Talk:Activated carbon

feeding of activated carbon is published at several peer reviewed papers at increasing longevity

Biomater Artif Cells Artif Organs. 1989 volume 17(3) pages 341-5

Effect of enterosorption on animal lifespan. describes feeding rats activated carbon 

Enterosorption resulted in the increase of mean and maximal lifespan by 43 and 34% respectively further studies where the number of rats was 155 (n=155) The 16-month treatment of enterosorption with an active nitrogen-containing carbon employed on 155 Vistar rats led to an AL and ML increase of 35.7 and 36.8%, respectively , and, further, to an increase in spontaneous motor activity and muscle working capacity

I bring this up here as it is peer reviewed research. There are actually three studies where activated carbon causes longer mammal lifespan. They are reviewed at Enterosorption as a Method for Prolonging Life A. V. Mamai and V. N. Kroutko at the journal Human Physiology, Vol. 22. № 3. 1996, P. 380-384. Translated from Fiziologiya Cheloveka, Vol. 22, № 3, 1996. P. 131-135

another possibly related study notes that buckminsterfullerene C60 actually doubles rat longevity.

Arsenic

I heard on the radio that some charcoal based filters introduce arsenic in the water they are supposed to purify. Is this true? Can someone comment in details? —Preceding unsigned comment added by 98.82.154.12 (talk) 03:14, 16 June 2010 (UTC)

Need image from electron microscope

The article says, "Under an electron microscope, the high surface-area structures of activated carbon are revealed. Individual particles are intensely convoluted and display various kinds of porosity". Sure would be nice if an image of this could be added to the article! 71.219.225.102 (talk) 18:42, 24 October 2009 (UTC)

Methods of preparation of activated carbon

The two broad processes by which we can make activated carbon area physical and chemical activation, not steam and chemical activation, actually steam activation is part of it. I found it wrong so correcting this now, beside this i am adding some more details about the two processes. In case anyone have some questions then please discuss. Regards---SUHAS

I stumbled over the term "aBsorption" in this article in the last sentence of the first paragraph. Unless I'm very much mistaken, this should be "aDsorption", shouldn't it ? I'd appreciate some comments on this before we change it. Regards, Fkoenig 17:50, 2 June 2006 (UTC)

Carbon!

Old encyclopedias mention "bone black" on this topic...maybe that phrase should appear somewhere...

User:Polyparadigm

It appears that bone black is slightly different than the processed activated carbon.

Why do we have that second link on the page? It appears to have nothing to do with carbon, other than that the students applying for the internship/grant money might use it...

-- ~ender 19:09:MST

I was reading that charcoal is made first and then activated. neffk (talk) 15:45, 1 July 2009 (UTC)

Incomprehensible

"Tests of adsorption behaviour are usually done with nitrogen gas at 77 K under high vacuum, but in everyday terms activated carbon is perfectly capable of producing the equivalent, by adsorption from its environment, liquid water from steam at 100 °C and a pressure of 1/10,000 of an atmosphere." Seems unintelligible to me. Does it mean that adsorption tests are done with both nitrogen gas and activated carbon? If so, what is the role of liquid water in such a prosedure, and the meaning of pressure? Should the quoted content be simplified, explained, divided to multiple parts or what? 193.166.173.23 13:55, 1 Jun 2005 (UTC)

Ok, I think I got it. Adsorpion can be tested either with gas or steam. They way it's told is really tricky tho. 193.166.173.23 16:53, 1 Jun 2005 (UTC)

Mechanism of adsorption

What is the chemical mechanism by which adsorption occurs? Charge, hydrophobicity, hydrogen bonding, etc.? Could be explained in more detail.

London dispersion force linking Done.

=> actually, it's physical mechanism, not chemical

Clean up?

It strikes me that the following words are subjective, confusing and too casual for an encyclopedia. (from anon march 1 2006)

"...with a few wood chips thrown in for good measure. There are a great number of nooks and crannies..."

Thank you for your suggestion! When you feel an article needs improvement, please feel free to make whatever changes you feel are needed. Wikipedia is a wiki, so anyone can edit almost any article by simply following the Edit this page link at the top. You don't even need to log in! (Although there are some reasons why you might like to…) The Wikipedia community encourages you to be bold. Don't worry too much about making honest mistakes—they're likely to be found and corrected quickly. If you're not sure how editing works, check out how to edit a page, or use the sandbox to try out your editing skills. New contributors are always welcome. --Arcadian 14:19, 1 March 2006 (UTC)

Agreed that the wording is not objective enough. I have also deleted the comment that it resembles ribbons of paper, because activated charcoal under the microscope can in fact look quite different depending on source, processing etc. Corrections made.Jimjamjak (talk) 13:29, 24 July 2008 (UTC)

I also removed the section allegedly relating to "traditional medicine".Jimjamjak (talk) 13:43, 24 July 2008 (UTC)

Alcohols

"Alcohol (such as ethanol, methanol, isopropyl alcohol, glycols, and acetone)" - acetone is not an alcohol

Oh but it is. See Enol.:) GreatMizuti 12:06, 3 September 2006 (UTC)

Desorption and recovery

It seems there are methods to recover adsorbed material from activated carbon, but I can't find any information on methods of doing so. If anyone has access to such information, adding it to the article would be welcome. --Six.oh.six 16:45, 10 May 2006 (UTC)

The method of recovering the absorbed material depends on what it is; the material must be driven from the activated carbon, and then collected. Methods of doing so will depend on the properties of the absorbed substance and its affinity for activated carbon. Methods of collecting it will depend, again, on its properties; gases such as nitrogen would need to be condensed at cryogenic temperatures. (203.84.132.206 (talk) 06:36, 22 January 2013 (UTC))

Applications

It's used in a hangover cure sold in Ireland.

http://www.getalifeline.com http://www.rte.ie/health/2005/0708/health1054118.html

I've used it a few times because it was free but don't know for sure if it's effective because I'm pretty random with my hangovers anyway. Could someone who knows wikipedia standards maybe add a line about it.

Cleaning of activated carbon

In the water purification process,there is a wash back step to clean up. This step normally using water. Is there any effect to the activated carbon use in the column by using alkali solution? How about acid solution? Will carbon become less effective and brittle?

Thanks

Vodka

Wasn't this debunked on Mythbusters? As I recall, professional taster was unable to discern any difference in the quality of charcoal filtered vodka. I trust them much more the reference given for this section. Gorman 11:46, 26 November 2006 (UTC)

The expert put them in perfect order, worst was control, up to 6 passes then top shelf, he even said it wont make it perfect but it does make it better. They considered it a bust because to make it as good as the top self you would need to spend more on brita filters then just buying the good stuff! Wolfmankurd 21:21, 1 June 2007 (UTC)

I hate to say it but Mythbusters is not reliable science. Good spirits are almost always passed through activated carbon to remove impurities. Nitrates can be removed using this method if I'm not mistaken. —Preceding unsigned comment added by 129.133.142.224 (talk) 00:06, 3 September 2007 (UTC)

Does anyone remember Rick's Spiked Lemonade? There's an old rumor it was made from lemon flavored and sweetened vodka. There's also a rumor that Mike's Hard Lemonade is a malt beverage (i.e. beer) that has gone through so much activated carbon that the beer flavor and color is removed so lemon-flavor and sugars can make it taste completely different. If someone can verify, that's more useful than the Vodka section. —Preceding unsigned comment added by Dagordon01 (talk • contribs) 21:11, 15 October 2007 (UTC)

Surface Area

If we're talking about surface area on a microscopic level, wouldn't a tennis court have a much higher surface area than given here in that case? Maybe this should be clarified as "a microscopically perfectly smooth surface the size of a tennis court" or something to that effect.

Carborabbi

What do observing jews use instead of carbo activatus tablets to treat diarrhea? If I understand correctly, actived carbon pills for medical use are manufactured via controlled burning of animal blood, a "dirty" substance whose ingestion is banned according to Moses' Law. This ban was overturned for christians (as described in the Acts of the Apostles), but not for religious jews. 82.131.210.162 16:22, 15 August 2007 (UTC)

Bum bum. If observing jews were so well-informed about reality—and practical enough to consider using activated charcoal in the first place, well then maybe they wouldn't be so observing. --IO Device (talk) 05:57, 19 March 2009 (UTC)

Less of it, less of it. From what I've heard, observing Jews actually tend to be pretty beady about these points. Reminds me of a story I once heard about a rabbi who was compiling an official list of which branded products were kosher-suitable, and wrote to a Chinese manufacturer only to receive the helpful reply "This product contains no kosher."  :-) As for the original point, I can't find any reference to activated charcoal tablets being made from blood. All the references I can find say it's made from wood like any other activated charcoal product. According to the "Charcoal" article, animal-derived "charcoal" has a quite different chemical composition to vegetable charcoal anyway. Wombat140 (talk) 16:50, 13 March 2014 (UTC)

Examples of adsorption SECTION

is there any DIRECT connection between this section and the activated carbon??

I dont think so, they dont even name AC! Why dont we remove it ?

It seems more appropriation under the separate wikipedia article "adsorption". -Dagordon01 19:08, 1 December 2007 (UTC)

Molasses

Macropores are being mentioned in this section and they are being defined as pores with a diameter larger than 2 nm. However, IUPAC has clearly defined porosity as : micropores (>2 nm), mesopores (2-50 nm), macropores (< 50 nm). So either the article is referring to mesopores (and bigger) or the diameter is not set right. Not quite sure what the author meant edit: after closer inspection on the subject, molasse number defines the surface area of pores > 2.8 nm. So should be mesopores.

This is now fixed but there's a similar problem in the methylene blue section: "Some carbons have a mesopore (20 Å to 50 Å, or 2 to 5 nm) structure which adsorbs medium size molecules, such as the dye methylene blue." IUPAC has 2 to 50 nm (20 Å to 500 Å) for mesopores. Typo, or is it describing those specific mesopores? If it's the latter, that should be made clear, anyway. Wombat140 (talk) 16:31, 13 March 2014 (UTC)

Properties

Some related questions: What is the distinction between non-porous and porous carbon? Also - what about porous graphitized carbon (PGC) (specifically - how is it made). PGC has applications as a stationary phase in some forms of liquid chromatography and solid phase extraction (e.g., Thermo's Hypercarb). And just what is graphitized carbon? —Preceding unsigned comment added by 159.14.241.230 (talk) 22:06, 15 January 2010 (UTC)

"Activated carbon does not bind well to... ammonia"??? Apparently that is a paradigm repeated throughout the web. However, there was an article entitled Adsorption Is the Word!, by Kenneth Sweezey (Popular Science, Oct 1946) that clearly instructed how a properly manufactured activated carbon specimen could completely adsorb ammonia gas that had evaporated from a sample of ammonium hydroxide. Hence, I am deleting the word ammonia from the string of substances that activated carbon cannot bind to.--Zymatik (talk) 02:40, 17 March 2010 (UTC)

Looks like someone stubbornly reverts these changes and plants these disinformations. Activated carbon eats ammonia like crazy. Here's a solid proof. Endimion17 (talk) 04:23, 2 November 2011 (UTC)

Bone Char

Activated carbon is used for filtering that things like Bone char can also be used for (esp. white sugar). At times (not on this article) the two are mixed up as the same and at other times as two different things. On the article here there is a list of things from which activated carbon may be made. Can we see some mention of Bone Char and wether activated carbon is a plant-only based substance? ~ R.T.G 21:01, 9 February 2010 (UTC)

Football Field Comparison

I don't want to enter a debate into which sport 'football' is - there's already a long enough one at http://en.wikipedia.org/wiki/Talk:Football - but the comparison "about one tenth the size of a football feld [sic]", whilst indeed correct for American Football (Field size approximately 5000m²), is inaccurate for Association Football/Soccer (Field size approximately 7000m²), Gaelic Football (approximately 10 000m²) and probably a number of 'football' sports. I feel this should really be changed to "about one tenth the size of an American Football field", or something else less misleading. Jamie.parkinson (talk) 18:40, 15 June 2010 (UTC)

OOPS TOO BULKY

This is really a lot to read come on it wouldn't hurt if it was shrunk a bit. —Preceding unsigned comment added by 122.56.193.64 (talk) 04:34, 26 June 2010 (UTC)

Improve the context - and help football lovers

To make the 500 sq meters per gram an even more understandable (and extraordinary) value it would be nice to compare this number with surface area/weight ratio values of different solids such as other finely ground powders. The football field comparison would also become more meaningful. (And talking about context: - to Jamie above - I enjoyed your comment regarding "which" football field; not a football fan myself I never would have thought of this. LSNED.)Evensteven2000 (talk) 13:22, 13 August 2010 (UTC)

> Each particle in this image, despite being only around 0.1 mm wide, has a surface area of several square metres. The entire image covers a region of approximately 1.1 by 0.7 mm

I would like to see a reference to this... I cannot believe that an area of 1.1 x 0.7 mm = 0.77 mm² activated coal has a surface area of several square metres, like a TARDIS. 145.53.180.22 (talk) 11:10, 4 February 2012 (UTC)

Effective for ozone absorption or as decomposition catalyst?

I am trying to find information on activated carbon and whether it can work as a catalyst for ozone decomposition in exhaust air from a high-voltage electrostatic precipitator.

Does activated carbon just simply absorb ozone like other pollutants, or does it actively break the ozone down into oxygen gas?

Also it is unclear if the carbon is capable of reactivation when it no longer effective at absorbing or catalyzing ozone. Some webpages seem to suggest that the carbon undergoes a molecular transformation after contact with ozone that effectively renders it useless and thermal reactivation can not restore the carbon, but they don't bother to describe the chemical reaction that would cause this loss of reactivatability.

DMahalko (talk) 19:59, 6 July 2011 (UTC)

Link to "Iodine number" misleading

The link Iodine number seems to be referring to quite another "iodine number", namely, the quantity of I₂ that can be added to an unsaturated compound (used for characterization of fats). --178.15.77.72 (talk) 13:49, 11 July 2011 (UTC)

Older methods of preparation

According to http://www.carbochem.com/activatedcarbon101.html ,activated carbon has been around for 2000 years. And other sites describe 18th century people eating poisons along with the activated carbon, to demonstrate its capabilities. Yet.... all the methodologies for preparation described here, are purely modern industrially-biased methods. It would be good to have a section on historical preparation methods. (I'd add it, if only I knew....) 173.206.176.222 (talk) 06:31, 13 July 2011 (UTC)

Too many sections header

I personally don't find this to be an issue with this article, but want community consensus before I remove it (if I can)Sklifnir (talk) 15:29, 18 December 2011 (UTC)

um

DMahalko's edit was tagged "citation needed", but I suppose that if anyone attempted to see if activated carbon could be reactivated in a toaster oven they'd find that charcoal catches fire. May I suggest someone who thinks Wikipedia shouldn't be dangerously flawed remove the questionable edit? - 173.24.245.10 (talk) 08:53, 14 March 2012 (UTC)

Completely agreed. It is common sense that activated carbon cannot be regenerated by a propane torch in air. I have removed it.Testem (talk) 11:53, 27 August 2013 (UTC)

condense tag

I removed the condense tag that has been on this article since 2009. The subject is expansive and having a lot of headers/sections allows for easier navigation.Righteousskills (talk) 20:03, 18 May 2012 (UTC)

In "Production", "burnt into ashes" is incorrect!

"Important production materials include coconut shells, palm shells, oil, husks, and sawdust, all of which have to be burnt into ashes for activated carbon making."

I will leave the fix to the experts should they wish to make it, but ... wrong, wrong, wrong! When something is "burnt into ashes" there is nothing left but inorganic, inoxidizable material. If you have burnt coconut shells, etc. to ashes, the carbon has all been oxidized to carbon dioxide (perhaps there is some CO gas as well). There is no carbon left ... no charcoal. You will be frustrated in your attempt to make activated carbon this way and will go broke.

Incorrect information!

Tom Cohoe (talk) 01:10, 13 January 2013 (UTC)

Adsorb / absorb

Adsorb and absorb mean different things, but seem to be used interchangeably in the article. Adsorption is the process whereby molecules of one substance become attached to the surface of another, rather than being absorbed into it.

I'm not a chemist, so I'm not in a position to check all the instances of the two words, but at present I have no confidence at all in the correctness of any of the occurrences of absorb. They all look to me as though they should be adsorb, since my understanding is that activated carbon works by attaching molecules onto the surface of its particles, and not by absorbing them into the particles.

Absorb occurs numerous times, but the quality of the surrounding writing makes it seem more likely to be carelessness than a deliberate distinction.

Please can a chemist check this? Musiconeologist (talk) 00:43, 26 January 2013 (UTC)

It looks like "absorb" is widely misused within this article. In other places it is sort of appropriate but for the sake of consistency and clarity, other terms like "filter" or "remove" should be used. I have hopefully now removed any inappropriate mentions of absorption. Testem (talk) 12:10, 27 August 2013 (UTC)

@Testem I think I missed this reply at the time, but thank you for doing that! Musiconeologist (talk) 23:25, 3 March 2024 (UTC)

Fair use candidate from Commons: File:Activated-carbon.jpg

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Excessive referencing in "Chemical properties and modification"

There cannot be the need for ten references on a single minor claim. Could someone have a look to see which are most relevant and remove all but a couple. https://en.wikipedia.org/wiki/Activated_carbon#Chemical_properties_and_modification Testem (talk) 12:18, 27 August 2013 (UTC)

Charcoal vs. biochar

"Activated carbon is usually derived from charcoal and increasingly, high-porosity biochar." This doesn't make much sense by the definition of "biochar" on the "Biochar" page, which says that "biochar" is just a term for charcoal used for agriculture. What is it supposed to mean? Wombat140 (talk) 15:20, 13 March 2014 (UTC)

Error in dechlorination section

You have the following statement and it may be in error. half of 5 is 2.5 not 3.5. -- clip -- The dechlorination half-value length is the depth of carbon required to reduce the chlorine level of a flowing stream from 5 ppm to 3.5 ppm. -- clip --

Robert Dell (talk) 00:17, 23 March 2015 (UTC)

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Mod to photomicrograph caption

The photomicrograph used to have a caption claiming that a 0.1mm diameter particle of activated carbon might have an area of several square meters, and linking to Cabot Corp. promotional literature.

From the article itself, 1 gram of activated charcoal has a surface area of up to ~3e3 square meters. The density of activated charcoal is about 0.2, so a 0.1mm cubic granule would have about 0.006 square meters of surface area (6 square centimeters). zowie (talk) 05:16, 5 December 2017 (UTC)

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Corn?

Currently the lede of the article claims that "[w]hen derived from coal or corn it is referred to as activated coal". This is the only reference to corn in the entire article, and as far as I can tell neither cited source makes any mention of corn. Without a source, this is nonsensical on its face: why, out of all the potential biological sources of carbon, is activated charcoal sourced from corn specifically called "activated coal"? Is there some nonbiological meaning of "corn" I don't know about, that would explain this? Neither our disambig page for corn nor Wiktionary list anything relevant. 「ディノ奴千？！」^{☎ Dinoguy1000} 14:43, 20 January 2020 (UTC)

Since it's been almost two weeks without any other comments here, I've removed "or corn" from the lede. 「ディノ奴千？！」^{☎ Dinoguy1000} 17:27, 31 January 2020 (UTC)

Photo of activated charcoal bread

Can we get rid of that photo? It's pseudoscientific and potentially dangerous. Dilbert08 21:55, 9 July 2021 (UTC)

Agreed! 2001:B011:1006:97AE:B065:138:E105:EB05 (talk) 05:31, 21 July 2022 (UTC)

Comparison of surface area vs. volume

I added a minor change: it's more correct to say that activated carbon has a "high surface-area-to-volume ratio" than having "more surface area than volume".

This is because values with different units should not be directly compared through subtraction. I.e. an activated carbon bead might have a numerically larger surface area than volume if you measure in m2 and m3. But if you change units to cm2 and cm3, the carbon bead could have a numerically larger volume than surface area. Using a ratio makes more sense. Even though the ratio of surface area vs. volume may change with the arbitrary choice of units, activated carbon's relatively "high" ratio (compared with that of other materials, such as pebbles) will remain relatively high. 35drake (talk) 17:56, 10 February 2023 (UTC)

Carbon

Tamil Ranjithkumarkutty (talk) 14:21, 26 February 2023 (UTC)

Not Ranjithkumarkutty (talk) 14:21, 26 February 2023 (UTC)