ACTIVATED CARBON

Activated Carbon is used for color lightening, removal of color-causing substances and purification purposes in sugar syrups obtained from sucrose obtained from sugar cane or beet, in other words, sugar and other starch derivatives such as glucose and maltose.
Activated Carbon is used removal of taste and odor causing compounds such as MIB and geosmin.
Activated Carbon is used recovery of gold.

CAS Number: 7440-44-0
EC (EINECS) Number: 231-153-3
Molecular Formula: C
Molecular Weight (Atomic Weight): 12.01 g/mol

SYNONYMS:
Activated carbon, activated charcoal, carbon molecular sieves, BONE BLACK, coconut shell activated carbon, plant nutshell activated carbon, medical activated carbon, BONE CHARCOAL, CHARCOAL BONE, huoxingt

Activated carbon, sometimes called activated charcoal, is a unique adsorbent prized for its extremely porous structure that allows it to effectively capture and hold materials.
Activated carbon, also known as activated charcoal, is a highly processed form of carbon that has been treated to develop a very large internal pore structure with an extremely high surface area.

Unlike ordinary charcoal, activated carbon undergoes a specific activation process — either physical or chemical — that opens up microscopic pores, transforming a carbonaceous material into a powerful adsorbent.
The result is a material with a surface area measured in the thousands of square meters per gram, making Activated Carbon exceptionally effective at capturing and holding molecules on its surface through adsorption.

While activated carbon can be manufactured in different ways and from diverse raw materials (such as coconut shells, wood, coal, peat, or nutshells), its distinguishing feature is its porous microcrystalline structure that allows molecules from gases or liquids to adhere to its vast internal surface.

This is why Activated Carbon is widely used in purification, filtration, and chemical processing applications across many industries.
Activated carbon, also called activated charcoal, is a form of carbon commonly used to filter contaminants from water and air, among many other uses.

Activated Carbon is processed (activated) to have small, low-volume pores that greatly increase the surface area available for adsorption or chemical reactions.
Adsorption, not to be confused with absorption, is a process where atoms or molecules adhere to a surface.

The pores can be thought of as a microscopic "sponge" structure.
Activation is analogous to making popcorn from dried corn kernels: popcorn is light, fluffy, and its kernels have a high surface-area-to-volume ratio.

Activated is sometimes replaced by active.
Because it is so porous on a microscopic scale, one gram of activated carbon has a surface area of over 3,000 square metres per gram (920,000 square feet per ounce), as determined by gas absorption and its porosity can run 10ML/day in terms of treated water per gram.

Researchers at Cornell University synthesized an ultrahigh surface area activated carbon with a BET area of 4,800 m2/g (1,500,000 sq ft/oz).
This BET area value is the highest reported in the literature for activated carbon to date.
For charcoal, the equivalent figure before activation is about 2–5 square metres per gram (610–1,530 sq ft/oz).
A useful activation level may be obtained solely from high surface area.

Further chemical treatment often enhances adsorption properties.
Activated carbon is usually derived from waste products such as coconut husks in addition to other agricultural wastes like olive stones, rice husks and nutshell shells which are also being upcycled into activated carbon, diversifying feedstock supply.

Furthermore, waste from paper mills has been studied as a possible source of activated carbon.
These bulk sources are converted into charcoal before being activated.
Using waste streams not only reduces landfill burden but also works to lower the overall carbon footprint of activated carbon production as previously discarded waste is now repurposed.

When derived from coal, it is referred to as activated coal.
Activated coke is derived from coke.
In activated-coke production, the raw coke (most commonly petroleum coke) is ground or pelletized, then "activated" via physical (steam or CO2 at high temperature) or chemical (e.g., KOH or H3PO4) methods to introduce a porous network, yielding a high-surface-area adsorbent which is referred to as activated coal.

Activated carbon, sometimes known as activated charcoal, has been commercially used as a purification media since the early 19th century.
Today, activated carbon comes in various forms and is used in many drinking water, industrial air and water treatment, businesses, and homes to remove contaminants.

Activated Carbon is a highly porous material that removes organic compounds from liquids and gases by a process known as “adsorption.”
Adsorption is where organic molecules in a liquid or gas, are attracted and adhere to the surface of the activated carbon, as the liquid or gas passes through it.

Adsorption on porous carbons was described as early as 1550 B.C. in an ancient Egyptian papyrus and later by Hippocrates and Pliny the Elder, mainly for medicinal purposes.
In fact, Archaeologists discovered that the earliest use of charcoal for water treatment dates back to around 400 B.C primarily among seafaring communities.

Sailors would char the insides of water barrels to purify and preserve the water during long ocean voyages.
In the 18th century, carbons made from blood, wood and animals were used for the purification of liquids.

All of these materials, which can be considered as precursors of activated carbons were only available then as a powder.
Activated carbon is a carbon-based material that has been processed to maximize its adsorptive properties, yielding a superior adsorbent material.

Activated carbon boasts an impressive pore structure that causes it to have a very high surface area on which to capture and hold materials, and can be produced from a number of carbon-rich organic materials, including:
*Coconut shells
*Wood
*Coal
*Peat
And more…

Depending on the source material, and the processing methods used to produce activated carbon, the physical and chemical properties of the end product can differ significantly.
This creates a matrix of possibilities for variation in commercially produced carbons, with hundreds of varieties available.
Because of this, commercially produced activated carbons are highly specialized to achieve the best results for a given application.

Despite such variation, there are three main types of activated carbon produced:
*Powdered Activated Carbon (PAC)
Powdered activated carbons generally fall in the particle size range of 5 to 150 Å, with some outlying sizes available.
PAC’s are typically used in liquid-phase adsorption applications and offer reduced processing costs and flexibility in operation.

*Granular Activated Carbon (GAC)
Granular activated carbons generally range in particle sizes of 0.2 mm to 5 mm and can be used in both gas and liquid phase applications.
GACs are popular because they offer clean handling and tend to last longer than PACs.
Additionally, they offer improved strength (hardness) and can be regenerated and reused.

*Extruded Activated Carbon (EAC)
Extruded activated carbons are a cylindrical pellet product ranging in size from 1 mm to 5 mm.
Typically used in gas phase reactions, EACs are a heavy-duty activated carbon as a result of the extrusion process.

*Additional Types
Additional varieties of activated carbon include:
*Bead Activated Carbon
*Impregnated Carbon
*Polymer Coated Carbon
*Activated Carbon Cloths
*Activated Carbon Fibers

*Activated carbon
The molecular media is at the heart of all successful molecular filtration solutions.
Activated carbon is an extremely versatile and powerful adsorbent.
Activated Carbon can be used to control the vast majority of all the different molecules that pollute the air, and there are more than one hundred and thirty million catalogued chemicals!

The most important characteristic of some activated carbons is "Broad Spectrum" adsorptive capacity.
These carbons are able to adsorb a huge range of different molecules.
This is a very important feature when the mix of chemicals is unknown, or variable, or perhaps too complex and expensive to analyse.

Activated carbon can be made from different raw materials, in different qualities and different shapes and sizes.
Adjusting these factors allow Camfil to optimize efficiency, lifetime and pressure loss for different customer applications.

Activated carbon operates with a physical adsorption or catalytic mechanism.
In some cases, both of the mechanisms might be important.
Activated carbon is a porous solid able to coordinate to itself various types of molecules.

This interaction can be of merely physical nature (attraction between non-bonded atoms or Van der Waals forces) or physical- chemical origin and its strength can vary depending upon the type of molecule and the type of activated carbon.
Activated carbon is usually produced by steam activation process, during which carbon or starting materials containing carbon atoms are partially gasified by reacting with steam or other oxidizing gases.

Raw materials such as charcoal, bituminous coal, lignite, coconut charcoal, peat coke or hard wood are used.
In addition, chemical activation can also be used to activate raw materials containing cellulose.
Sawdust for example, is treated with chemicals that have a dehydrating effect at high temperature.

Both processes result in porous carbon which consists in an extremely porous structure with highly developed internal surface that can range from 500 up to 1500 square meters per gram of carbon.
Activated carbon or activated charcoal is a porous element that traps compounds, primarily organic, present in a gas or liquid.

Activated Carbon does this so effectively that it is the most widely used purifying agent by humans.
On the other hand, organic compounds are derived from the metabolism of living beings, and their basic structure consists of chains of carbon and hydrogen atoms.

These include all derivatives from the plant and animal world, including petroleum and the compounds obtained from it.
The property of a solid to adhere a flowing molecule to its walls is called “adsorption”.
The solid is called “adsorbent” and the molecule, “adsorbate”.

After filtration, which aims to retain solids in a fluid, there is no single purification process with more applications than activated carbon.
The use of activated carbon is the second most widely used separation method, second only to mechanical filtration, which puts it above more modern technologies such as membranes.

Keep reading this complete guide to know how activated carbon works, its main applications, and if you read to the end you will find a complete table with references to articles specific to each characteristic of activated carbon.
Activated carbon (coal) is a substance with a developed porous structure, high purity and large surface area, obtained by chemical or physical activation methods of plant-based materials such as wood and coconut shell.

Activated carbon (also called activated charcoal, activated coal or active carbon) is a very useful adsorbent.
Moreover, activated carbons are economical adsorbents for many industries such as water purification, food grade products, cosmetology, automotive applications, industrial gas purification, petroleum and precious metal recovery mainly for gold.

The base materials for activated carbons are coconut shell, coal or wood.
Activated carbon is a special type of carbon with a high surface area and a microporous structure.
Due to its strong adsorption capability, Activated Carbon effectively captures organic substances, volatile compounds, pollutants, and toxins, playing a crucial role in purification and filtration processes.

Activated Carbon is produced by activating carbon-based raw materials (such as wood, coal, walnut shells, or coconut shells) derived from natural and industrial sources through a specialized process.
This process, carried out at high temperatures in a controlled atmosphere, enhances the porous structure of the carbon, allowing Activated Carbon to achieve maximum adsorption capacity.

USES and APPLICATIONS of ACTIVATED CARBON:
Activated carbon has a wide range of industrial applications.
Activated Carbon is commonly used in ore recovery, water purification, air filtration, chemical processes, pharmaceutical and food production industries.

Additionally, Activated Carbon is utilized in safety equipment such as gas masks and respiratory devices to filter out harmful substances.
With its high adsorption capacity, activated carbon offers an effective solution for removing contaminants from water and air.
Therefore, Activated Carbon is an indispensable component in both industrial and domestic treatment systems.

Widely used throughout a number of industries to remove undesirable components from liquids or gases, activated carbon can be applied to an unending number of applications that require the removal of contaminants or undesirable materials, from water and air purification, to soil remediation, and even gold recovery.

Physically and chemically activated carbons, which are preferred in the food and beverage industry, are used for the removal of patulin and odor, the removal of high molecular weight colorants and proteins in liquids, as well as the removal of HMF (hydroxymethylfurfural) that causes dark color formation and various large molecules.

Activated Carbon is used for color lightening, removal of color-causing substances and purification purposes in sugar syrups obtained from sucrose obtained from sugar cane or beet, in other words, sugar and other starch derivatives such as glucose and maltose.

For the adsorption of compounds that cause undesirable taste and odor in edible oil processes and for the removal of polycyclic aromatic hydrocarbons (PAH), Activated Carbon can be used for decolorization and purification purposes, especially in the content of active ingredients of drugs such as antibiotics, antivirals and analgesics.

Due to their high surface area, pore structure (micro, meso and macro), and high degree of surface reactivity, activated carbon can be used to purify, dechlorinate, deodorize and decolorize both liquid and vapor applications.

Activated carbon is used in methane and hydrogen storage, air purification, capacitive deionization, supercapacitive swing adsorption, solvent recovery, decaffeination, gold purification, metal extraction, water purification, medicine, sewage treatment, air filters in respirators, filters in compressed air, teeth whitening, production of hydrogen chloride, edible electronics, and many other applications.

These multiuse applications make Activated Carbon a versatile form of carbon that is used daily in many industries.
Because of its large surface area and strong adsorptive capacity, activated carbon has a very wide range of uses.
Activated Carbon is extensively used in water purification, where it removes organic contaminants, chlorine, odors, and colors from drinking water, industrial wastewater, and aquaculture systems.

Activated Carbon is also used in air and gas purification to capture volatile organic compounds (VOCs), odors, and harmful emissions in industrial exhaust streams and filtration systems.
In the food and beverage industries, activated carbon helps decolorize sugar syrups, refine edible oils, and clarify beverages by adsorbing unwanted compounds that affect taste, color, or quality.

In chemical processing, Activated Carbon serves in solvent recovery and catalysis as a carrier or support due to its stable carbon structure and high surface area.
Activated Carbon also finds roles in pharmaceutical and medical applications, including in analytical chemistry for separating compounds and as an oral adsorbent to bind toxins in cases of poisoning.

Beyond these, activated carbon is used in energy storage technologies (such as supercapacitors), gas separation, metal recovery (e.g., gold adsorption in mining), and many other advanced industrial applications where adsorption of gases or dissolved substances is key.
Metals Recovery: Activated carbon is a valuable tool in the recovery of precious metals such as gold and silver.

Activated Carbon Applications: The ability to adsorb components from a liquid or gas lends itself to thousands of applications across a multitude of industries, so much so, in fact, that it would likely be easier to list applications in which activated carbon is not used.
Carbon tetrachloride activity uses of Activated carbon: Measurement of the porosity of an activated carbon by the adsorption of saturated carbon tetrachloride vapour.

Activated Carbon is used removal of volatile organic compounds such as Benzene, TCE, and PCE.
Activated Carbon is used hydrogen Sulfide (HS) and removal of waste gases
Impregnated activated carbon is used as a bacteria inhibitor in drinking water filters

Activated Carbon is used removal of taste and odor causing compounds such as MIB and geosmin
Activated Carbon is used recovery of gold
Activated Carbon is used removal of chlorine and chloramine

Designing a proper activated carbon filtration system with enough contact time, pressure drop, and vessel size is important.
Also, activated carbon’s physical and chemical characteristics play an important role in removing contaminants effectively.
Therefore, material testing is essential and ASTM test methods such as butane activity, surface area, density, and water content (moisture) can be carried out to find the best suitable material for your application.

-Particle size distribution uses of Activated carbon:
The finer the particle size of an activated carbon, the better the access to the surface area and the faster the rate of adsorption kinetics.
In vapour phase systems this needs to be considered against pressure drop, which will affect energy cost.
Careful consideration of particle size distribution can provide significant operating benefits.

However, in the case of using activated carbon for adsorption of minerals such as gold, the particle size should be in the range of 3.35–1.4 millimetres (0.132–0.055 in).
Activated carbon with particle size less than 1 mm would not be suitable for elution (the stripping of mineral from an activated carbon).

Researchers at Cornell University synthesized an ultrahigh surface area activated carbon with a BET area of 4800 m2 g–1 and a total pore volume of 2.7 cm3 g–1.
This BET area value is the highest reported in the literature for activated carbon to date.

-Chemical purification uses of Activated Carbon:
Activated carbon is commonly used on the laboratory scale to purify solutions of organic molecules containing unwanted colored organic impurities.
Filtration over activated carbon is used in large scale fine chemical and pharmaceutical processes for the same purpose.
Activated Carbon is either mixed with the solution then filtered off or immobilized in a filter.

-Mercury scrubbing uses of Activated Carbon:
Activated carbon, often infused with sulfur or iodine, is widely used to trap mercury emissions from coal-fired power stations, medical incinerators, and from natural gas at the wellhead.

However, despite its effectiveness, activated carbon is expensive to use.
Since it is often not recycled, the mercury-laden activated carbon presents a disposal dilemma.

If the activated carbon contains less than 260 ppm mercury, United States 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 from landfilling (Land-Ban Rule).

This material is now accumulating in warehouses and in deep abandoned mines at an estimated rate of 100 tons per year.
The problem of disposal of mercury-laden activated carbon is not unique to the United States.
In the Netherlands, this mercury is largely recovered and the activated carbon is disposed of by complete burning, forming carbon dioxide (CO2).

-Food additive uses of Activated Carbon:
Activated, food-grade charcoal became a food trend in 2016, being used as an additive to impart a "slightly smoky" taste and a dark coloring to products including hotdogs, ice cream, pizza bases, and bagels.
People taking medication, including birth control pills and antidepressants, are advised to avoid novelty foods or drinks that use activated charcoal coloring since Activated Carbon can render the medication ineffective.

-Smoking filtration uses of Activated Carbon:
Activated charcoal is used in smoking filters as a way to reduce the tar content and other chemicals present in smoke, which is a result of combustion, wherein it has been found to reduce the toxicants from tobacco smoke, in particular the free radicals.

-Water Purification uses of Activated Carbon:
Activated carbon can be used to pull contaminants from water, effluent or drinking, an invaluable tool in helping to protect the Earth’s most precious resource.
Water purification has a number of sub-applications, including the treatment of municipal wastewater, in-home water filters, treatment of water from industrial processing sites, groundwater remediation, and more.

-Air Purification uses of Activated Carbon:
Similarly, activated carbon can be used in the treatment of air.
This includes applications in face masks, in-home purification systems, odor reduction/removal, and the removal of harmful pollutants from flue gases at industrial processing sites.

-Industrial uses of Activated Carbon:
There are many industrial applications of activated carbon and its other forms such as areas like metal extraction, water purification, sewage treatment, metal finishing and more.

For example, Activated Carbon is the main purification technique for removing organic impurities from bright nickel plating solutions used for metal finishing plants.

Expanding on electroplating, a variety of organic chemicals can be added to the plating solutions for improving their deposit qualities and for enhancing properties like brightness, smoothness, ductility, etc.
This is due to the passage of direct current and electrolytic reactions of anodic oxidation and cathodic reduction, organic additives generate unwanted breakdown products in solution.

Their excessive build up in the solutions can adversely affect plating quality and physical properties of deposited metal if run untreated by the filters.
Activated carbon treatment removes such impurities and restores plating performance to the desired level.

Its installation costs may vary according to the volume of water it must process, however the average cost can be around USD 1 - 2 million.
Additionally, these filters need replacing over time (typically 6–12 months depending on usage).
The cost of replacing the carbon in the GAC filter form is about USD 0.05 - 0.1 per cubic meter of water that is treated in the plant.

-Examples of adsorption, 
Heterogeneous catalysis
The most commonly encountered form of chemisorption in industry, occurs when a solid catalyst interacts with a gaseous 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 not normally be available to it.

-Reactivation and regeneration: 
The reactivation or the regeneration of activated carbons involves restoring the adsorptive capacity of saturated activated carbon by desorbing adsorbed contaminants on the activated carbon surface.

-Thermal reactivation uses of Activated carbon:
The most common regeneration technique employed in industrial processes is thermal reactivation.
The thermal regeneration process generally follows three steps:

Adsorbent drying at approximately 105 °C (221 °F)
High temperature desorption and decomposition (500–900 °C (932–1,652 °F)) under an inert atmosphere

Residual organic gasification by a non-oxidising gas (steam or carbon dioxide) at elevated temperatures (800 °C (1,470 °F))
The heat treatment stage utilises the exothermic nature of adsorption and results in desorption, partial cracking and polymerization of the adsorbed organics.

The final step aims to remove charred organic residue formed in the porous structure in the previous stage and re-expose the porous carbon structure regenerating its original surface characteristics.
After treatment the adsorption column can be reused.

Per adsorption-thermal regeneration cycle between 5–15 wt% of the carbon bed is burnt off resulting in a loss of adsorptive capacity.
Thermal regeneration is a high energy process due to the high required temperatures making it both an energetically and commercially expensive process.

Plants that rely on thermal regeneration of activated carbon have to be of a certain size before it is economically viable to have regeneration facilities onsite.
As a result, it is common for smaller waste treatment sites to ship their activated carbon cores to specialised facilities for regeneration.

-Other regeneration techniques use of Activated carbon:
Current concerns with the high energy/cost nature of thermal regeneration of activated carbon has encouraged research into alternative regeneration methods to reduce the environmental impact of such processes.
Though several of the regeneration techniques cited have remained areas of purely academic research, some alternatives to thermal regeneration systems have been employed in industry.

Current alternative regeneration methods are:
TSA (thermal swing adsorption) and/or PSA (pressure swing adsorption) processes: 
through convection (heat transfer) using steam,
"hot" inert gas (typically heated nitrogen (150–250 °C (302–482 °F))),
or vacuum (T+VSA or TVSA, combining TSA and VSA processes) in situ regeneration
MWR (microwave regeneration)
Chemical and solvent regeneration
Microbial regeneration
Electrochemical regeneration
Ultrasonic regeneration
Wet air oxidation

-Application of Activated carbon:
Different types of activated carbon are suited for various specialized applications.
*Granulated activated carbon
*Pelletized activated carbon
*Powdered activated carbon
*Impregnated activated carbon
*Catalytic activated carbon

Each grade and size of activated carbon is application specific.
Selecting the correct activated carbon product and mesh size depends on the application and contaminants you plan to remove.

-Environmental uses of Activated Carbon:
Carbon adsorption has numerous applications in removing pollutants from air or water streams both in the field and in industrial processes such as:
*Spill cleanup
*Groundwater remediation
*Drinking water filtration
*Wastewater treatment
*Air purification

Volatile organic compounds capture from painting, dry cleaning, gasoline dispensing operations, and other processes
Volatile organic compounds recovery (SRU, Solvent Recovery Unit; SRP, Solvent Recovery Plant; SRS, Solvent Recovery System) from flexible packaging, converting, coating, and other processes

During early implementation of the 1974 Safe Drinking Water Act in the US, EPA officials developed a rule that proposed requiring drinking water treatment systems to use granular activated carbon.
Because of its high cost, the so-called GAC rule encountered strong opposition across the country from the water supply industry, including the largest water utilities in California.

Hence, the agency set aside the rule.
Activated carbon filtration is an effective water treatment method due to its multi-functional nature.

There are specific types of activated carbon filtration methods and equipment that are indicated – depending upon the contaminants involved.
In wastewater treatment, granulated activated carbon filters are implemented as an additional treatment step for removal of organic micropollutants such as pharmaceutical products, many of which are not entirely removed in traditional wastewater treatment processes.

Pollutants adsorb to the activated carbon granules and are then degraded by microorganisms on the filters.
Activated carbon is also used for the measurement of radon concentration in air.
Biomass waste-derived activated carbons were also successfully used for the removal of caffeine and paracetamol from water.

-Agricultural uses of Activated Carbon:
Activated carbon (charcoal) is an allowed substance used by organic farmers in both livestock production and wine making.
In livestock production, Activated Carbon is used as a pesticide, animal feed additive, processing aid, nonagricultural ingredient and disinfectant.
In organic winemaking, activated carbon is allowed for use as a processing agent to adsorb brown color pigments from white grape concentrates.
Activated Carbon is sometimes used as biochar.

-Distilled alcoholic beverage purification uses of Activated Carbon:
Activated carbon filters (AC 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 in vodka with an identical alcohol content and significantly increased organic purity, as judged by odor and taste.

-Fuel storage uses of Activated Carbon:
Research is being done testing various activated carbons' ability to store natural gas and hydrogen gas.
The porous material acts like a sponge for different types of gases.

The gas is attracted to the carbon material via Van der Waals forces.
Some carbons have been able to achieve binding energies of 5–10 kJ per mol.

The gas may then be desorbed when subjected to higher temperatures and either combusted to do work or in the case of hydrogen gas extracted for use in a hydrogen fuel cell.
Gas storage in activated carbons is an appealing gas storage method because the gas can be stored in a low pressure, low mass, low volume environment that would be much more feasible than bulky on-board pressure tanks in vehicles.

The United States Department of Energy has specified certain goals to be achieved in the area of research and development of nano-porous carbon materials.
All of the goals are yet to be satisfied but numerous institutions are continuing to conduct work in this field.

-Gas purification uses of Activated Carbon:
Filters with activated carbon are usually used in compressed air and gas purification to remove oil vapors, odor, and other hydrocarbons from the air.
The most common designs use a 1-stage or 2 stage filtration principle in which activated carbon is embedded inside the filter media.

Activated carbon filters are used to retain radioactive gases within the air vacuumed from a nuclear boiling water reactor turbine condenser.
The large charcoal beds adsorb these gases and retain them while they rapidly decay to nonradioactive solid species.
The solids are trapped in the charcoal particles, while the filtered air passes through.

-Medical uses of Activated Carbon:
Activated carbon is used to treat poisonings and overdoses following oral ingestion.
Tablets or capsules of activated carbon are used in many countries as an over-the-counter drug to treat diarrhea, indigestion, and flatulence.

However, activated charcoal shows no effect on intestinal gas and diarrhea, is ordinarily medically ineffective if poisoning resulted from ingestion of corrosive agents, boric acid, or petroleum products, and is particularly ineffective against poisonings of strong acids or bases, cyanide, iron, lithium, arsenic, methanol, ethanol, or ethylene glycol.
Activated carbon will not prevent these chemicals from being absorbed into the human body.

Activated Carbon is on the World Health Organization's List of Essential Medicines.
Incorrect application (e.g. into the lungs) results in pulmonary aspiration, which can sometimes be fatal if immediate medical treatment is not initiated.

-Analytical chemistry uses of Activated Carbon:
Activated carbon, in 50% w/w combination with celite, is used as stationary phase in low-pressure chromatographic separation of carbohydrates (mono-, di-, tri-saccharides) using ethanol solutions (5–50%) as mobile phase in analytical or preparative protocols.
Activated carbon is useful for extracting the direct oral anticoagulants (DOACs) such as dabigatran, apixaban, rivaroxaban and edoxaban from blood plasma samples.

For this purpose it has been made into "minitablets", each containing 5 mg activated carbon for treating 1ml samples of DOAC.
Since this activated carbon has no effect on blood clotting factors, heparin or most other anticoagulants this allows a plasma sample to be analyzed for abnormalities otherwise affected by the DOACs.

-Food & Beverage uses of Activated Carbon:
Activated carbon is widely used throughout the food and beverage industry to accomplish a number of objectives.
This includes decaffeination, removal of undesirable components such as odor, taste, or color, and more.

-Medicinal uses of Activated Carbon:
Activated carbon can be used to treat a variety of ailments and poisonings.
Activated carbon is an incredibly diverse material that lends itself to thousands of applications through its superior adsorbent capabilities.

MODIFICATION OF PROPERTIES AND REACTIVITY of ACTIVATED CARBON:
Acid-base, oxidation-reduction and specific adsorption characteristics are strongly dependent on the composition of the surface functional groups.
The surface of conventional activated carbon is reactive, capable of oxidation by atmospheric oxygen and oxygen plasma, steam, and also carbon dioxide and ozone.

Oxidation in the liquid phase is caused by a wide range of reagents (HNO3, H2O2, KMnO4).
Through the formation of a large number of basic and acidic groups on the surface of oxidized carbon to sorption and other properties can differ significantly from the unmodified forms.

Activated carbon can be nitrogenated by natural products or polymers or processing of carbon with nitrogenating reagents.
Activated carbon can interact with chlorine, bromine and fluorine.
Surface of activated carbon, like other carbon materials can be fluoralkylated by treatment with (per)fluoropolyether peroxide in a liquid phase, or with wide range of fluoroorganic substances by CVD-method.

Such materials combine high hydrophobicity and chemical stability with electrical and thermal conductivity and can be used as electrode material for super capacitors.
Sulfonic acid functional groups can be attached to activated carbon to give "starbons" which can be used to selectively catalyse the esterification of fatty acids.

Formation of such activated carbons from halogenated precursors gives a more effective catalyst which is thought to be a result of remaining halogens improving stability.
It is reported about synthesis of activated carbon with chemically grafted superacid sites –CF2SO3H.
Some of the chemical properties of activated carbon have been attributed to presence of the surface active carbon double bond.
The Polyani adsorption theory is a popular method for analyzing adsorption of various organic substances to their surface.

ESSENTIAL FOR EFFECTIVE WATER TREATMENT ACROSS INDUSTRIES of ACTIVATED CARBON:
Activated carbon is a highly effective and indispensable solution for various water treatment applications, including:

*Drinking water treatment: 
Ensuring safe and clean drinking water by removing contaminants and impurities.

*Food and beverage production: 
Purifying water to a degree that is compliant with strict industry requirements for safe production of various foods and beverages.

*Service water treatment: 
Enhancing the quality of water used in various industrial processes, such as chemicals production, pharmaceuticals, odor control, biogas, and steam generation.

*Removal of harmful substances: 
Proven technology for removal of PFAS and other micropollutants from drinking water, waste water, and landfill leachate.

STRUCTURE of ACTIVATED CARBON:
The structure of activated carbon has long been a subject of debate.
In a book published in 2006, Harry Marsh and Francisco Rodríguez-Reinoso considered more than 15 models for the structure, without coming to a definite conclusion about which was correct.

Recent work using aberration-corrected transmission electron microscopy has suggested that activated carbons may have a structure related to that of the fullerenes, with pentagonal and heptagonal carbon rings.

Activated carbon is made by causing a carbon-based substance, such as coconut shells or coal, to react with a gas or chemical at high temperatures.
It has micropores ranging from 10 to 200Å (10Å = 1nm) in diameter.

Kuraray began producing activated carbon under the brand name KURARAY COAL in 1965.
The micropores of the activated carbon form a meshwork structure inside the carbon, so the micropore walls have a large surface area (500–2500m2/g), and various substrates can be adsorbed on the surface.

WHAT ARE THE MAIN FORMS OF ACTIVATED CARBON?
Not all activated carbon is the same and so the selection of the appropriate raw material, product form and properties is critical for each application.
Activated carbon or activated charcoal comes in many different forms which are primarily in the form of a granular product, an extruded product or as a powder.

***GRANULAR ACTIVATED CARBON (GAC)
Granular activated carbon is an irregularly shaped particle crushed from its raw material form and then sized to specific mesh sizes.
These sizes typically range from 0.2mm to 5 mm.
The main sizes range from the coarser US mesh sizes of 4×8, 6×12, and 8×16, to the finer sizes of 8×30, 12×20, 12×40, 20×50 US mesh sizes.

They can be produced from any carbon-based feedstock.
The adsorptive capacity of GAC makes it ideal for removing contaminants from water, air, liquids, and gases.
Typically, granular activated carbons are placed in a filter bed in a steel or concrete vessel.

In water or liquid applications, the liquid typically flows downwards through the carbon filter bed by gravity.
For air, vapour or gas processes, the air or gas typically flows upwards through the carbon bed.

When granular carbon can no longer adsorb any more material, it is considered exhausted or spent.
This spent granular carbon has the advantage that it can be recycled by thermal reactivation for reuse multiple times and returned to customers for reuse, instead of disposal.

***PELLETS OR EXTRUDED ACTIVATED CARBONS
Pellets are produced by compressing or extruding the activated carbon into formed cylinders.
They generally have diameters ranging from 0.8 mm to 5 mm, with typical sizes of 3 mm and 4mm.

They are predominantly produced from coal but also from coconut-based feedstocks.
The production process gives them high mechanical strength, uniformity of shape, and low dust content, making them more appropriate for removing contaminants from air and gas streams.

Pellets are typically used for air and gas purification applications as low-pressure drops tend to be more crucial for these applications.
Pelletised carbons operate similarly to granular activated carbons in a carbon filter bed where the air or gas passes through it.
Pellets can also be recycled by thermal reactivation for reuse multiple times for the same application.

***POWDER ACTIVATED CARBONS (PAC)
Powder activated carbons are produced by pulverising a granular activated carbon feedstock or from fines generated during activated carbon production.

Powder carbons have a size predominantly less than 0.045 mm or 45 microns (<325 US Mesh) and they can be produced from any carbon-based feedstock.

The use of powder activated carbons tends to differ from that of granular or pelletised carbons.
They are typically applied in batch operations by dosing or added into a water or gas stream and are filtered out later after use.
In the liquid phase, this is mostly in batch operations, where the powder dosage can be adjusted to suit the particular requirement.

***ACTIVATED CARBON CLOTH
Activated carbon can also be produced in the form of a cloth or textile which can be in a woven or knitted form.
This form of activated carbon has a microporous structure and is 100% activated carbon.
Carbon cloth tends to be used in more specialised applications such as in medical or specialised clothing applications.

***IMPREGNATED ACTIVATED CARBONS
Certain compounds have a low adsorption capacity on the base activated carbon.
Therefore, to enhance the carbons performance, finely distributed chemical solutions can be selectively added to the carbon surface to generate impregnated activated carbons.

They are typically in pellet or granular form and are predominantly produced from coal and coconut-based feedstocks.
Impregnated carbons are primarily used in air or gas phase applications and usually for the removal of hazardous contaminants.
The chemical impregnants that have been incorporated into the carbon can neutralize the adsorbed contaminants through a chemical reaction at its surface.

HOW IS ACTIVATED CARBON MADE?
There are several different ways to produce activated carbon, depending on the raw material.
Chemical Activation – typically applied to wood-based feedstocks.
Physical Activation.
Direct Activation method.
Agglomeration or, more correctly, the reagglomeration method.

For chemical activation, the dried wood based raw material is first treated with an acid, typically phosphoric acid and then thermally activated in a kiln.
The resulting product is then washed to remove any remaining acid from the carbon.

For the direct activation method, any volatile organic content of the raw material is removed during a baking or carbonising stage to produce a char or charcoal.
This char is then thermally activated in a furnace and screened to generate the final activated carbon.

REAGGLOMERATED ACTIVATED CARBONS
Reagglomerated activated carbons are also produced by a multistage process.
This involves the initial pulverisation of the raw material and then the addition of pitch as a binder, to produce briquettes.
This is the agglomeration step.

These briquettes are then crushed and sieved to obtain granules suitable for the next steps.
These granules are then baked which involves oxidation + carbonisation.

They are then passed through the high temperature activation furnace, which selectively burns away part of the structure to generate these agglomerated activated carbons.
Finally, the carbon is screened to produce the finished product.

Prime grades of granular activated carbons, are produced by this reagglomeration process from selected grades of bituminous coal.
This process produces an activated carbon that is uniformly and highly activated throughout the whole granule.
This agglomeration process results in activated carbons with excellent adsorption properties and constant adsorption kinetics.

The re-agglomeration step generates granular carbons that are highly durable.
This means that they are capable of withstanding the abrasion associated with repeated backwashing and hydraulic transfers, particularly associated with water process applications.
The re-agglomerated structure also ensures a fast and effective wetting of the activated carbon when put into water or solution whilst eliminating any floating material.

This re-agglomeration process ensures that these carbons are designed for multiple reactivations where they can be recycled for reuse whilst retaining their operational properties.

TYPES OF ACTIVATED CARBON
*COCONUT BASED ACTIVATED CARBONS
Granular Activated Carbon
Powdered Activated Carbon
Pellet Activated Carbon

*COAL BASED ACTIVATED CARBONS
Granular Activated Carbon
Powdered Activated Carbon
Pellet Activated Carbon

*WOOD BASED ACTIVATED CARBONS
Granular Activated Carbon
Powdered Activated Carbon
Pellet Activated Carbon

*IMPREGNATED CARBONS
Granular Activated Carbon
Pellet Activated Carbon

*HONEYCOMB CARBONS
Normal Type Honeycomb Carbon
Waterproof Type Honeycomb Carbon

PRODUCTION of ACTIVATED CARBON:
Activated carbon is carbon produced from carbonaceous source materials such as bamboo, coconut husk, willow peat, wood, coir, lignite, coal, and petroleum pitch.
Activated Carbon can be produced (activated) by one of the following processes:

*Physical activation:
The source material is developed into activated carbon using hot gases.
Air is then introduced to burn out the gases, creating a graded, screened and de-dusted form of activated carbon.
This is generally done by using one or more of the following processes:

*Carbonization:
Material with carbon content is pyrolyzed at temperatures in the range 600–900 °C, usually in an inert atmosphere with gases such as argon or nitrogen.

*Activation/oxidation:
Raw material or carbonized material is exposed to oxidizing atmospheres (oxygen or steam) at temperatures above 250 °C, usually in the temperature range of 600–1200 °C.
The activation is performed by heating the sample for 1 h in a muffle furnace at 450 °C in the presence of air.

*Chemical activation:
Activated Carbon is impregnated with certain chemicals.
The chemical is typically an acid, strong base, or a salt (phosphoric acid 25%, potassium hydroxide 5%, sodium hydroxide 5%, potassium carbonate 5%, calcium chloride 25%, and zinc chloride 25%).

The carbon is then subjected to high temperatures (250–600 °C).
It is believed that the temperature activates Activated Carbon at this stage by forcing the material to open up and have more microscopic pores.
Chemical activation is preferred to physical activation owing to the lower temperatures, better quality consistency, and shorter time needed for activating the material.

REGENERATION & SUSTAINABILITY of ACTIVATED CARBON:
After adsorption, spent granular activated carbon can often be regenerated rather than discarded.
Thermal reactivation (heating in an inert or steam atmosphere at 800–900 °C) restores much of the pore structure but consumes significant energy, while chemical regeneration (e.g. with dilute acids or bases) can selectively remove fouling compounds under milder conditions.

Emerging methods like microwave-assisted reactivation and bio-regeneration using fungi or bacteria show promise for lower-carbon footprints.
Choosing the optimal regeneration route balances carbon lifespan, energy use and treatment costs, and helps minimize the volume of hazardous waste sent to landfill.

CLASSIFICATION of ACTIVATED CARBON:
Activated carbons are complex products which are difficult to classify on the basis of their behaviour, surface characteristics and other fundamental criteria.
However, some broad classification is made for general purposes based on their size, preparation methods, and industrial applications.

Powdered activated carbon (PAC)
Normally, activated carbons are made in particulate form as powders or fine granules less than 1.0 mm in size with an average diameter between 0.15 and 0.25 mm.
Thus they present a large surface to volume ratio with a small diffusion distance.
Activated carbon is defined as the activated carbon particles retained on a 50-mesh sieve (0.297 mm).

Powdered activated carbon (PAC) material is finer material.
PAC is made up of crushed or ground carbon particles, 95–100% of which will pass through a designated mesh sieve.
The ASTM classifies particles passing through an 80-mesh sieve (0.177 mm) and smaller as PAC.
It is not common to use PAC in a dedicated vessel, due to the high head loss that would occur.
Instead, PAC is generally added directly to other process units, such as raw water intakes, rapid mix basins, clarifiers, and gravity filters.

KEY BENEFITS INCLUDE ACTIVATED CARBON:
*Wastewater treatment
Systematic treatment of individual effluent streams, especially in the chemicals industry.

*Biological wastewater treatment
Removing substances toxic to bacteria, thereby improving the efficiency of biological treatment processes.

*Tertiary wastewater treatment
Meeting stringent effluent restrictions by providing an additional layer of purification.

*Landfill seepage treatment
Addressing the complex challenges of treating landfill leachate.

BENEFITS AND KEY CHARACTERISTICS of ACTIVATED CARBON:
The primary benefit of activated carbon lies in its exceptional adsorption capability, which enables it to remove a wide spectrum of contaminants from gases and liquids.
Its high surface area and porosity allow activated carbon to be tailored for specific applications by controlling the activation process and pore size distribution.

This means Activated Carbon can be optimized for capturing very small molecules, large organic compounds, or specific contaminants in complex mixtures.

Activated carbon’s versatility is unmatched by many other filtration media, and its performance can be enhanced further through chemical modification or impregnation with specific agents to target certain pollutants.
Its stability, relatively low cost, and adaptability make Activated Carbon fundamental in both large-scale industrial processes and smaller consumer applications like home water filters and respirator cartridges.

KEY FUNCTIONAL CHARACTERISTICS of ACTIVATED CARBON:
*Extremely high adsorption capacity
*Large internal pore volume
*Selective adsorption depending on pore size distribution
*Chemically inert toward most acids, bases, and salts at room temperature
*Can be regenerated by thermal or chemical methods
*Environmentally persistent but non-volatile

GRANULAR ACTIVATED CARBON (GAC):
Granular activated carbon (GAC) 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 suitable for adsorption of gases, vapors and liquids, because these substances diffuse rapidly throughout the filters.
Granulated carbons are used for air filtration and water treatment, as well as for general deodorization and separation of components in flow systems and in rapid mix basins.

GAC can be obtained in either granular or extruded form.
GAC is designated by sizes such as 8×20, 20×40, or 8×30 for liquid phase applications and 4×6, 4×8 or 4×10 for vapor phase applications.
A 20×40 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 U.S. Standard Mesh Size No. 40 sieve (0.42 mm) (generally specified as 95% retained).

AWWA (1992) B604 uses the 50-mesh sieve (0.297 mm) as the minimum GAC size.
The most popular aqueous-phase carbons are the 12×40 and 8×30 sizes because they have a good balance of size, surface area, and head loss characteristics.

EXTRUDED ACTIVATED CARBON (EAC):
Extruded activated carbon (EAC) combines powdered activated carbon with a binder, which are fused together and extruded into a cylindrical shaped activated carbon block with diameters from 0.8 to 130 mm.
These are mainly used for gas phase applications because of their low pressure drop, high mechanical strength and low dust content.
Also sold as CTO filter (Chlorine, Taste, Odor).

BEAD ACTIVATED CARBON (BAC):
Bead activated carbon (BAC) is manufactured from carbonizing petroleum pitch and then activating it into uniform spheres in diameters from approximately 0.35 to 0.80 mm.
BAC typically exhibits a surface area in the range of 800–1 200 m2/g, comparable to or exceeding many granular carbons, enhancing its capacity for dissolved organics.
Similar to EAC, it is also noted for its low pressure drop, high mechanical strength and low dust content, but with a smaller grain size.
Its spherical shape makes it preferred for fluidized bed applications such as water filtration.

IMPREGNATED CARBON:
Porous carbons containing several types of inorganic impregnate such as iodine and silver.
Cations such as aluminium, manganese, zinc, iron, lithium, and calcium have also been prepared for specific application in air pollution control especially in museums and galleries.
Due to its antimicrobial and antiseptic properties, silver loaded activated carbon is used as an adsorbent for purification of domestic water.

Drinking water can be obtained from natural water by treating the natural water with a mixture of activated carbon and aluminium hydroxide (Al(OH)3), a flocculating agent.
Impregnated carbons are also used for the adsorption of hydrogen sulfide (H2S) and thiols.
Adsorption rates for H2S as high as 50% by weight have been reported.

POLYMER COATED CARBON:
This is a process by which a porous carbon can be coated with a biocompatible polymer to give a smooth and permeable coat without blocking the pores.
The typical film thickness ranges from 50 to 200 nm, which strikes a balance between preserving pore access and ensuring mechanical stability in the material.
The resulting carbon is useful for hemoperfusion.

Hemoperfusion is a treatment technique in which large volumes of the patient's blood are passed over an adsorbent substance in order to remove toxic substances from the blood.
In clinical trials, polymer-coated carbons have achieved over 80% removal of toxins such as bilirubin and certain drug metabolites in a single pass.

WOVEN CARBON:
There is a technology of processing technical rayon fiber into activated carbon cloth for carbon filtering.
Adsorption capacity of activated cloth is greater than that of activated charcoal (BET theory) surface area: 500–1500 m2/g, pore volume: 0.3–0.8 cm3/g).
Thanks to the different forms of activated material, it can be used in a wide range of applications (supercapacitors, odor absorbers, CBRN-defense industry etc.).

WHAT IS THE STRUCTURE OF ACTIVATED CARBON?
Activated carbon is composed of a random, imperfect structure of graphite platelets and is essentially a crude form of graphite, the material used for pencil leads.

This structure resembles a deck of well-used playing cards.
This imperfect arrangement of platelets, connected by carbon-carbon bonds, creates a highly porous structure.

This structure has a broad range of pore sizes from visible cracks and crevices down to molecular scale pores.
The picture above illustrates the graphitic plate structure of activated carbon at a very high magnification.

This graphitic platelet structure gives activated carbon its very high internal surface area.
Activated carbon can have a surface area greater than 1000 m²/g.

This means that only 5 gm of activated carbon has an internal surface area equivalent to a football field.
This surface area enables activated carbon to adsorb various organic compounds from air, gases, and liquids.

WHAT IS ACTIVATED CARBON MADE FROM?
Activated carbon can be made really from any carbon-containing starting material.
However, the main requirement for a cost-effective product is that the raw material should have a high carbon content and be easy to source.

The most commonly used raw materials are bituminous coal, wood, coconut shells, lignite and peat.
The raw material selection is an important parameter as it will dictate the uniqueness of the final activated carbon.

Activated carbon inherits properties from the original raw material and will dictate the uniqueness of the product and its adsorption capabilities.
These are ash impurities, density, hardness or abrasion resistance and the transport pore structure which affects its performance kinetics.

The raw material selection, quality and the process to convert the carbon-containing feedstock into activated carbon, all have a significant influence on the final product properties.
For example, bituminous coal and coconut based activated carbons have different physical properties and characteristics that provide performance advantages in different applications.

PROPERTIES of ACTIVATED CARBON:
A gram of activated carbon can have a surface area in excess of 500 m2 (5,400 sq ft), with 3,000 m2 (32,000 sq ft) being readily achievable.
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 particles are intensely convoluted and display various kinds of porosity; there may be many areas where flat surfaces of graphite-like material run parallel to each other, separated by only a few nanometres or so.
These micropores provide superb 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 terms activated carbon is perfectly capable of producing the equivalent, by adsorption from its environment, liquid water from steam at 100 °C (212 °F) and a pressure of 1/10,000 of an atmosphere.

James Dewar, the scientist after whom the Dewar (vacuum flask) is named, spent much time studying activated carbon and published a paper regarding its adsorption capacity with regard to gases.
In this paper, he discovered that cooling the carbon to liquid nitrogen temperatures allowed it to adsorb significant quantities of numerous air gases, among others, that could then be recollected by simply allowing the carbon to warm again and that coconut-based carbon was superior for the effect.

He uses oxygen as an example, wherein the activated carbon would typically adsorb the atmospheric concentration (21%) under standard conditions, but release over 80% oxygen if the carbon was first cooled to low temperatures.
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, diols, strong acids and bases, metals and most inorganics, such as lithium, sodium, iron, lead, arsenic, fluorine, and boric acid.
Activated carbon can also adsorb iodine very well.

The iodine capacity, mg/g, (ASTM D28 Standard Method test) may be used as an indication of total adsorption over the surface area of the testing material.
Carbon monoxide however, is not very well adsorbed by activated carbon.

This should be of particular concern to those using the material in filters for respirators, fume hoods, or other gas control systems because the gas is undetectable to the human senses, toxic to the metabolism, and neurotoxic which creates concern.
Substantial lists of the common industrial and agricultural gases adsorbed by activated carbon can be found online.

Activated carbon can be used as a substrate for the application of various chemicals to improve the adsorptive capacity for some inorganic (and problematic organic) compounds such as hydrogen sulfide (H2S), ammonia (NH3), formaldehyde (HCOH), mercury (Hg) and radioactive iodine-131 (131I).
This property is known as chemisorption.

***Iodine number
Many carbons preferentially adsorb small molecules.
Iodine number is the most fundamental parameter used to characterize activated carbon performance.
Activated Carbon is a measure of activity level (higher number indicates higher degree of activation) often reported in mg/g (typical range 500–1200 mg/g).

It is a measure of the micropore content of the activated carbon (0 to 20 Å, or up to 2 nm) by adsorption of iodine from solution.
Activated Carbon is equivalent to surface area of carbon between 900 and 1100 m2/g.

Activated Carbon 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 concentration in the residual filtrate is at a concentration of 0.02 normal (i.e. 0.02N).

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-treatment carbons have iodine numbers ranging from 600 to 1100.

Frequently, this parameter is used to determine the degree of exhaustion of a carbon in use.
However, this practice should be viewed with caution, as chemical interactions with the adsorbate may affect the iodine uptake, giving false results.

Thus, the use of iodine number as a measure of the degree of exhaustion of a carbon bed can only be recommended if it has been shown to be free of chemical interactions with adsorbates and if an experimental correlation between iodine number and the degree of exhaustion has been determined for the particular application.

***Molasses
Some carbons are more adept at adsorbing large molecules.
Molasses number or molasses efficiency is a measure of the mesopore content of the activated carbon (greater than 20 Å, or larger than 2 nm) by adsorption of molasses from solution.

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 (range 40%–185%) and parallels molasses number (600 = 185%, 425 = 85%).

The European molasses number (range 525–110) 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 diluted and standardized against standardized activated carbon.

Due to the size of color bodies, the molasses number represents the potential pore volume available for larger adsorbing species.
As all of the pore volume may not be available for adsorption in a particular waste water application, and as some of the adsorbate may enter smaller pores, it is not a good measure of the worth of a particular activated carbon for a specific application.

Frequently, this parameter is useful in evaluating a series of active carbons for their rates of adsorption.
Given two active carbons with similar pore volumes for adsorption, the one having the higher molasses number will usually have larger feeder pores resulting in more efficient transfer of adsorbate into the adsorption space.

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

***Methylene blue
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.
Methylene blue adsorption is reported in g/100g (range 11–28 g/100g).

***Dechlorination
Some carbons are evaluated based on the dechlorination half-life length, which measures the chlorine-removal efficiency of activated carbon.
The dechlorination half-value length is the depth of carbon required to reduce the chlorine concentration by 50%.
A lower half-value length indicates superior performance.

***Apparent density
The solid or skeletal density of activated carbons will typically range between 2000 and 2100 kg/m3 (125–130 lbs./cubic foot).
However, a large part of an activated carbon sample will consist of air space between particles, and the actual or apparent density will therefore be lower, typically 400 to 500 kg/m3 (25–31 lbs./cubic foot).
Higher density provides greater volume activity and normally indicates better-quality activated carbon.
ASTM D 2854 -09 (2014) is used to determine the apparent density of activated carbon.

***Hardness/abrasion number
It is a measure of the activated carbon's resistance to attrition.
It is an important indicator of activated carbon to maintain its physical integrity and withstand frictional forces which would cause the material to be defective.
There are large differences in the hardness of activated carbons, depending on the raw material and activity levels (porosity) it is created for.

***Ash content
Ash reduces the overall activity of activated carbon and reduces the efficiency of reactivation.
The amount is exclusively dependent on the base raw material used to produce the activated carbon (e.g., coconut, wood, coal, etc.).
The metal oxides (Fe2O3) can leach out of activated carbon resulting in discoloration.
Acid/water-soluble ash content is more significant than total ash content.

Soluble ash content can be very important for aquarists, as ferric oxide can promote algal growths.
A carbon with a low soluble ash content should be used for marine, freshwater fish and reef tanks to avoid heavy metal poisoning and excess plant/algal growth.
ASTM (D2866 Standard Method test) is used to determine the ash content of activated carbon.

PHYSICAL AND CHEMICAL PROPERTIES of ACTIVATED CARBON:
Activated carbon typically appears as a black, lightweight powder or as granular or pelletized forms, depending on its intended application.
Activated Carbon is practically insoluble in all common solvents and consists almost entirely of carbon with trace quantities of other elements depending on the source and activation process.

Activated Carbon’s most defining characteristic is its extremely high internal surface area resulting from a complex network of micropores, mesopores, and macropores.

A typical activated carbon product may exhibit surface areas exceeding several thousand square meters per gram when measured using gas adsorption techniques.
This extensive porosity makes activated carbon extraordinarily effective at trapping a wide variety of molecules from gases or liquids.

Physically, activated carbon is a very fine powder or granular solid with a low bulk density compared to non-activated carbon.
Activated Carbon is non-graphitic in many commercial forms, meaning its inner structure lacks the highly ordered graphite crystal planes found in pure graphite, but instead comprises a more amorphous, irregular carbon network.

ACTIVATION AND MANUFACTURING of ACTIVATED CARBON:
Activated carbon is produced by subjecting a carbonaceous precursor (e.g., wood, coconut shells, peat, or coal) to high temperatures in the absence of air (carbonization) followed by an activation step.
Activation can be done physically, by introducing oxidizing gases such as steam or carbon dioxide at high temperatures, or chemically, by impregnating the carbonized material with activating agents (e.g., phosphoric acid or potassium hydroxide) before heating.
These steps greatly increase the pore volume and surface area compared to raw charcoal.

TYPES of ACTIVATED CARBON:
***Coconut shell-based activated carbon
The very large internal surface areas characterized by microporosity along with high hardness and low dust make these coconut shell carbons particularly attractive for water and critical air applications as well as point-of-use water filters and respirators

*Very high surface area characterized by a large proportion of micropores
*High hardness with low dust generation
*Excellent purity, with most products exhibiting no more than 3-5% ash content.
*Renewable and green raw material.
*More about Coconut shell activated carbon

***Coal-based activated carbon
Demand is typically high for this relatively low cost filter media for both gas and liquid applications.
Coal based activated carbon has a high surface area characterized by both mesopores and micropores.

*Consistent density
*Hard materials with minimal dust generation.
*Economical
*More about Coal based activated carbon

***Wood based activated carbon
It produces different performance characteristics in industrial applications typically catered to with coal or coconut products.
Wood based activated carbon has a high surface area characterized by both mesopores and micropores and has excellent decolorizing properties owing to its signature porosimetry

*Relatively low density
*Renewable source of raw material
*More about Wood based activated carbon

***Catalytic based activated carbon
Catalytic carbon is a class of activated carbon used to remove chloramines and hydrogen sulfide from drinking water.
It has all the adsorptive characteristics of conventional activated carbons, as well as the ability to promote chemical reactions.

Catalytic carbon is not impregnated with caustic chemicals
Because catalytic carbons have no impregnates, you won’t have to worry about reduced organic odor capacity or the higher bed fire potential of the impregnated carbons.

Catalytic carbon is created by altering the surface structure of activated carbon.
It is modified by gas processing at high temperatures to change the electronic structure and create the highest level of catalytic activity on carbon for reducing chloramine and H2S in water.
This added catalytic functionality is much greater than that found in traditional activated carbons.

Catalytic carbon is an economical solution to treat H2S levels as high as 20 to 30 ppm.
Catalytic carbon converts adsorbed H2S into sulfuric acid and sulfurous acid which are water soluble, so carbon systems can be regenerated with water washing to restore H2S capacity for less frequent physical change-outs.

***Impregnated Activated Carbon
Surface impregnation chemically modifies activated carbon through a fine distribution of chemicals and metal particles on the internal surfaces of its pores.
This greatly enhances the carbon’s adsorptive capacity through a synergism between the chemicals and the carbon.
And provides a cost-effective way to remove impurities from gas streams which would otherwise not be possible.

Water treatment
Because of its antimicrobial/antiseptic properties, silver-impregnated carbon is an effective adsorbent for purification in earth-bound domestic and other water systems.

Gas purification
Impregnated activated carbon is used to treat flue gases in coal-fired generation plants and other air pollution control applications.
Carbon can be specifically impregnated for removal of acid gases, ammonia and amines, aldehydes, radio-active iodine, mercury and inorganic gases such as arsine and phosphine.
Carbon impregnated with metal-oxide targets inorganic gases including HCN, H2S, phosphine and arsine.

HOW DOES ACTIVATED CARBON WORK AND WHAT ARE ITS BENEFITS?
Activated Carbon is an adsorption media, its function is to adsorb organic molecules within its micro pores for liquids and gases purification It is activated by thermal or chemical processes to enhance its adsorption capacity (to make pores form).
Activated carbon has the ability to adsorb.

So, some people put charcoal in the refrigerator to get rid of bad odors.
The same happens when you put charcoal in a bucket of water.
Eliminates color, taste and odor.
Or, in the countryside, people burn and eat tortillas to relieve digestive problems (mild infections, indigestion, bloating, etc.).

Activated carbon involves making it porous to increase its absorbency.
One gram of charcoal has a surface area of about 50 square meters.
With activation, Activated Carbon reaches 600 to 800 m2, i.e., a 12 to 16-fold increase.

WHAT IS ACTIVATED CARBON USED FOR?
Water purification.
(carbon retains pesticides, greases, oils, detergents, disinfection by-products, toxins, color-producing compounds, compounds originating from the decomposition of algae and plants or from animal metabolism…).

Deodorization and air purification.
For example: in cartridge respirators, air recirculation systems in public spaces, drain vents and water treatment plants, paint application booths, spaces that store or apply organic solvents.

Treatment of people with acute intoxication.
Activated charcoal is considered the “most universal antidote”, and is applied in emergency rooms and hospitals.

Sugar refining.
The charcoal retains the proteins that give color to the cane juice; the fundamental objective of this process is to prevent the sugar from fermenting and spoiling.

Discoloration of vegetable oils.
(such as coconut).
Corn glucose and other liquids intended for food.
Discoloration and deodorization of alcoholic beverages.
(such as grape wines and distillates of any origin)

Gold recovery.
Gold that cannot be separated from minerals by flotation processes is dissolved in sodium cyanide and adsorbed on activated carbon.

PROPERTIES of ACTIVATED CARBON:
When selecting an activated carbon for a particular application, a variety of characteristics should be considered:

*Pore Structure
The pore structure of activated carbon varies and is largely a result of the source material and the method of production.
The pore structure, in combination with attractive forces, is what allows adsorption to occur.

*Hardness/Abrasion
Hardness/abrasion is also a key factor in selection.
Many applications will require the activated carbon to have a high particle strength and a resistance to attrition (the breakdown of material into fines).
Activated carbon produced from coconut shells has the highest hardness of activated carbons.

*Adsorptive Properties
The absorptive properties of the activated carbon encompass several characteristics, including adsorptive capacity, the rate of adsorption, and the overall effectiveness of activated carbon.
Depending on the application (liquid or gas), these properties may be indicated by a number of factors, including the iodine number, surface area, and Carbon Tetrachloride Activity (CTC).

*Apparent Density
While apparent density will not affect the adsorption per unit weight, it will affect the adsorption per unit volume.

*Moisture
Ideally, the amount of physical moisture contained within the activated carbon should fall within 3-6%.

*Ash Content
The ash content of activated carbon is a measure of the inert, amorphous, inorganic, and unusable part of the material.
The ash content will ideally be as low as possible, as the quality of the activated carbon increases as ash content decreases.

*pH Value
The pH value is often measured to predict potential change when activated carbon is added to liquid.

*Particle Size
Particle size has a direct effect on adsorption kinetics, flow characteristics, and filterability of the activated carbon.
Activated Carbon Production
Activated carbon is produced through two main processes: carbonization and activation.

*Carbonization
During carbonization, the raw material is thermally decomposed in an inert environment, at temperatures below 800 ºC.
Through gasification, elements such as oxygen, hydrogen, nitrogen, and sulfur, are removed from the source material.

*Activation
The carbonized material, or char, must now be activated to fully develop the pore structure.
This is done through oxidizing the char at temperatures between 800-900 ºC in the presence of air, carbon dioxide, or steam.

Depending on the source material, the process of producing activated carbon can be carried out using either thermal (physical/steam) activation, or chemical activation.
In either case, a rotary kiln can be used to process the material into an activated carbon.

*Activated Carbon Reactivation
One of the many advantages to activated carbon is its ability to be reactivated.
While not all activated carbons are reactivated, those that are provide cost savings in that they do not require the purchase of fresh carbon for each use.

Regeneration is typically carried out in a rotary kiln and involves the desorption of the components that had previously been adsorbed by the activated carbon.
Once desorbed, the once-saturated carbon is again considered active and ready to act as an adsorbent again.

Activated carbon is a powerful and versatile solution for a wide array of water treatment applications, known for its ability to remove contaminants such as PFAS, and purify water across industries.
From ensuring safe drinking water to supporting industrial processes like food production and wastewater management, its unique properties make it essential.

PHYSICAL and CHEMICAL PROPERTIES of ACTIVATED CARBON:
Appearance: Black solid
Physical form: Powder, granular, pelletized, or extruded forms
Odor: Odorless
Taste: Tasteless
Bulk density: Low bulk density compared to non-activated carbon (varies by grade)
True density: Approximately 1.8–2.1 g/cm³
Surface area: Very high, typically 500–2000 m²/g (BET method), depending on activation method
Porosity: Highly porous structure with micro-, meso-, and macropores

Particle size: Variable (micron-scale powders to millimeter-scale granules)
Color: Deep black
Hygroscopicity: Slightly hygroscopic
Electrical conductivity: Low to moderate (depends on graphitization level)
CAS Number: 7440-44-0
EC (EINECS) Number: 231-153-3
Molecular Formula: C

Molecular Weight (Atomic Weight): 12.01 g/mol
Chemical nature: Elemental carbon (amorphous to partially graphitic)
Solubility in water: Insoluble
Solubility in organic solvents: Insoluble
pH (aqueous slurry): Typically neutral to slightly alkaline (pH ~6–9, grade-dependent)
Reactivity: Chemically stable under normal conditions
Oxidation resistance: Stable at ambient temperature; oxidizes at high temperatures in air

Combustibility: Combustible solid
Flammability: Not flammable as a solid block, but carbon dust may form explosive mixtures with air
Thermal stability: High; withstands elevated temperatures in inert atmosphere
Adsorption behavior: Strong physical adsorption via van der Waals forces
Chemical adsorption: Possible when surface-modified or impregnated
Catalytic behavior: Can act as catalyst support
Reducing properties: Mild reducing behavior at elevated temperatures

FIRST AID MEASURES of ACTIVATED CARBON:
-Description of first-aid measures
*General advice:
Show this material safety data sheet to the doctor in attendance.
*If inhaled:
After inhalation: 
Fresh air.
*In case of skin contact: 
Take off immediately all contaminated clothing. 
Rinse skin with
water/ shower.
*In case of eye contact:
After eye contact: 
Rinse out with plenty of water. 
Call in ophthalmologist. 
Remove contact lenses.
*If swallowed:
After swallowing: 
Immediately make victim drink water (two glasses at most). 
Consult a physician.
-Indication of any immediate medical attention and special treatment needed.
No data available

ACCIDENTAL RELEASE MEASURES of ACTIVATED CARBON:
-Environmental precautions:
Do not let product enter drains.
-Methods and materials for containment and cleaning up:
Cover drains. 
Collect, bind, and pump off spills. 
Observe possible material restrictions. 
Take up dry. 
Dispose of properly. 
Clean up affected area.

FIRE FIGHTING MEASURES of ACTIVATED CARBON:
-Extinguishing media:
*Suitable extinguishing media:
Carbon dioxide (CO2) 
Foam 
Dry powder
*Unsuitable extinguishing media:
For this substance/mixture no limitations of extinguishing agents are given.
-Further information:
Prevent fire extinguishing water from contaminating surface water or the ground water system.

EXPOSURE CONTROLS/PERSONAL PROTECTION of ACTIVATED CARBON:
-Control parameters:
--Ingredients with workplace control parameters:
-Exposure controls:
--Personal protective equipment:
*Eye/face protection:
Use equipment for eye protection. 
Safety glasses
*Body Protection:
protective clothing
*Respiratory protection:
Recommended Filter type: Filter A 
-Control of environmental exposure:
Do not let product enter drains.

HANDLING and STORAGE of ACTIVATED CARBON:
-Conditions for safe storage, including any incompatibilities:
*Storage conditions:
Tightly closed. 
Dry.

STABILITY and REACTIVITY of ACTIVATED CARBON:
-Chemical stability:
The product is chemically stable under standard ambient conditions (room temperature).
-Possibility of hazardous reactions:
No data available