Bromate: Difference between revisions

{{Short description|Ion, and compounds containing the ion}}

{{Redirect|Bromates|the 2022 buddy comedy film|Bromates (film)}}

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid = 459983083

| ImageSize =

| ImageAlt =

| IUPACName =

| PIN =

| OtherNames =

|Section1={{Chembox Identifiers

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo = 15541-45-4

| PubChem = 84979

| ChEMBL_Ref = {{ebicite|changed|EBI}}

| ChEBI_Ref = {{ebicite|correct|EBI}}

| Gmelin = 1888

| UNNumber = 1450

| SMILES = [O-] [Br+2]([O-])[O-]

}}

|Section2={{Chembox Properties

| Formula = {{chem|BrO|3|-}}

| MolarMass =

| Appearance =

| Density =

| MeltingPt =

| BoilingPt =

| Solubility =

| ConjugateAcid = [[Bromic acid]]}}

|Section3={{Chembox Hazards

| MainHazards =

| FlashPt =

| AutoignitionPt = }}

The '''bromate''' [[ion|anion]], BrO{{su|b=3|p=−}}, is a [[bromine]]-based [[oxyanion|oxoanion]]. A '''bromate''' is a [[chemical compound]] that contains this ion. Examples of bromates include [[sodium bromate]] ({{chem|NaBrO|3}}) and [[potassium bromate]] ({{chem|KBrO|3}}).

Bromates are formed many different ways in municipal drinking water. The most common is the reaction of [[ozone]] and [[bromide]]:

Electrochemical processes, such as [[chloralkali process|electrolysis of brine without a membrane]] operating to form [[hypochlorite]], will also produce bromate when bromide ion is present in the brine solution.

[[Photoactivation]] (sunlight exposure) will encourage liquid or gaseous bromine to generate bromate in bromide-containing water.

In laboratories bromates can be synthesized by dissolving {{chem|Br|2}} in a concentrated solution of [[potassium hydroxide]] (KOH). The following reactions will take place (via the intermediate creation of [[hypobromite]]):

== Human health issues ==

Bromate in drinking water is toxic because it is a suspected human [[carcinogen]].<ref>{{cite web

| url= http://www.inchem.org/documents/iarc/vol73/73-17.html

| work= [[International Agency for Research on Cancer]]: Summaries and Evaluations

| title= Potassium Bromate (Group 2B)

| publisher= [[Canadian Centre for Occupational Health and Safety]]

| accessdate= 2008-03-09

| pmc=1567851

| title= Toxicity and carcinogenicity of potassium bromate—a new renal carcinogen

| journal= [[Environmental Health Perspectives]]

| date=July 1990

| volume= 87

| pages= 309–35

| doi= 10.1289/EHP.9087309

| last1= Kurokawa|first1= Yuji

| pmid= 2269236

| last2=Maekawa

| first2=A

| last3=Takahashi

| first3=M

| last4=Hayashi

| first4=Y

| jstor=3431039

}}</ref><!-- The only organisms that developed tumors with potassium bromate, also developed tumors with potassium carbonate. Sodium bromate has not been observed to produced tumors in organisms, and it has been extensively tested --> Its presence in Coca-Cola's [[Dasani]] bottled water forced a recall of that product in the [[UK]].<ref>{{cite news

| url= http://news.bbc.co.uk/1/hi/business/3550063.stm

| title= Coke recalls controversial water

| work= [[BBC News]]

| date= 2004-03-19

| accessdate= 2008-03-09

}}</ref>

== Bromate formation during ozonation ==

Although few by-products are formed by ozonation, ozone reacts with bromide ions in water to produce bromate. Bromide can be found in sufficient concentrations in fresh water to produce (after ozonation) more than 10 ppb of bromate—the maximum contaminant level established by the USEPA. Proposals to reduce bromate formation include: lowering the water pH below 6.0, limiting the doses of ozone, using an alternate water source with a lower bromide concentration, pretreatment with ammonia, and addition of small concentrations of chloramines prior to ozonation.<ref>{{Cite journal|doi = 10.1002/j.1551-8833.2004.tb10542.x|title = Controlling Bromate Formation: During Ozonation with Chlorine and Ammonia|journal = Journal - American Water Works Association|volume = 96|issue = 2|pages = 26–28|year = 2004|last1 = Neemann|first1 = Jeff|last2 = Hulsey|first2 = Robert|last3 = Rexing|first3 = David|last4 = Wert|first4 = Eric| s2cid=94346527 }}</ref>

== Reservoir pollution ==

[[File:Ivanhoe Reservoir looking northeast from west side 2015-10-11.jpg|thumb|Ivanhoe Reservoir after addition of shade balls]]

On December 14, 2007, the [[Los Angeles Department of Water and Power]] (LADWP) announced that it would drain [[Silver Lake Reservoir]] and Elysian Reservoir due to bromate contamination. At the Silver Lake and Elysian reservoirs a combination of bromide from well water, chlorine, and sunlight had formed bromate. The decontamination took 4 months, discharging over {{convert|600|e6USgal|e6m3}} of contaminated water.<ref>{{cite news

| url= http://www.knbc.com/news/14858647/detail.html

| title= DWP To Drain 2 Reservoirs After Potentially Harmful Chemical Found

| date= 2007-12-14

| work= [[KNBC]] News

| accessdate= 2008-03-09

}}{{Dead link|date=July 2020 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

On June 9, 2008 the LADWP began covering the surface of the {{convert|10|acre|adj=on|0}}, {{convert|58|e6USgal|e6m3|adj=on}} open Ivanhoe Reservoir with black, plastic [[shade balls]] to block the sunlight which causes the naturally present bromide to react with the chlorine used in treatment. 3 million of the 40 cent balls are required to cover the Ivanhoe and Elysian reservoirs.<ref>{{cite news|url=http://www.latimes.com/news/local/la-me-balls10-2008jun10,0,5878575.story|title=DWP drops 400,000 balls onto Ivanhoe Reservoir|work=Los Angeles Times|first=Francisco|last=Vara-Orta|date=2008-06-10|access-date=2008-06-10|archive-date=2008-10-07|archive-url=https://web.archive.org/web/20081007230511/http://www.latimes.com/news/local/la-me-balls10-2008jun10,0,5878575.story|url-status=dead}}</ref>

== Natural occurrence ==

Currently no bromate-bearing minerals (i.e., the ones with bromate ion being an essential constituent) are known.<ref>{{Cite web|url=https://www.mindat.org/|title=Mindat.org - Mines, Minerals and More|website=www.mindat.org}}</ref>

==See also==

Other bromine anions:

{| class="wikitable"

|-

! Bromine oxidation state

| −1

| +1

| +3

| +5

| +7

|-

! Name

| [[bromide]]

| [[hypobromite]]

| [[bromite]]

| '''bromate'''

| [[perbromate]]

|-

! Formula

| Br⁻

| BrO⁻

| {{chem|BrO|2|−}}

| {{chem|BrO|3|−}}

| {{chem|BrO|4|−}}

|-

! Structure

| [[File:Bromide ion.svg|50px|The bromide ion]]

| [[File:Hypobromite ion Space Fill.png|50px|The hypobromite ion]]

| [[File:Bromite-ion-from-xtal-1989-Mercury-3D-sf.png|50px|The bromite ion]]

| [[File:Bromate-3D-vdW.png|50px|The bromate ion]]

| [[File:Perbromate-3D-vdW.png|50px|The perbromate ion]]

|}

== References ==

{{Bromates}}