Activated carbon is a specially treated carbon.Activated carbon is prepared by pyrolysis and activation of carbon-containing raw materials such as wood, coal, and petroleum coke. It has a developed pore structure, a large specific surface area, and rich surface chemical groups, and has a strong specific adsorption capacity. Collective name for carbon materials.
Characteristics of activated carbon
Activated carbon adsorption method is the use of porous activated carbon to remove one or more substances on the surface of activated carbon. The objects to be removed include soluble organic substances, synthetic detergents, microorganisms, viruses and a certain amount of heavy metals. And can decolorize, deodorize, and purify the air.
In addition to physical adsorption, activated carbon also has chemical adsorption. The adsorption of activated carbon depends on both the pore structure and the chemical composition.
Activated carbon not only contains carbon, but also contains a small amount of chemically bound, functional group-operating oxygen and hydrogen, such as carbonyl, carboxyl, phenols, lactones, quinones, and ethers. Some of the oxides and complexes on the surface are derived from raw materials, and some are generated by the action of air or water vapor during and after activation. Sometimes surface sulfides and chlorides are also formed. During activation, the minerals contained in the raw materials are concentrated in the activated carbon and become ash. The main components of ash are salts of alkali metals and alkaline earth metals, such as carbonates and phosphates.
- Granularity: A set of standard sieving methods are used to find the weight of activated carbon remaining in and passing through each sieve, which represents the particle size distribution.
- Mesodensity or bulk density: It should be the volume of activated carbon per unit volume of pore volume and interparticle void volume.
- Bulk density and particle density: The weight per unit volume of activated carbon should be the pore volume and not the inter-particle void volume.
- Strength: the crush resistance of activated carbon.
- Abrasion resistance: the resistance to abrasion or friction.
These mechanical properties directly affect the application of activated carbon, such as: density affects the size of the container; powdery carbon thickness affects filtration; granular carbon particle size distribution affects fluid resistance and pressure drop; crushability affects the life of activated carbon and waste carbon regeneration.
Types of activated carbon
Due to the different sources of raw materials, manufacturing methods, appearance shapes, and applications, there are many types of activated carbon. So far, there are no accurate statistical materials, and there are about thousands of varieties.
Application fields of activated carbon
By raw material source
Divided by appearance shape
- Powdered activated carbon
- Granular activated carbon
- Unshaped granular activated carbon
- Columnar activated carbon
- Spherical activated carbon
- Other shapes of activated carbon
Uses of activated carbon
Urban sewage treatment
Some organic substances in the wastewater are difficult to be oxidized and decomposed by microorganisms or general oxidation methods, such as phenol, benzene, petroleum and its products, pesticides, detergents, synthetic dyes, amine compounds, and many artificial organic compounds, which are biochemically treated It is difficult to meet the discharge standards in water bodies with higher discharge requirements later, and it also seriously affects the reuse of wastewater, so it needs advanced treatment.
Application in advanced treatment of drinking water
Activated carbon adsorption is built on the basis of conventional water treatment. Generally, it is set after sand filtration. It can also be composed of sand filter and double-layer filter or activated carbon instead of sand.
In the process of deep drinking water treatment using activated carbon adsorption, it was found that a large number of microorganisms grew on the activated carbon filter material, which improved the quality of the effluent water and prolonged the regeneration. Therefore, a cost-effective biological activated carbon for removing micro-pollutants in water was developed The process is as follows: raw water-(add coagulant)-clarification-filtration (add ozone), then activated carbon adsorption, and finally water.
Activated carbon for home use
- Air purification: Place activated carbon in the room to effectively absorb formaldehyde, xylene, etc. contained in the air
- Harmful substances (such as formaldehyde)
- Deodorization of furniture: Activated carbon can be applied to newly purchased furniture in cabinets \ drawers \ refrigerators, or in shoes to deodorize.
- Car deodorization: New cars generally contain a lot of harmful substances \ unpleasant pungent odor, which can be effectively removed with activated carbon.
- Air purification
- Sewage treatment plant exhaust adsorption
- Drink water treatment
- Power plant water pretreatment
- Pre-treatment of wastewater recycling
- Biological wastewater treatment
- Toxic wastewater treatment
- Petrochemical alkali-free desulfurization alcohol
- Solvent recovery
- Chemical catalyst carrier
- Gold extraction
- Purification of chemical products storage exhaust
- Sugar, alcohol, MSG medicine, food refining, decoloring
- Ethylene desalinated filler
- Car exhaust purification
- PTA oxidation device purification gas
- Impurity removal of printing ink
- Activated carbon for methane production
- Extraction of electrolytic nickel
- Extraction of amino acids