Activated Carbon: Organic Pollutants And Beyond

Activated carbon, also known as activated charcoal, is a highly porous substance used to absorb and retain organic compounds and some inorganic compounds. It is created by burning carbon-rich substances, resulting in carbon char, which then undergoes chemical or physical treatment to create a network of pores within the carbon. The large surface area and pore size of activated carbon make it an effective adsorbent for removing pollutants from air and water, such as volatile organic compounds (VOCs), odours, and harmful gases. It is also used in medical applications to treat drug overdoses and poisonings. While activated carbon has a wide range of applications, its effectiveness depends on various factors such as the type of carbon, the pollutant intended to be removed, and the degree of purity desired.

Activated carbon is used to treat poisonings and remove pollutants from air or water

Activated carbon is a versatile substance with a range of applications, particularly in treating poisonings and removing pollutants from air and water. Its effectiveness stems from its unique structure, which includes a network of pores that give it an exceptionally high surface area. This porous structure enables activated carbon to adsorb, or attract and retain, various compounds and pollutants.

Activated carbon is widely used to remove pollutants from water, a process known as water treatment or purification. One common type of activated carbon used for this purpose is granular activated carbon (GAC), which effectively removes organic pollutants, chlorine, and unpleasant odours from drinking water, significantly improving water quality. For example, drinking water can be obtained from natural water by treating it with a mixture of activated carbon and aluminium hydroxide, a flocculating agent.

The adsorption properties of activated carbon also make it useful for air purification or air pollution control. It can effectively eliminate volatile organic compounds (VOCs), noxious gases, and smoke particles from indoor air, which is particularly important in sensitive environments like hospitals and laboratories. The presence of more activated carbon in air purification devices increases the carbon surface area, improving the absorption of chemical pollutants like VOCs.

In addition to its environmental applications, activated carbon is also used in healthcare to treat poisonings and overdoses. It functions like a sponge, attracting toxins to its surface and preventing their absorption into the body. Tablets or capsules of activated carbon are available over the counter in many countries to treat conditions like diarrhoea, indigestion, and flatulence. However, it is important to note that activated carbon is not effective against all types of poisons and should be used with caution.

Activated carbon has a broad range of uses due to its ability to adsorb both organic and some inorganic compounds. In industrial applications, it is used in metal finishing to purify electroplating solutions by removing organic impurities. It is also effective in removing organic compounds such as phenols, dyes, and pharmaceuticals from water. Additionally, activated carbon can be impregnated with various chemicals to enhance its adsorptive capacity for specific inorganic compounds, such as hydrogen sulfide, ammonia, formaldehyde, mercury, and radioactive iodine-131.

It can be used as a substrate to improve the adsorptive capacity for some inorganic compounds

Activated carbon is a form of carbon that is commonly used to filter contaminants from water and air. It is also used in medicine, sewage treatment, and many other applications. The 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.

Activated carbon can be used as a substrate to improve the adsorptive capacity for some inorganic compounds. For example, porous carbons containing several types of inorganic impregnates 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. Impregnated carbons are also used for the adsorption of hydrogen sulfide (H2S) and thiols.

In addition, activated carbon is useful for extracting direct oral anticoagulants (DOACs) such as dabigatran, apixaban, rivaroxaban, and edoxaban from blood plasma samples. It is also 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.

The physical and chemical properties of activated carbon affect its adsorptive capacity. For example, the adsorption capacity of activated carbon increases with the increase in adsorbate molecular weight, dynamic diameter, boiling point, and density. On the other hand, the adsorption capacity decreases with the increase in the polarity index and vapour pressure of the adsorbate.

Overall, activated carbon is a versatile material that can be used to improve the adsorptive capacity for some inorganic compounds, making it a valuable tool in various industries and applications.

It is used in metal finishing for purification and to remove organic impurities

Activated carbon, also called activated charcoal, is a form of carbon used to filter contaminants from water and air, among other uses. It has a porous structure with small, low-volume pores that increase the surface area available for adsorption or chemical reactions. Adsorption refers to the process where atoms or molecules adhere to a surface.

Activated carbon is used in metal finishing for purification and to remove organic impurities. It is the main purification technique for removing organic impurities from bright nickel plating solutions. Organic chemicals are added to plating solutions to improve deposit qualities and enhance properties like brightness, smoothness, and ductility. However, due to the passage of direct current and electrolytic reactions, organic additives can generate unwanted breakdown products. Activated carbon treatment effectively removes these impurities and restores the desired plating performance.

In addition to its use in metal finishing, activated carbon is also used in water treatment and air pollution control. It can adsorb various organic compounds, such as phenols, dyes, and pharmaceuticals, from wastewater and air streams. The high surface area and pore size of activated carbon contribute to its effectiveness in absorbing organic pollutants.

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

The efficiency of activated carbon in removing pollutants depends on various factors, such as solubility, vapour pressure, and relative humidity. It is important to select the appropriate grade and size of activated carbon based on the specific pollutant and the desired degree of purity.

It is also used to treat drug overdoses and medical conditions such as diarrhoea and indigestion

Activated carbon, also known as activated charcoal, is a medication used to treat poisonings and overdoses following oral ingestion. It is also used to treat drug overdoses and medical conditions such as diarrhoea and indigestion.

Activated carbon is a fine, odourless, black powder that is often used in emergency rooms to treat overdoses. It is created by superheating natural sources of carbon, such as wood, to produce activated charcoal. This black powder prevents toxins from being absorbed in the stomach by binding to them. The human body is unable to absorb charcoal, so the toxins that bind to the charcoal leave the body in the faeces.

Tablets or capsules of activated carbon are used in many countries as an over-the-counter drug to treat diarrhoea, indigestion, and flatulence. It may be taken by mouth or given via a nasogastric tube. It is on the World Health Organization's List of Essential Medicines.

A 2017 review of recent studies on the use of activated charcoal for diarrhoea concluded that it might prevent bacteria and drugs that cause diarrhoea from being absorbed into the body by trapping them on its porous, textured surface. The researchers also pointed out that activated charcoal had few side effects compared to common anti-diarrhoeal medications.

However, it is important to note that activated carbon is not effective against all types of poisoning. For example, it is medically ineffective if poisoning resulted from the ingestion of corrosive agents, boric acid, or petroleum products. It is also ineffective against poisonings of strong acids or bases, cyanide, iron, lithium, arsenic, methanol, ethanol, or ethylene glycol. Incorrect application, such as inhalation, can result in pulmonary aspiration, which can be fatal if not treated immediately.

Activated carbon is an environmentally friendly choice due to its capacity to eliminate pollutants without introducing by-products

Activated carbon is a versatile and environmentally friendly solution for eliminating pollutants. Its effectiveness stems from its unique properties, particularly its porous structure. This porosity, combined with attractive forces, gives activated carbon a remarkably large surface area, estimated to be greater than 1000 m^2/g. This means that just 3 grams of activated carbon can match the surface area of a football field.

The large surface area of activated carbon is essential for its ability to adsorb pollutants. Adsorption, which is distinct from absorption, occurs due to London Dispersion Forces, a type of Van der Waals force that attracts neutral molecules in liquids, air, and gases. The porous structure of activated carbon provides an extensive network of “adsorption pores,” which are gaps, cracks, and crevices where adsorption takes place. The pollutant molecules are drawn into these pores and retained, effectively removing them from the environment.

Activated carbon is particularly effective at adsorbing organic compounds, including volatile organic compounds (VOCs) such as nitrogen oxides, CO2, formaldehyde, benzene, and ethanol. VOCs are harmful gases released from various sources, including sprays, cleaning products, and building materials. By adsorbing these pollutants, activated carbon helps improve air quality and protect human health, as certain VOCs are known to be carcinogenic.

In addition to air purification, activated carbon is also widely used in water treatment. It can effectively remove organic pollutants, chlorine, and unpleasant odours from drinking water, making it safer and more palatable. Granular activated carbon (GAC) is a commonly employed method in water filtration systems. Additionally, activated carbon is used in metal finishing to purify electroplating solutions, removing organic impurities and restoring plating performance.

The versatility of activated carbon extends beyond organic compounds. It can also adsorb certain inorganic compounds when impregnated with specific substances. For example, activated carbon impregnated with iodine or silver exhibits antimicrobial and antiseptic properties, making it suitable for water purification. Furthermore, activated carbon can be used to extract oral anticoagulants from blood plasma samples, allowing for accurate analysis without affecting blood clotting factors.

Activated carbon's ability to eliminate pollutants without introducing unwanted by-products makes it an environmentally conscious choice. Its applications in air and water purification, as well as its use in various industries, contribute to its reputation as a sustainable solution. The demand for eco-friendly solutions aligns with the use of activated carbon, showcasing its potential to significantly impact human society.

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