Talk:Activated carbon

message: 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)
thread_title: Arsenic

message: 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)
thread_title: Need image from electron microscope

message: "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)
thread_title:  Incomprehensible 

message: 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  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)
replies: text: 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)
replies: text: I also removed the section allegedly relating to "traditional medicine".Jimjamjak (talk) 13:43, 24 July 2008 (UTC)
thread_title:  Clean up? 

message: "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)
thread_title:  Alcohols 

message: 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)
thread_title:  Desorption and recovery 

message: 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)
thread_title:  Vodka 

message: 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)
replies: text: 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)
replies: text: 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)
thread_title:  Carborabbi 

message: 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)
thread_title:  Examples of adsorption SECTION 

message: 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)
thread_title:  Molasses 

message: 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)
thread_title:  Properties 

message: 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)
thread_title:  Bone Char 

message: 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)
thread_title:  Football Field Comparison 

message: 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)
thread_title: OOPS TOO BULKY

message: 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)
thread_title:  Effective for ozone absorption or as decomposition catalyst? 

message: 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)
thread_title:  Link to "Iodine number" misleading 

message: 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)
thread_title:  Older methods of preparation 

message: 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)
thread_title:  Too many sections header 

message: 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)
replies: text: 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)
thread_title:  um 

message: 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)
thread_title: condense tag

message: "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)
thread_title:  In "Production", "burnt into ashes" is incorrect! 

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

message: The file :File:Activated-carbon.jpg, used on this page, has been deleted from Wikimedia Commons and re-uploaded at :File:Activated-carbon.jpg. It should be reviewed to determine if it is compliant with this project's non-free content policy, or else should be deleted and removed from this page. If no action is taken, it will be deleted after 7 days.  Commons fair use upload bot (talk) 23:25, 14 June 2013 (UTC)
thread_title:  Fair use candidate from Commons: [[:File:Activated-carbon.jpg]] 

message: 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)
thread_title:  Excessive referencing in "Chemical properties and modification" 

message: "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)
thread_title:  Charcoal vs. biochar 

message: 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)
thread_title:  Error in dechlorination section 

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thread_title:  External links modified 

message: 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)
thread_title:  Mod to photomicrograph caption 

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thread_title:  External links modified (January 2018) 

message: 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)
replies: text: 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)
thread_title:  Corn? 

message: Can we get rid of that photo? It's pseudoscientific and potentially dangerous. Dilbert08 21:55, 9 July 2021 (UTC)
replies: text: Agreed! 2001:B011:1006:97AE:B065:138:E105:EB05 (talk) 05:31, 21 July 2022 (UTC)
thread_title:  Photo of activated charcoal bread 

message: 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)
thread_title:  Comparison of surface area vs. volume 

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