Activated carbon 1

Activated carbon

Activated carbon

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Activated carbon, also called activated charcoal or activated coal, is a form of carbon that has been processed tomake it extremely porous and thus to have a very large surface area available for adsorption or chemical reactions. [1]

The word activated in the name is sometimes substituted by active. Due to its high degree of microporosity, just onegram of activated carbon has a surface area in excess of 500 m² (or about 2 tennis courts), as determined typically bynitrogen gas adsorption. Sufficient activation for useful applications may come solely from the high surface area,though further chemical treatment often enhances the adsorbing properties of the material. Activated carbon isusually derived from charcoal.

ProductionActivated carbon is produced from carbonaceous source materials like nutshells, wood and coal. It can be producedby one of the following processes:1. Physical reactivation: The precursor is developed into activated carbons using gases. This is generally done by

using one or a combination of the following processes:• Carbonization: Material with carbon content is pyrolyzed at temperatures in the range 600-900 °C, in absence

of air (usually in inert atmosphere with gases like argon or nitrogen)• Activation/Oxidation: Raw material or carbonised material is exposed to oxidizing atmospheres (carbon

dioxide, oxygen, or steam) at temperatures above 250 °C, usually in the temperature range of 600-1200 °C.2. Chemical activation: Prior to carbonization, the raw material is impregnated with certain chemicals. The

chemical is typically an acid, strong base, or a salt (phosphoric acid, potassium hydroxide, sodium hydroxide, zinc chloride, respectively). Then, the raw material is carbonized at lower temperatures (450-900 °C). It is believed that the carbonization / activation step proceeds simultaneously with the chemical activation. This technique can be problematic in some cases, because, for example, zinc trace residues may remain in the end

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product. However, chemical activation is preferred over physical activation owing to the lower temperatures andshorter time needed for activating material.

PropertiesA gram of activated carbon can have a surface area in excess of 500 m², with 1500 m² being readily achievable[2] .Carbon aerogels, while more expensive, have even higher surface areas, and are used in special applications.Under an electron microscope, the high surface-area structures of activated carbon are revealed. Individual particlesare intensely convoluted and display various kinds of porosity; there may be many areas where flat surfaces ofgraphite-like material run parallel to each other, separated by only a few nanometers or so. These micropores providesuperb conditions for adsorption to occur, since adsorbing material can interact with many surfaces simultaneously.Tests of adsorption behaviour are usually done with nitrogen gas at 77 K under high vacuum, but in everyday termsactivated carbon is perfectly capable of producing the equivalent, by adsorption from its environment, liquid waterfrom steam at 100 °C and a pressure of 1/10,000 of an atmosphere.Physically, activated carbon binds materials by Van der Waals force or London dispersion force.Activated carbon does not bind well to certain chemicals, including alcohols, glycols, ammonia, strong acids andbases, metals and most inorganics, such as lithium, sodium, iron, lead, arsenic, fluorine, and boric acid. Activatedcarbon does adsorb iodine very well and in fact the iodine number, mg/g, (ASTM D28 Standard Method test) is usedas an indication of total surface area.Activated carbon can be used as a substrate for the application of various chemicals to improve the adsorptivecapacity for some inorganic (and problematic organic) compounds such as hydrogen sulfide (H2S), ammonia (NH3),formaldehyde (HCOH), radioisotopes iodine-131 (131I) and mercury (Hg). This property is known as chemisorption.

ClassificationsActivated carbons are complex products which are difficult to classify on the basis of their behaviour, surfacecharacteristics and preparation methods. However, some broad classification is made for general purpose based ontheir physical characteristics.

Powdered activated carbon (PAC)Traditionally, active carbons are made in particular form as powders or fine granules less than 1.0 mm in size withan average diameter between .15 and .25 mm.[3] Thus they present a large surface to volume ratio with a smalldiffusion distance. PAC is made up of crushed or ground carbon particles, 95–100% of which will pass through adesignated mesh sieve or sieve. Granular activated carbon is defined as the activated carbon being retained on a50-mesh sieve (0.297 mm) and PAC material as finer material, while ASTM classifies particle sizes correspondingto an 80-mesh sieve (0.177 mm) and smaller as PAC. PAC is not commonly used in a dedicated vessel, owing to thehigh headloss that would occur. PAC is generally added directly to other process units, such as raw water intakes,rapid mix basins, clarifiers, and gravity filters.

Granular activated carbon (GAC)Granular activated carbon has a relatively larger particle size compared to powdered activated carbon and consequently, presents a smaller external surface. Diffusion of the adsorbate is thus an important factor. These carbons are therefore preferred for all adsorption of gases and vapours as their rate of diffusion are faster. Granulated carbons are used for water treatment, deodourisation and separation of components of flow system. GAC can be either in the granular form or extruded. GAC is designated by sizes such as 8x20, 20x40, or 8x30 for liquid phase applications and 4x6, 4x8 or 4x10 for vapour phase applications. A 20x40 carbon is made of particles that will pass through a U.S. Standard Mesh Size No. 20 sieve (0.84 mm) (generally specified as 85% passing) but be retained on a

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U.S. Standard Mesh Size No. 40 sieve (0.42 mm) (generally specified as 95% retained). AWWA (1992) B604 usesthe 50-mesh sieve (0.297 mm) as the minimum GAC size. The most popular aqueous phase carbons are the 12x40and 8x30 sizes because they have a good balance of size, surface area, and headloss characteristics.

Extruded activated carbon (EAC)Consists of extruded and cylindrical shaped activated carbon with diameters from 0.8 to 45 mm. These are mainlyused for gas phase applications because of their low pressure drop, high mechanical strength and low dust content.

Impregnated carbonPorous carbons containing several types of inorganic impregnant such as iodine, silver, cation such as Al, Mn, Zn,Fe, Li, Ca have also been prepared for specific application in air pollution control especially in museums andgalleries. Due to antimicrobial/antiseptic properties, silver loaded activated carbon is used as an adsorbent forpurifications of domestic water. Drinking water can be obtained from natural water by treating the natural water witha mixture of activated carbon and flocculating agent Al(OH)3. Impregnated carbons are also used for the adsorptionof H2S and mercaptans. Adsorption rates for H2S as high as 50% by weight have been reported.

Polymers coated carbonThis is a process by which a porous carbon can be coated with a biocompatible polymer to give a smooth andpermeable coat without blocking the pores. The resulting carbon is useful for hemoperfusion. Hemoperfusion is atreatment technique in which large volumes of the patient's blood are passed over an adsorbent substance in order toremove toxic substances from the blood.

OtherActivated carbon is also available in special forms such as cloths and fibres. The "Carbon cloth" for instance is usedin personnel protection for the military.

Properties of activated carbon

Iodine NumberMany carbons preferentially adsorb small molecules. Iodine number is the most fundamental parameter used tocharacterize activated carbon performance. It is a measure of activity level (higher number indicates higher degree ofactivation), often reported in mg/g (typical range 500-1200 mg/g). It is a measure of the micropore content of theactivated carbon (0 to 20 Å, or up to 2 nm) by adsorption of iodine from solution. It is equivalent to surface area ofcarbon between 900 m²/g and 1100 m²/g. It is the standard measure for liquid phase applications.Iodine number is defined as the milligrams of iodine adsorbed by one gram of carbon when the iodine concentrationin the residual filtrate is 0.02 normal. Basically, iodine number is a measure of the iodine adsorbed in the pores and,as such, is an indication of the pore volume available in the activated carbon of interest. Typically, water treatmentcarbons have iodine numbers ranging from 600 to 1100. Frequently, this parameter is used to determine the degreeof exhaustion of a carbon in use. However, this practice should be viewed with caution as chemical interactions withthe adsorbate may affect the iodine uptake giving false results. Thus, the use of iodine number as a measure of thedegree of exhaustion of a carbon bed can only be recommended if it has been shown to be free of chemicalinteractions with adsorbates and if an experimental correlation between iodine number and the degree of exhaustionhas been determined for the particular application.

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MolassesSome carbons are more adept at adsorbing large molecules. Molasses number or molasses efficiency is a measure ofthe mesopore content of the activated carbon (greater than 20 Å, or larger than 2 nm) by adsorption of molasses fromsolution. A high molasses number indicates a high adsorption of big molecules (range 95-600). Caramel dp(decolorizing performance) is similar to molasses number. Molasses efficiency is reported as a percentage (range40%-185%) and parallels molasses number (600 = 185%, 425 = 85%). The European molasses number (range525-110) is inversely related to the North American molasses number.Molasses Number is a measure of the degree of decolorization of a standard molasses solution that has been dilitedand standardized against standardized activated carbon. Due to the size of color bodies, the molasses numberrepresents the potential pore volume available for larger adsorbing species. As all of the pore volume may not beavailable for adsorption in a particular waste water application, and as some of the adsorbate may enter smallerpores, it is not a good measure of the worth of a particular activated carbon for a specific application. Frequently, thisparameter is useful in evaluating a series of active carbons for their rates of adsorption. Given two active carbonswith similar pore volumes for adsorption, the one having the higher molasses number will usually have larger feederpores resulting in more efficient transfer of adsorbate into the adsorption space.

TanninTannins are a mixture of large and medium size molecules. Carbons with a combination of macropores andmesopores adsorb tannins. The ability of a carbon to adsorb tannins is reported in parts per million concentration(range 200 ppm-362 ppm).

Methylene blueSome carbons have a mesopore (20 Å to 50 Å, or 2 to 5 nm) structure which adsorbs medium size molecules, such asthe dye methylene blue. Methylene blue adsorption is reported in g/100g (range 11-28 g/100g).

DechlorinationSome carbons are evaluated based on the dechlorination half-value length, which measures the chlorine-removalefficiency of activated carbon. The dechlorination half-value length is the depth of carbon required to reduce thechlorine level of a flowing stream from 5 ppm to 3.5 ppm. A lower half-value length indicates superior performance.

Apparent densityHigher density provides greater volume activity and normally indicates better quality activated carbon.

Hardness/abrasion numberIt is a measure of the activated carbon’s resistance to attrition. It is important indicator of activated carbon tomaintain its physical integrity and withstand frictional forces imposed by backwashing, etc. There are largedifferences in the hardness of activated carbons, depending on the raw material and activity level.

Ash contentIt reduces the overall activity of activated carbon. It reduces the efficiency of reactivation. The metals (Fe2O3) canleach out of activated carbon resulting in discoloration. Acid/water soluble ash content is more significant than totalash content. Soluble ash content can be very important for aquarists, as ferric oxide can promote algal growths, acarbon with a low soluble ash content should be used for marine, freshwater fish and reef tanks to avoid heavy metalpoisoning and excess plant/algal growth.

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Carbon tetrachloride activityMeasurement of the porosity of an activated carbon by the adsorption of saturated carbon tetrachloride vapour.

Particle size distributionThe finer the particle size of an activated carbon, the better the access to the surface area and the faster the rate ofadsorption kinetics. In vapour phase systems this needs to be considered against pressure drop, which will affectenergy cost. Careful consideration of particle size distribution can provide significant operating benefits.

Examples of adsorption

Heterogeneous catalysisThe most commonly encountered form of chemisorption in industry, occurs when a solid catalyst interacts with agaseous feedstock, the reactant/s. The adsorption of reactant/s to the catalyst surface creates a chemical bond,altering the electron density around the reactant molecule and allowing it to undergo reactions that would notnormally be available to it.

Adsorption refrigerationAdsorption refrigeration and heat pump cycles rely on the adsorption of a refrigerant gas into an adsorbent at lowpressure and subsequent desorption by heating. The adsorbent acts as a "chemical compressor" driven by heat and is,from this point of view, the "pump" of the system. It consists of a solar collector, a condenser or heat-exchanger andan evaporator that is placed in a refrigerator box. The inside of the collector is lined with an adsorption bed packedwith activated carbon adsorbed with methanol. The refrigerator box is insulated filled with water. The activatedcarbon can adsorb a large amount of methanol vapours in ambient temperature and desorb it at a higher temperature(around 100 degrees Celsius). During the daytime, the sunshine irradiates the collector, so the collector is heated upand the methanol is desorbed from the activated carbon. In desorption, the liquid methanol adsorbed in the charcoalheats up and vaporizes. The methanol vapour condenses and is stored in the evaporator.At night, the collector temperature decreases to the ambient temperature, and the charcoal adsorbs the methanol fromthe evaporator. The liquid methanol in the evaporator vaporizes and absorbs the heat from the water contained in thetrays. Since adsorption is a process of releasing heat, the collector must be cooled efficiently at night. As mentionedabove, the adsorption refrigeration system operates in an intermittent way to produce the refrigerating effect.Helium gas can also be 'pumped' by thermally cycling activated carbon 'sorption pumps' between 4 kelvins andhigher temperatures. An example of this is to provide the cooling power for the Oxford Instruments AST seriesdilution refrigerators. 3He vapour is pumped from the surface of the dilute phase of a mixture of liquid 4He and itsisotope 3He. The 3He is adsorbed onto the surfaces of the carbon at low temperature (typically <4K), theregeneration of the pump between 20 and 40 K returns the 3He to the concentrated phase of the liquid mixture.Cooling occurs at the interface between the two liquid phases as 3He 'evaporates' across the phase boundary. If morethan one pump is present in the system a continuous flow of gas and hence constant cooling power can be obtained,by having one sorption pump regenerating while the other is pumping. Systems such as this allow temperatures aslow as 10 mK (0.01 kelvin) to be obtained with very few moving parts.

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ApplicationsActivated carbon is used in gas purification, gold purification, metal extraction, water purification, medicine, sewagetreatment, air filters in gas masks and filter masks, filters in compressed air and many other applications.One major industrial application involves use of activated carbon in metal finishing field. It is very widely employedfor purification of electroplating solutions. For example, it is a main purification technique for removing organicimpurities from bright nickel plating solutions. A variety of organic chemicals are added to plating solutions forimproving their deposit qualities and for enhancing properties like brightness, smoothness, ductility, etc. Due topassage of direct current and electrolytic reactions of anodic oxidation and cathodic reduction, organic additivesgenerate unwanted break down products in solution. Their excessive build up can adversely affect the plating qualityand physical properties of deposited metal. Activated carbon treatment removes such impurities and restores platingperformance to the desired level.

Environmental applicationsCarbon adsorption has numerous applications in removing pollutants from air or water streams both in the field andin industrial processes such as:• Spill cleanup• Groundwater remediation• Drinking water filtration• Air purification• Volatile organic compounds capture from painting, dry cleaning, gasoline dispensing operations, and other

processes.In 2007, West-Flanders University (in Belgium) began research in water treatment after festivals . A full scaleactivated carbon installation, was built at the Dranouter music festival in 2008 , with plans to utilize the technologyto treat water at this festival for the next 20 years .Activated charcoal is also used for the measurement of radon concentration in air.

Medical applicationsActivated carbon is used to treat poisonings and overdoses following oral ingestion.It is thought to bind to poison and prevent its absorption by the gastrointestinal tract. In cases of suspected poisoning,medical personnel administer activated charcoal on the scene or at a hospital's emergency department. Dosing isusually empirical at 1 gram/kg of body weight ( for adolescents or adults, give 50–100 g ), usually given only once,but depending on the drug taken, it may be given more than once. In rare situations activated charcoal is used inIntensive Care to filter out harmful drugs from the blood stream of poisoned patients. Activated carbon has becomethe treatment of choice for many poisonings, and other decontamination methods such as ipecac-induced emesis orstomach pumping are now used rarely.While activated carbon is useful in an acute poisoning situation, it has been shown to not be effective in long termaccumulation of toxins, such as with the use of toxic herbicides.[4]

Mechanisms of action:• Binding of the toxin to prevent stomach and intestinal absorption. Binding is reversible so a cathartic such as

sorbitol may be added as well.• It interrupts the enterohepatic circulation of some drugs/toxins and their metabolitesIncorrect application (e.g. into the lungs) results in pulmonary aspiration which can sometimes be fatal if immediatemedical treatment is not initiated.[5] The use of activated charcoal is contraindicated when the ingested substance isan acid, an alkali, or a petroleum product.

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For pre-hospital use, it comes in plastic tubes or bottles, commonly 12.5 or 25 grams, pre-mixed with water. Thetrade names include InstaChar, SuperChar, Actidose, and Liqui-Char, but it is commonly called Activated Charcoal.Ingestion of activated carbon prior to consumption of ethanol has been shown to reduce absorption of alcohol intothe blood. 5 to 15 milligrams of charcoal per kilogram of body weight taken at the same time as 170 ml of pureethanol (which equals about 10 servings of an alcoholic beverage alcohol, or 17 shots), over the course of one hour,has very apparent effects at reducing potential blood alcohol content[6]

In the past charcoal biscuit was sold in England in the early 19th century, originally as an antidote to flatulence andstomach trouble.[7]

Tablets of activated charcoal are still used as a folk remedy and over-the-counter drug to treat diarrhea, indigestion,and flatulence.[8] They were also used in the past by doctors for this purpose. There is some evidence of itseffectiveness as a treatment for irritable bowel syndrome (IBS),[9] and to prevent diarrhea in cancer patients whohave received irinotecan.[10] It can interfere with the absorbency of some medications, and lead to unreliablereadings in medical tests such as the guaiac card test.[11] A type of charcoal biscuit has been marketed as a pet careproduct.Activated charcoal is also used for bowel preparation by reducing intestinal gas content before abdominalradiography to visualize bile, pancreatic and renal stones.

Fuel StorageResearch is being done testing various activated carbons ability to store natural gas and hydrogen gas. The porousmaterial acts like a sponge for different types of gasses. The gas is attracted to the carbon material via Van der Waalsforces. Some carbons have been able to achieve bonding energies of 5-10 KJ per mol. The gas may then be desorbedwhen subjected to higher temperatures and either combusted to do work or in the case of hydrogen gas extracted foruse in a hydrogen fuel cell. Gas storage in activated carbons is an appealing gas storage method because the gas canbe stored in a low pressure, low mass, low volume environment that could would be much more feasible than bulkyon board compression tanks in vehicles. The United States Department of Energy has specified certain goals to beachieved in the area of research and development of nano-porous carbon materials. As of yet all of the goals are yetto be satisfied but numerous institutions, including the ALL-CRAFT program, are continuing to conduct work in thispromising field.

Gas purificationFilters with activated carbon are usually used in compressed air and gas purification to remove oil vapours, odours,and other hydrocarbons from the air. The most common designs use a 1 stage or 2 stage filtration principle in whichactivated carbon is embedded inside the filter media. Activated charcoal is also used in spacesuit Primary LifeSupport Systems. Activated charcoal filters are used to retain radioactive gases from a nuclear boiling water reactorturbine condenser. The air vacuumed from the condenser contains traces of radioactive gases. The large charcoalbeds adsorb these gases and retains them while they rapidly decay to non-radioactive solid species. The solids aretrapped in the charcoal particles, while the filtered air passes through.

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Chemical PurificationCommonly used to purify homemade non-dangerous chemicals such as sodium acetate. It is then filtered out.

Distilled alcoholic beverage purificationActivated carbon filters can be used to filter vodka and whiskey of organic impurities which can affect color, taste,and odor. Passing an organically impure vodka through an activated carbon filter at the proper flow rate will result invodka with an identical alcohol content and significantly increased organic purity, as judged by odor and taste.

Mercury scrubbingActivated carbon, often impregnated with iodine or sulfur, is widely used to trap mercury emissions from coal firedpower stations, medical incinerators, and from natural gas at the wellhead. This carbon is a specialty product costingmore than $4.00 per kg. However, it is often not recycled.

Disposal in the USAThe mercury laden activated carbon presents a disposal dilemma. If the activated carbon contains less than 260 ppmmercury, Federal regulations allow it to be stabilized (for example, trapped in concrete) for landfilling. However,waste containing greater than 260 ppm is considered to be in the high mercury subcategory and is banned fromlandfilling (Land-Ban Rule). It is this material which is now accumulating in warehouses and in deep abandonedmines at an estimated rate of 1000 tons per year.The problem of disposal of mercury laden activated carbon is not unique to the U.S. In the Netherlands this mercuryis largely recovered[12] and the activated carbon is disposed by complete burning.

See also• Carbon black• Carbon filtering• Kværner-process• Onboard refueling vapor recovery• Sumi• Zeocarbon

External links• "Activated Carbon for water filtration" [13] - Treatment Systems for Household Water Supplies] AE-1029,

February 1992• "Imaging the atomic structure of activated carbon" [14] - JOURNAL OF PHYSICS: CONDENSED MATTER• Engber, Daniel (Nov. 28, 2005). "How Does Activated Carbon Work?" [15]. Slate.

References[1] "Properties of Activated Carbon", CPL Caron Link, accessed 2008-05-02 (http:/ / www. activated-carbon. com/ 1-3. html)[2] Value Added Products from Gasification (http:/ / cgpl. iisc. ernet. in/ site/ Portals/ 0/ Publications/ Presentations/ Bio-Energy/ Value Added

Products From Gasification - Activated Carbon. pdf) - Acitivated Carbon, By Shoba jhadhav, The Combustion,Gasification and PropulsionLaboratory (CGPL) at the Indian Institute of Science (IISc)

[3] http:/ / en. mimi. hu/ astronomy/ granule. html[4] Eddleston M, Juszczak E, Buckley NA, et al. (2008). "Multiple-dose activated charcoal in acute self-poisoning: a randomised controlled

trial". Lancet 371 (9612): 579. doi: 10.1016/S0140-6736(08)60270-6 (http:/ / dx. doi. org/ 10. 1016/ S0140-6736(08)60270-6).[5] Elliott C, Colby T, Kelly T, Hicks H (1989). "Charcoal lung. Bronchiolitis obliterans after aspiration of activated charcoal". Chest 96 (3):

672–4. doi: 10.1378/chest.96.3.672 (http:/ / dx. doi. org/ 10. 1378/ chest. 96. 3. 672). PMID 2766830.

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[6] Procter, Richard & Stanton Anondson, "Method of altering intoxicating effects of alcohol", US 4594249 (http:/ / v3. espacenet. com/textdoc?DB=EPODOC& IDX=US4594249), issued 1986

[7] Rolland, Jacques L. (2006). The Food Encyclopedia: Over 8,000 Ingredients, Tools, Techniques and People. Robert Rose. pp. 148. ISBN0778801500.

[8] Stearn, Margaret (2007). Warts and all: straight talking advice on life's embarrassing problems (http:/ / books. google. co. uk/books?id=aSRmxC47VNMC& printsec=frontcover#PPA333). London: Murdoch Books. p. 333. ISBN 978-1-92125984-5. . Retrieved2009-05-03.

[9] Hübner WD, Moser EH (2002). " Charcoal tablets in the treatment of patients with irritable bowel syndrome (https:/ / www.advancesintherapy. com/ detail. aspx?ID=276)". Adv Ther 19 (5): 245–52. doi: 10.1007/BF02850364 (http:/ / dx. doi. org/ 10. 1007/BF02850364). PMID 12539884. .

[10] Michael M, Brittain M, Nagai J, et al. (Nov 2004). "Phase II study of activated charcoal to prevent irinotecan-induced diarrhea". J ClinOncol. 22 (21): 4410–7. doi: 10.1200/JCO.2004.11.125 (http:/ / dx. doi. org/ 10. 1200/ JCO. 2004. 11. 125). PMID 15514383.

[11] Gogel HK, Tandberg D, Strickland RG (Sep 1989). "Substances that interfere with guaiac card tests: implications for gastric aspiratetesting". Am J Emerg Med 7 (5): 474–80. doi: 10.1016/0735-6757(89)90248-9 (http:/ / dx. doi. org/ 10. 1016/ 0735-6757(89)90248-9). PMID2787993.

[12] BMT-Begemann, Mercury waste treatment facilities (http:/ / www. bmt-begemann. nl/ index. html)[13] http:/ / www. ag. ndsu. edu/ pubs/ h2oqual/ watsys/ ae1029w. htm[14] http:/ / www. personal. rdg. ac. uk/ ~scsharip/ Activated_carbon_JPCM. pdf[15] http:/ / www. slate. com/ id/ 2131130/

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Article Sources and ContributorsActivated carbon  Source: http://en.wikipedia.org/w/index.php?oldid=315672151  Contributors: AlexandriNo, Ali@gwc.org.uk, Alison, Allstrak, Angela, Arcadian, Arcadie, Bigballer09,Bigmak, Borgx, C6541, CGameProgrammer, Caiaffa, Capuchin, Dagordon01, DanielCD, Davidhorman, DerekLaw, Dforest, Discospinster, Dragonix, Ds13, ESkog, Elbreapoly, Element16,Elkman, Entlinkt, Erik Klapton, Foobar, Fratrep, Fredgamble, Freestyle-69, FreplySpang, Friederich, Gadfium, Gak, Gene Nygaard, Ghosts&empties, Giftlite, Gilliam, Gioto, GreatMizuti,Habibfriend, Haoie, Heron, Hooperbloob, Hu12, Huy Q Pham, IScorpio, IceCreamAntisocial, Icek, Imnotminkus, J.delanoy, JamesChemFindIt, Jcarroll, JeffAMcGee, Jgrundli, JidGom,Jimjamjak, Joelmills, Johnleemk, Jscb, K4carbon, KFP, Keenan Pepper, Kelisi, Kenyon, Kjkolb, Klosterdev, Layeredsurface, Leyo, LiDaobing, LilHelpa, Luis v silva, Lysdexia, Mark.murphy,Masiano, MatthewBelleghem, Mbell, Merkurix, Metju, Mion, Miranda, MisterSheik, Mmoneypenny, Mr Bungle, Murtasa, NawlinWiki, Ncmvocalist, Neale Monks, Neffk, Neonumbers, Nergaal,Nofreak, NormanEinstein, Onceler, Oreo Priest, Pengo, PlantTrees, Polychrome, Preslethe, Qrater, RDBrown, Rabid, Rabogliatti, Ravedave, Raven in Orbit, Rich Farmbrough, Rjwilmsi, RyanRoos, Ryanyahoo, Salsa Shark, Sanders muc, Shaddack, Sharifneuro, Sharkface217, Shcha, Sjschen, Snurks, Spartan-James, Spiritia, Stephenb, Sticky Parkin, Suhasnatyan, Swpb, Szalzala, TheVindictive, Tigerhawkvok, Uthbrian, Verdatum, Wavelength, WaysToEscape, Wbgr, Willbedoctor, Willking1979, Wim.audenaert, WriterHound, Xhienne, Zaytran, Zetawoof, 293 anonymousedits

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