Handbook |editor-last=Kemmer |editor-first=Frank N. |publisher=McGraw-Hill |year=1979 |pages=12–7; 12–25}}</ref> After treatment, ion-exchange resin beads saturated with [[calcium]] and [[magnesium]] ions from the treated water, are regenerated by soaking in brine containing 6–12% NaCl. The [[sodium]] ions from brine replace the calcium and magnesium ions on the beads.<ref>{{cite web|url=http://www.bbc.co.uk/schools/gcsebitesize/science/triple_aqa/water/hard_soft_water/revision/4/ |title= Hard and soft water |website=GCSE Bitesize |publisher=BBC}}</ref><ref name="SenGupta2016">{{cite book|author=Arup K. SenGupta|title=Ion Exchange and Solvent Extraction: A Series of Advances|url=https://books.google.com/books?id=hf4sYJfDYm8C&pg=PA125|date= 2016|publisher=CRC Press|isbn=978-1-4398-5540-9|pages=125–}}</ref>

===Culinary===
{{main|Brining}}
Brine is a common agent in food processing and cooking. Brining is used to [[Food preservation|preserve]] or [[seasoning|season]] the food. Brining can be applied to [[vegetable]]s, [[cheese]]s, [[fruit]] and some fish in a process known as [[pickling]]. [[Meat]] and [[fish]] are typically [[steeping|steeped]] in brine for shorter periods of time, as a form of [[marination]], enhancing its [[meat tenderness|tenderness]] and [[Flavoring|flavor]], or to enhance shelf period.

===De-icing===
In lower temperatures, a brine solution can be used to [[De-icing|de-ice]] or reduce freezing temperatures on roads.<ref>{{cite web|url=http://www.usroads.com/journals/rmj/9702/rm970202.htm|title=Prewetting with Salt Brine for More Effective Roadway Deicing|website=www.usroads.com|access-date=2012-01-14|archive-url=https://web.archive.org/web/20150107172008/http://www.usroads.com/journals/rmj/9702/rm970202.htm|archive-date=2015-01-07|url-status=dead}}</ref>

===Quenching===
[[Quenching]] is a heat-treatment process when forging metals such as steel. A brine solution, along with oil and other substances, is commonly used to harden steel. When brine is used, there is an enhanced uniformity of the cooling process and heat transfer.<ref>3.	Luís H. Pizetta Zordão, Vinícius A. Oliveira, George E. Totten, Lauralice C.F. Canale, "Quenching power of aqueous salt solution", ''International Journal of Heat and Mass Transfer'', Volume 140, 2019, pp. 807–818.</ref>

== Desalination ==
The [[desalination]] process consists of the separation of [[Salt (chemistry)|salts]] from an [[aqueous solution]] to obtain [[fresh water]] from a source of [[seawater]] or [[brackish water]]; and in turn, a discharge is generated, commonly called brine.<ref>{{Cite journal |last1=Mezher |first1=Toufic |last2=Fath |first2=Hassan |last3=Abbas |first3=Zeina |last4=Khaled |first4=Arslan |date=2011-01-31 |title=Techno-economic assessment and environmental impacts of desalination technologies |url=https://www.sciencedirect.com/science/article/pii/S0011916410006296 |journal=Desalination |volume=266 |issue=1 |pages=263–273 |doi=10.1016/j.desal.2010.08.035 |bibcode=2011Desal.266..263M |issn=0011-9164}}</ref>
[[File:Brine Discharge (Iván Sola).jpg|thumb|Marine brine discharge in [[Chile]] with its surrounding [[marine life]]]]

=== Characteristics ===
The characteristics of the [[Discharge (hydrology)|discharge]] depend on different factors, such as the desalination [[technology]] used, [[salinity]] and [[Water quality|quality]] of the water used, [[Natural environment|environmental]] and [[Oceanography|oceanographic]] characteristics, desalination process carried out, among others.<ref name="Panagopoulos 111773">{{Cite journal |last1=Panagopoulos |first1=Argyris |last2=Haralambous |first2=Katherine-Joanne |date=December 2020 |title=Environmental impacts of desalination and brine treatment - Challenges and mitigation measures |url=https://doi.org/https://doi.org/10.1016/j.marpolbul.2020.111773 |journal=Marine Pollution Bulletin |volume=161 |issue=Pt B |pages=111773 |doi=10.1016/j.marpolbul.2020.111773 |pmid=33128985 |bibcode=2020MarPB.16111773P |issn=0025-326X}}</ref> The discharge of desalination plants by [[Seawater Reverse Osmosis|seawater reverse osmosis]] (SWRO), are mainly characterized by presenting a salinity concentration that can, in the worst case, double the salinity of the seawater used, and unlike of [[thermal desalination]] plants, have practically the same [[temperature]] and [[Oxygen saturation|dissolved oxygen]] as the seawater used.<ref name="Abessi 2018 259–303">{{Citation |last=Abessi |first=Ozeair |title=Brine Disposal and Management—Planning, Design, and Implementation |date=2018 |work=Sustainable Desalination Handbook |pages=259–303 |url=https://doi.org/10.1016/B978-0-12-809240-8.00007-1 |access-date=2024-04-09 |publisher=Elsevier |doi=10.1016/b978-0-12-809240-8.00007-1|isbn=978-0-12-809240-8 }}</ref><ref>{{Cite journal |last1=Mezher |first1=Toufic |last2=Fath |first2=Hassan |last3=Abbas |first3=Zeina |last4=Khaled |first4=Arslan |date=January 2011 |title=Techno-economic assessment and environmental impacts of desalination technologies |url=https://doi.org/10.1016/j.desal.2010.08.035 |journal=Desalination |volume=266 |issue=1–3 |pages=263–273 |doi=10.1016/j.desal.2010.08.035 |bibcode=2011Desal.266..263M |issn=0011-9164}}</ref>

=== Dissolved chemicals ===
The discharge could contain [[Trace element|trace chemical products]] used during the industrial treatments applies,such as [[Antiscalant|antiscalants]],<ref>{{Cite journal |last1=Chuan Yee Lee |first1=Brandon |last2=Tan |first2=Eileen |last3=Lu |first3=Yinghong |last4=Komori |first4=Hideyuki |last5=Pietsch |first5=Sara |last6=Goodlett |first6=Robb |last7=James |first7=Matt |date=2023-10-01 |title=Antiscalant and its deactivation in zero/minimized liquid discharge (ZLD/MLD) application in the mining sector – Opportunities, challenges and prospective |url=https://www.sciencedirect.com/science/article/pii/S0892687523002522 |journal=Minerals Engineering |volume=201 |pages=108238 |doi=10.1016/j.mineng.2023.108238 |bibcode=2023MiEng.20108238C |issn=0892-6875}}</ref> [[Coagulation (water treatment)|coagulants]], [[Flocculation|flocculants]] which are discarded together with the discharge, and which could affect the physical-chemical quality of the [[effluent]]. However, these are practically consumed during the process and the [[concentration]]s in the discharge are very low, which are practically [[Dilution (equation)|diluted]] during the discharge, without affecting [[marine ecosystem]]s.<ref>{{Cite journal |last1=Blanco-Murillo |first1=Fabio |last2=Marín-Guirao |first2=Lázaro |last3=Sola |first3=Iván |last4=Rodríguez-Rojas |first4=Fernanda |last5=Ruiz |first5=Juan M. |last6=Sánchez-Lizaso |first6=José Luis |last7=Sáez |first7=Claudio A. |date=November 2023 |title=Desalination brine effects beyond excess salinity: Unravelling specific stress signaling and tolerance responses in the seagrass Posidonia oceanica. |url=https://doi.org/https://doi.org/10.1016/j.chemosphere.2023.140061 |journal=Chemosphere |volume=341 |pages=140061 |doi=10.1016/j.chemosphere.2023.140061 |pmid=37689149 |bibcode=2023Chmsp.34140061B |issn=0045-6535|hdl=10045/137033 |hdl-access=free }}</ref><ref name="Fernández-Torquemada 2019 27–37">{{Cite journal |last1=Fernández-Torquemada |first1=Yolanda |last2=Carratalá |first2=Adoración |last3=Sánchez Lizaso |first3=José Luis |date=2019 |title=Impact of brine on the marine environment and how it can be reduced |url=https://doi.org/10.5004/dwt.2019.24615 |journal=Desalination and Water Treatment |volume=167 |pages=27–37 |doi=10.5004/dwt.2019.24615|bibcode=2019DWatT.167...27F |hdl=10045/101370 |hdl-access=free }}</ref>

=== Heavy metals ===
The materials used in SWRO [[Desalination plant|plants]] are dominated by [[Nonmetal|non-metallic]] components and [[stainless steel]]s, since lower operating temperatures allow the construction of desalination plants with more [[Corrosion|corrosion-resistant]] [[coating]]s.<ref>{{Cite journal |last1=Lin |first1=Yung-Chang |last2=Chang-Chien |first2=Guo-Ping |last3=Chiang |first3=Pen-Chi |last4=Chen |first4=Wei-Hsiang |last5=Lin |first5=Yuan-Chung |date=August 2013 |title=Potential impacts of discharges from seawater reverse osmosis on Taiwan marine environment |url=https://doi.org/10.1016/j.desal.2013.05.009 |journal=Desalination |volume=322 |pages=84–93 |doi=10.1016/j.desal.2013.05.009 |bibcode=2013Desal.322...84L |issn=0011-9164}}</ref><ref name="Panagopoulos 111773"/> Therefore, the [[concentration]] values of heavy metals in the discharge of SWRO plants are much lower than the acute [[toxicity]] levels to generate [[Environmental issues|environmental impacts]] on marine ecosystems.<ref>{{Citation |last1=Gheorghe |first1=Stefania |title=Metals Toxic Effects in Aquatic Ecosystems: Modulators of Water Quality |date=2017-01-18 |work=Water Quality |url=https://www.intechopen.com/chapters/52639 |access-date=2024-04-09 |publisher=IntechOpen |language=en |doi=10.5772/65744 |isbn=978-953-51-2882-3 |last2=Stoica |first2=Catalina |last3=Vasile |first3=Gabriela Geanina |last4=Nita-Lazar |first4=Mihai |last5=Stanescu |first5=Elena |last6=Lucaciu |first6=Irina Eugenia}}</ref><ref name="Panagopoulos 111773"/><ref>{{Cite journal |last1=Zhou |first1=Jin |last2=Chang |first2=Victor W.-C. |last3=Fane |first3=Anthony G. |date=January 2013 |title=An improved life cycle impact assessment (LCIA) approach for assessing aquatic eco-toxic impact of brine disposal from seawater desalination plants |url=https://doi.org/https://doi.org/10.1016/j.desal.2012.07.039 |journal=Desalination |volume=308 |pages=233–241 |doi=10.1016/j.desal.2012.07.039 |bibcode=2013Desal.308..233Z |issn=0011-9164}}</ref>

=== Discharge ===
The discharge is generally dumped back into the sea, through an underwater outfall or coastal release, due to its lower energy and economic cost compared to other discharge methods.<ref name="Fernández-Torquemada 2019 27–37"/><ref name="Missimer 198–215">{{Cite journal |last1=Missimer |first1=Thomas M. |last2=Maliva |first2=Robert G. |date=May 2018 |title=Environmental issues in seawater reverse osmosis desalination: Intakes and outfalls |journal=Desalination |volume=434 |pages=198–215 |doi=10.1016/j.desal.2017.07.012 |bibcode=2018Desal.434..198M |issn=0011-9164|doi-access=free }}</ref> Due to its increase in salinity, the discharge has a greater [[density]] compared to the surrounding seawater. Therefore, when the discharge reaches the sea, it can form a saline plume that can tends to follow the [[Bathymetry|bathymetric]] line of the bottom until it is completely diluted.<ref name="Fernández-Torquemada 137–145">{{Cite journal |last1=Fernández-Torquemada |first1=Yolanda |last2=Gónzalez-Correa |first2=José Miguel |last3=Loya |first3=Angel |last4=Ferrero |first4=Luis Miguel |last5=Díaz-Valdés |first5=Marta |last6=Sánchez-Lizaso |first6=José Luis |date=May 2009 |title=Dispersion of brine discharge from seawater reverse osmosis desalination plants |url=http://www.tandfonline.com/doi/abs/10.5004/dwt.2009.576 |journal=Desalination and Water Treatment |language=en |volume=5 |issue=1–3 |pages=137–145 |doi=10.5004/dwt.2009.576 |bibcode=2009DWatT...5..137F |hdl=10045/11309 |issn=1944-3994|hdl-access=free }}</ref><ref>{{Cite journal |last1=Loya-Fernández |first1=Ángel |last2=Ferrero-Vicente |first2=Luis Miguel |last3=Marco-Méndez |first3=Candela |last4=Martínez-García |first4=Elena |last5=Zubcoff Vallejo |first5=José Jacobo |last6=Sánchez-Lizaso |first6=José Luis |date=April 2018 |title=Quantifying the efficiency of a mono-port diffuser in the dispersion of brine discharges |url=https://doi.org/10.1016/j.desal.2017.11.014 |journal=Desalination |volume=431 |pages=27–34 |doi=10.1016/j.desal.2017.11.014 |bibcode=2018Desal.431...27L |issn=0011-9164}}</ref><ref>{{Cite journal |last1=Palomar |first1=P. |last2=Lara |first2=J.L. |last3=Losada |first3=I.J. |last4=Rodrigo |first4=M. |last5=Alvárez |first5=A. |date=March 2012 |title=Near field brine discharge modelling part 1: Analysis of commercial tools |url=https://doi.org/10.1016/j.desal.2011.11.037 |journal=Desalination |volume=290 |pages=14–27 |doi=10.1016/j.desal.2011.11.037 |bibcode=2012Desal.290...14P |issn=0011-9164}}</ref> The distribution of the salt plume may depend on different factors, such as the [[Productive capacity|production capacity]] of the plant, the discharge method, the [[Oceanography|oceanographic]] and environmental conditions of the discharge point, among others.<ref name="Abessi 2018 259–303"/><ref name="Fernández-Torquemada 137–145"/><ref name="Missimer 198–215"/><ref name="Sola 111813">{{Cite journal |last1=Sola |first1=Iván |last2=Fernández-Torquemada |first2=Yolanda |last3=Forcada |first3=Aitor |last4=Valle |first4=Carlos |last5=del Pilar-Ruso |first5=Yoana |last6=González-Correa |first6=José M. |last7=Sánchez-Lizaso |first7=José Luis |date=December 2020 |title=Sustainable desalination: Long-term monitoring of brine discharge in the marine environment |url=https://doi.org/10.1016/j.marpolbul.2020.111813 |journal=Marine Pollution Bulletin |volume=161 |issue=Pt B |pages=111813 |doi=10.1016/j.marpolbul.2020.111813 |pmid=33157504 |bibcode=2020MarPB.16111813S |hdl=10045/110110 |issn=0025-326X|hdl-access=free }}</ref>

=== Marine environment ===
Brine discharge might lead to an increase in salinity above certain threshold levels that has the potential to affect [[Benthic zone|benthic communities]], especially those more sensitive to osmotic pressure, finally having an effect on their abundance and diversity.<ref>{{Cite journal |last1=de-la-Ossa-Carretero |first1=J. A. |last2=Del-Pilar-Ruso |first2=Y. |last3=Loya-Fernández |first3=A. |last4=Ferrero-Vicente |first4=L. M. |last5=Marco-Méndez |first5=C. |last6=Martinez-Garcia |first6=E. |last7=Giménez-Casalduero |first7=F. |last8=Sánchez-Lizaso |first8=J. L. |date=2016-02-15 |title=Bioindicators as metrics for environmental monitoring of desalination plant discharges |url=https://www.sciencedirect.com/science/article/pii/S0025326X15302265 |journal=Marine Pollution Bulletin |volume=103 |issue=1 |pages=313–318 |doi=10.1016/j.marpolbul.2015.12.023 |pmid=26781455 |bibcode=2016MarPB.103..313D |issn=0025-326X}}</ref><ref>{{Cite journal |last1=Del-Pilar-Ruso |first1=Yoana |last2=Martinez-Garcia |first2=Elena |last3=Giménez-Casalduero |first3=Francisca |last4=Loya-Fernández |first4=Angel |last5=Ferrero-Vicente |first5=Luis Miguel |last6=Marco-Méndez |first6=Candela |last7=de-la-Ossa-Carretero |first7=Jose Antonio |last8=Sánchez-Lizaso |first8=José Luis |date=2015-03-01 |title=Benthic community recovery from brine impact after the implementation of mitigation measures |url=https://www.sciencedirect.com/science/article/pii/S004313541400815X |journal=Water Research |volume=70 |pages=325–336 |doi=10.1016/j.watres.2014.11.036 |pmid=25543242 |bibcode=2015WatRe..70..325D |hdl=10045/44105 |issn=0043-1354|hdl-access=free }}</ref><ref>{{Cite journal |last1=Sánchez-Lizaso |first1=José Luis |last2=Romero |first2=Javier |last3=Ruiz |first3=Juanma |last4=Gacia |first4=Esperança |last5=Buceta |first5=José Luis |last6=Invers |first6=Olga |last7=Fernández Torquemada |first7=Yolanda |last8=Mas |first8=Julio |last9=Ruiz-Mateo |first9=Antonio |last10=Manzanera |first10=Marta |date=2008-03-01 |title=Salinity tolerance of the Mediterranean seagrass Posidonia oceanica: recommendations to minimize the impact of brine discharges from desalination plants |url=https://www.sciencedirect.com/science/article/pii/S0011916407007461 |journal=Desalination |series=European Desalination Society and Center for Research and Technology Hellas (CERTH), Sani Resort 22 –25 April 2007, Halkidiki, Greece |volume=221 |issue=1 |pages=602–607 |doi=10.1016/j.desal.2007.01.119 |bibcode=2008Desal.221..602S |issn=0011-9164}}</ref>

However, if appropriate [[mitigation]] measures are applied, the potential environmental impacts of discharges from SWRO plants can be correctly minimized.<ref name="Fernández-Torquemada 2019 27–37"/><ref name="Sola 111813"/> Some examples can be found in countries such as [[Spain]], [[Israel]], [[Chile]] or [[Australia]], in which the mitigation measures adopted reduce the area affected by the discharge, guaranteeing a [[Sustainability|sustainable]] development of the desalination process without significant impacts on marine ecosystems.<ref name="Del-Pilar-Ruso 325–336">{{Cite journal |last1=Del-Pilar-Ruso |first1=Yoana |last2=Martinez-Garcia |first2=Elena |last3=Giménez-Casalduero |first3=Francisca |last4=Loya-Fernández |first4=Angel |last5=Ferrero-Vicente |first5=Luis Miguel |last6=Marco-Méndez |first6=Candela |last7=de-la-Ossa-Carretero |first7=Jose Antonio |last8=Sánchez-Lizaso |first8=José Luis |date=March 2015 |title=Benthic community recovery from brine impact after the implementation of mitigation measures |url=https://doi.org/10.1016/j.watres.2014.11.036 |journal=Water Research |volume=70 |pages=325–336 |doi=10.1016/j.watres.2014.11.036 |pmid=25543242 |bibcode=2015WatRe..70..325D |hdl=10045/44105 |issn=0043-1354|hdl-access=free }}</ref><ref>{{Cite journal |last1=Fernández-Torquemada |first1=Yolanda |last2=Carratalá |first2=Adoración |last3=Sánchez Lizaso |first3=José Luis |date=2019 |title=Impact of brine on the marine environment and how it can be reduced |url=http://www.deswater.com/DWT_abstracts/vol_167/167_2019_27.pdf |journal=Desalination and Water Treatment |volume=167 |pages=27–37 |doi=10.5004/dwt.2019.24615|bibcode=2019DWatT.167...27F |hdl=10045/101370 }}</ref><ref name="Kelaher 735–744">{{Cite journal |last1=Kelaher |first1=Brendan P. |last2=Clark |first2=Graeme F. |last3=Johnston |first3=Emma L. |last4=Coleman |first4=Melinda A. |date=2020-01-21 |title=Effect of Desalination Discharge on the Abundance and Diversity of Reef Fishes |url=https://pubs.acs.org/doi/10.1021/acs.est.9b03565 |journal=Environmental Science & Technology |language=en |volume=54 |issue=2 |pages=735–744 |doi=10.1021/acs.est.9b03565 |pmid=31849222 |bibcode=2020EnST...54..735K |issn=0013-936X}}</ref><ref>{{Cite journal |last1=Muñoz |first1=Pamela T. |last2=Rodríguez-Rojas |first2=Fernanda |last3=Celis-Plá |first3=Paula S. M. |last4=López-Marras |first4=Américo |last5=Blanco-Murillo |first5=Fabio |last6=Sola |first6=Iván |last7=Lavergne |first7=Céline |last8=Valenzuela |first8=Fernando |last9=Orrego |first9=Rodrigo |last10=Sánchez-Lizaso |first10=José Luis |last11=Sáez |first11=Claudio A. |date=2023 |title=Desalination effects on macroalgae (part b): Transplantation experiments at brine-impacted sites with Dictyota spp. from the Pacific Ocean and Mediterranean Sea |journal=Frontiers in Marine Science |volume=10 |doi=10.3389/fmars.2023.1042799 |doi-access=free |bibcode=2023FrMaS..1042799M |issn=2296-7745|hdl=10045/131985 |hdl-access=free }}</ref><ref>{{Cite journal |last1=Rodríguez-Rojas |first1=Fernanda |last2=López-Marras |first2=Américo |last3=Celis-Plá |first3=Paula S.M. |last4=Muñoz |first4=Pamela |last5=García-Bartolomei |first5=Enzo |last6=Valenzuela |first6=Fernando |last7=Orrego |first7=Rodrigo |last8=Carratalá |first8=Adoración |last9=Sánchez-Lizaso |first9=José Luis |last10=Sáez |first10=Claudio A. |date=September 2020 |title=Ecophysiological and cellular stress responses in the cosmopolitan brown macroalga Ectocarpus as biomonitoring tools for assessing desalination brine impacts |url=https://doi.org/10.1016/j.desal.2020.114527 |journal=Desalination |volume=489 |pages=114527 |doi=10.1016/j.desal.2020.114527 |bibcode=2020Desal.48914527R |issn=0011-9164}}</ref><ref name="Sola 111813"/><ref>{{Cite journal |last1=Sola |first1=Iván |last2=Zarzo |first2=Domingo |last3=Carratalá |first3=Adoración |last4=Fernández-Torquemada |first4=Yolanda |last5=de-la-Ossa-Carretero |first5=José A. |last6=Del-Pilar-Ruso |first6=Yoana |last7=Sánchez-Lizaso |first7=José Luis |date=October 2020 |title=Review of the management of brine discharges in Spain |url=https://doi.org/10.1016/j.ocecoaman.2020.105301 |journal=Ocean & Coastal Management |volume=196 |pages=105301 |doi=10.1016/j.ocecoaman.2020.105301 |bibcode=2020OCM...19605301S |issn=0964-5691}}</ref> When noticeable effects have been detected on the [[Natural environment|environment]] surrounding discharge areas, it generally corresponds to old desalination plants in which the correct [[Mitigation|mitigation measures]] were not implemented.<ref>{{Cite journal |last1=Belatoui |first1=Abdelmalek |last2=Bouabessalam |first2=Hassiba |last3=Hacene |first3=Omar Rouane |last4=de-la-Ossa-Carretero |first4=Jose Antonio |last5=Martinez-Garcia |first5=Elena |last6=Sanchez-Lizaso |first6=Jose Luis |date=2017 |title=Environmental effects of brine discharge from two desalinations plants in Algeria (South Western Mediterranean) |url=https://doi.org/10.5004/dwt.2017.20812 |journal=Desalination and Water Treatment |volume=76 |pages=311–318 |doi=10.5004/dwt.2017.20812|bibcode=2017DWatT..76..311B }}</ref><ref name="Del-Pilar-Ruso 325–336"/><ref>{{Cite journal |last1=Fernández-Torquemada |first1=Yolanda |last2=González-Correa |first2=José Miguel |last3=Sánchez-Lizaso |first3=José Luis |date=January 2013 |title=Echinoderms as indicators of brine discharge impacts |url=https://www.tandfonline.com/doi/full/10.1080/19443994.2012.716609 |journal=Desalination and Water Treatment |language=en |volume=51 |issue=1–3 |pages=567–573 |doi=10.1080/19443994.2012.716609 |bibcode=2013DWatT..51..567F |hdl=10045/27557 |issn=1944-3994|hdl-access=free }}</ref> Some examples can be found in Spain, Australia or Chile, where it has been shown that saline plumes do not exceed values of 5% with respect to the natural salinity of the sea in a [[radius]] less than 100 m from the point of discharge when proper measures are adopted.<ref name="Kelaher 735–744"/><ref name="Sola 111813"/>

=== Mitigation measures ===
The mitigation measures that are typically employed to prevent negatively impact sensitive marine environment are listed below:<ref>{{Cite journal |last1=Sola |first1=Iván |last2=Fernández-Torquemada |first2=Yolanda |last3=Forcada |first3=Aitor |last4=Valle |first4=Carlos |last5=del Pilar-Ruso |first5=Yoana |last6=González-Correa |first6=José M. |last7=Sánchez-Lizaso |first7=José Luis |date=December 2020 |title=Sustainable desalination: Long-term monitoring of brine discharge in the marine environment |url=https://doi.org/10.1016/j.marpolbul.2020.111813 |journal=Marine Pollution Bulletin |volume=161 |issue=Pt B |pages=111813 |doi=10.1016/j.marpolbul.2020.111813 |pmid=33157504 |bibcode=2020MarPB.16111813S |hdl=10045/110110 |issn=0025-326X|hdl-access=free }}</ref><ref>{{Cite journal |last1=Sola |first1=Iván |last2=Sáez |first2=Claudio A. |last3=Sánchez-Lizaso |first3=José Luis |date=November 2021 |title=Evaluating environmental and socio-economic requirements for improving desalination development |url=https://doi.org/10.1016/j.jclepro.2021.129296 |journal=Journal of Cleaner Production |volume=324 |pages=129296 |doi=10.1016/j.jclepro.2021.129296 |bibcode=2021JCPro.32429296S |issn=0959-6526|hdl=10045/118667 |hdl-access=free }}</ref><ref>{{Cite journal |last1=Sola |first1=Iván |last2=Sánchez-Lizaso |first2=José Luis |last3=Muñoz |first3=Pamela T. |last4=García-Bartolomei |first4=Enzo |last5=Sáez |first5=Claudio A. |last6=Zarzo |first6=Domingo |date=October 2019 |title=Assessment of the Requirements within the Environmental Monitoring Plans Used to Evaluate the Environmental Impacts of Desalination Plants in Chile |journal=Water |language=en |volume=11 |issue=10 |pages=2085 |doi=10.3390/w11102085 |doi-access=free |bibcode=2019Water..11.2085S |issn=2073-4441|hdl=10045/97207 |hdl-access=free }}</ref>
* A well-designed discharge mechanisms, employing the use of efficient [[Diffuser (sewage)|diffusers]] or [[Dilution (equation)|pre-dilution]] of discharges with seawater
* An [[Ecosystem valuation|environmental evaluation]] study, which assesses the correct location of the discharge point, considering [[Geomorphology|geomorphological]] and oceanographic variables, such as [[Ocean current|currents]], bathymetry, and type of bottom, which favor a rapid [[Mixing (process engineering)|mixing]] process of the discharges;
* The implementation of an adequate environmental [[surveillance]] program, which guarantees the correct operation of the desalination plants during their operational phase, allowing an accurate and early [[Diagnosis|diagnostics]] of potential environmental threats

=== Regulation ===
Currently, in many countries, such as [[Spain]], [[Israel]], [[Chile]] and [[Australia]], the development of a rigorous [[environmental impact assessment]] process is required, both for the construction and operational phases.<ref>{{Cite journal |last=Fuentes-Bargues |first=José Luis |date=August 2014 |title=Analysis of the process of environmental impact assessment for seawater desalination plants in Spain |url=https://doi.org/10.1016/j.desal.2014.05.032 |journal=Desalination |volume=347 |pages=166–174 |doi=10.1016/j.desal.2014.05.032 |bibcode=2014Desal.347..166F |issn=0011-9164}}</ref><ref>{{Citation |last1=Sadhwani Alonso |first1=J. Jaime |title=Environmental Regulations—Inland and Coastal Desalination Case Studies |date=2018 |work=Sustainable Desalination Handbook |pages=403–435 |url=https://linkinghub.elsevier.com/retrieve/pii/B9780128092408000101 |access-date=2024-04-10 |publisher=Elsevier |language=en |doi=10.1016/b978-0-12-809240-8.00010-1 |isbn=978-0-12-809240-8 |last2=Melián-Martel |first2=Noemi}}</ref><ref>{{Cite journal |last1=Sola |first1=Iván |last2=Sáez |first2=Claudio A. |last3=Sánchez-Lizaso |first3=José Luis |date=November 2021 |title=Evaluating environmental and socio-economic requirements for improving desalination development |url=https://doi.org/10.1016/j.jclepro.2021.129296 |journal=Journal of Cleaner Production |volume=324 |pages=129296 |doi=10.1016/j.jclepro.2021.129296 |bibcode=2021JCPro.32429296S |issn=0959-6526|hdl=10045/118667 |hdl-access=free }}</ref> During its development, the most important [[legal management]] tools are established within the local environmental regulation, to prevent and adopt mitigation measures that guarantee the sustainable development of desalination projects. This includes a series of administrative tools and periodic environmental monitoring, to adopt preventive, corrective and further monitoring measures of the state of the surrounding marine environment.<ref>{{Cite journal |last1=Elsaid |first1=Khaled |last2=Sayed |first2=Enas Taha |last3=Abdelkareem |first3=Mohammad Ali |last4=Baroutaji |first4=Ahmad |last5=Olabi |first5=A. G. |date=2020-10-20 |title=Environmental impact of desalination processes: Mitigation and control strategies |url=https://www.sciencedirect.com/science/article/pii/S0048969720336469 |journal=Science of the Total Environment |volume=740 |pages=140125 |doi=10.1016/j.scitotenv.2020.140125 |pmid=32927546 |bibcode=2020ScTEn.74040125E |issn=0048-9697}}</ref><ref>{{Citation |last1=Sadhwani Alonso |first1=J. Jaime |title=Chapter 10 - Environmental Regulations—Inland and Coastal Desalination Case Studies |date=2018-01-01 |work=Sustainable Desalination Handbook |pages=403–435 |editor-last=Gude |editor-first=Veera Gnaneswar |url=https://www.sciencedirect.com/science/article/pii/B9780128092408000101 |access-date=2024-04-10 |publisher=Butterworth-Heinemann |doi=10.1016/b978-0-12-809240-8.00010-1 |isbn=978-0-12-809240-8 |last2=Melián-Martel |first2=Noemi}}</ref>

Under the context of this environmental assessment process, numerous countries require compliance with an [[Environmental Monitoring Program]] (PVA), in order to evaluate the effectiveness of the preventive and corrective measures established during the environmental assessment process, and thus guarantee the operation of desalination plants without producing significant environmental impacts.<ref name=":0">{{Cite journal |last1=Sola |first1=Iván |last2=Sánchez-Lizaso |first2=José Luis |last3=Muñoz |first3=Pamela T. |last4=García-Bartolomei |first4=Enzo |last5=Sáez |first5=Claudio A. |last6=Zarzo |first6=Domingo |date=October 2019 |title=Assessment of the Requirements within the Environmental Monitoring Plans Used to Evaluate the Environmental Impacts of Desalination Plants in Chile |journal=Water |language=en |volume=11 |issue=10 |pages=2085 |doi=10.3390/w11102085 |doi-access=free |bibcode=2019Water..11.2085S |issn=2073-4441|hdl=10045/97207 |hdl-access=free }}</ref><ref name=":1">{{Cite journal |last1=Sola |first1=Iván |last2=Zarzo |first2=Domingo |last3=Sánchez-Lizaso |first3=José Luis |date=2019-12-01 |title=Evaluating environmental requirements for the management of brine discharges in Spain |url=https://www.sciencedirect.com/science/article/pii/S0011916419312111 |journal=Desalination |volume=471 |pages=114132 |doi=10.1016/j.desal.2019.114132 |bibcode=2019Desal.47114132S |hdl=10045/96149 |issn=0011-9164|hdl-access=free }}</ref> The PVAs establishes a series of mandatory requirements that are mainly related to the monitoring of discharge, using a series of measurements and [[Characterization (materials science)|characterizations]] based on physical-chemical and biological information.<ref name=":0" /><ref name=":1" /> In addition, the PVAs could also include different requirements related to monitoring the effects of seawater intake and those that may potentially be related to effects on the [[Terrestrial ecosystem|terrestrial environment]].

==Wastewater==
{{main|Industrial wastewater treatment#Brine treatment}}
Brine is a byproduct of many industrial processes, such as [[desalination]], power plant [[cooling tower]]s, [[produced water]] from oil and [[natural gas]] extraction, [[Acid mine drainage|acid mine or acid rock drainage]], [[reverse osmosis]] reject, [[Chloralkali process|chlor-alkali]] wastewater treatment, pulp and paper mill effluent, and waste streams from food and beverage processing. Along with diluted salts, it can contain residues of pretreatment and cleaning chemicals, their reaction byproducts and heavy metals due to corrosion.

Wastewater brine can pose a significant environmental hazard, both due to corrosive and sediment-forming effects of salts and toxicity of other chemicals diluted in it.<ref name=Desalitech>{{cite web |url=http://desalitech.com/7-ways-to-dispose-of-brine-waste/ |title=7 Ways to Dispose of Brine Waste |publisher=Desalitech |access-date=18 July 2017 |archive-date=27 September 2017 |archive-url=https://web.archive.org/web/20170927155806/http://desalitech.com/7-ways-to-dispose-of-brine-waste/ |url-status=dead }}</ref>

Unpolluted brine from desalination plants and cooling towers can be returned to the ocean. From the desalination process, reject brine is produced, which proposes potential damages to the marine life and habitats.<ref>5.	A. Giwa, V. Dufour, F. Al Marzooqi, M. Al Kaabi, S.W. Hasan, "Brine management methods: Recent innovations and current status", ''Desalination'', Volume 407, 2017, pp. 1–23</ref> To limit the environmental impact, it can be diluted with another stream of water, such as the outfall of a [[Sewage treatment|wastewater treatment]] or power plant. Since brine is heavier than seawater and would accumulate on the ocean bottom, it requires methods to ensure proper diffusion, such as installing underwater [[diffuser (sewage)|diffusers]] in the [[sewerage]].<ref>{{cite web|url=http://www.lenntech.com/processes/desalination/brine/general/brine-disposal.htm |title=Reverse Osmosis Desalination: Brine disposal |publisher=Lenntech |access-date=18 July 2017}}</ref> Other methods include drying in [[evaporation pond]]s, injecting to deep wells, and storing and reusing the brine for irrigation, de-icing or dust control purposes.<ref name=Desalitech/>

Technologies for treatment of polluted brine include: membrane filtration processes, such as [[reverse osmosis]] and [[forward osmosis]]; ion exchange processes such as [[electrodialysis]] or [[Ion-exchange resin|weak acid cation exchange]]; or evaporation processes, such as thermal brine concentrators and [[Crystallization#Evaporative crystallizers|crystallizers]] employing [[mechanical vapour recompression]] and steam.  New methods for membrane brine concentration, employing osmotically assisted reverse osmosis and related processes, are beginning to gain ground as part of zero liquid discharge systems (ZLD).<ref>{{cite web |title=Novel Technology for Concentration of Brine Using Membrane-Based System |url=https://www.osmotic-engineering.com/wp-content/uploads/2019/08/WT_AMBCArticle.pdf |publisher=Water Today |access-date=31 August 2019}}</ref>

==Composition and purification==
Brine consists of concentrated solution of Na<sup>+</sup> and Cl<sup>−</sup> ions.   Other cations found in various brines include K<sup>+</sup>, Mg<sup>2+</sup>, Ca<sup>2+</sup>, and Sr<sup>2+</sup>.  The latter three are problematic because they form scale and they react with soaps.  Aside from chloride, brines sometimes contain Br<sup>−</sup> and I<sup>−</sup> and, most problematically, sulfate {{chem|SO|4|2−}}.  Purification steps often include the addition of calcium oxide to precipitate solid [[magnesium hydroxide]] together with gypsum (CaSO<sub>4</sub>), which can be removed by filtration.  Further purification is achieved by [[Fractional crystallization (chemistry)|fractional crystallization]].  The resulting purified salt is called '''evaporated salt''' or '''vacuum salt'''.<ref name=Ullmann>{{Ullmann |doi=10.1002/14356007.a24_317.pub4|title=Sodium Chloride|year=2010|last1=Westphal|first1=Gisbert|last2=Kristen|first2=Gerhard|last3=Wegener|first3=Wilhelm|last4=Ambatiello|first4=Peter|last5=Geyer|first5=Helmut|last6=Epron|first6=Bernard|last7=Bonal|first7=Christian|last8=Steinhauser|first8=Georg|last9=Götzfried|first9=Franz|isbn=978-3527306732}}</ref>

==See also==
* {{annotated link|Brine mining}}
* {{annotated link|Brinicle}}
* [[Brine pool]]s – Anoxic pockets of high salinity on the [[ocean bottom]]

==References==
{{Reflist}}

{{Wastewater}}
{{Authority control}}

[[Category:Salts]]
[[Category:Coolants]]
[[Category:Refrigerants]]
[[Category:Hydrology]]
[[Category:Industrial minerals]]