Activated carbon purification adsorber (Dongguan Meijun Automation Equipment Co., Ltd.)

Activated carbon is a very fine carbon particle with a large surface area, and because of the large surface area of ​​carbon particles, the study of the surface area of ​​activated carbon is very important.

 
Activated carbon is a hydrophobic adsorbent made of carbon-based materials, carbonized and activated at high temperature. It is a very fine carbon particle with a large surface area.
Activated carbon particles also contain a large number of smaller pores - capillaries, which have strong adsorption capacity, micropores, and a huge specific surface area, so they can be fully contacted with gases (impurities), and when these gases (impurities) touch When the capillary is adsorbed, it can purify, effectively remove color and odor, and can remove most organic pollutants and some inorganic substances in the secondary effluent, including some toxic heavy metals.
The storage box made of activated carbon and other auxiliary facilities enable activated carbon to absorb more bad gases in a short time, purify more impurities and smells in polluted gases, and achieve the purpose of exhaust gas treatment.
 
The factors that affect the adsorption of activated carbon are: the characteristics of activated carbon; the characteristics and concentration of the adsorbate; the PH value of the wastewater; the content of suspended solids and other characteristics; Activated carbon adsorption is the most important and effective treatment technology in the advanced treatment of urban sewage, and has been widely used.
Activated carbon can effectively adsorb chlorinated hydrocarbons, organophosphorus and carbamate pesticides, as well as phenyl ether, n-nitrochlorobenzene, naphthalene, ethylene, xylenol, benzene powder, DDT, aldrin, alkyl Benzenesulfonic acid and many esters and aromatic compounds. The secondary effluent also contains organics that are not adsorbed by activated carbon, such as intermediate degradation substances of proteins, which are more difficult to be adsorbed by activated carbon than the original organic matter, and the removal capacity of activated carbon for THMS is low, only reaching 23-60%. The activated carbon adsorption method is used in combination with other treatment methods, and there are ozone-activated carbon method, coagulation-adsorption activated carbon method, Habberer process, activated carbon-diatomite method, etc., which significantly prolong the adsorption period of activated carbon, reduce the dosage, and improve the treatment effect and scope. substantial improvement.
 
 
Adsorption is the slow-acting process of one substance attaching to the surface of another. Adsorption is an interfacial phenomenon
Activated carbon adsorption method, which is related to the change of surface tension and surface energy. There are two driving abilities that cause adsorption, one is the repulsion of solvent water to hydrophobic substances, and the other is the affinity attraction of solids to solutes.

Most of the adsorption in wastewater treatment is the result of the combined effect of these two forces. The specific surface area and pore structure of activated carbon directly affect its adsorption capacity. When selecting activated carbon, it should be determined through experiments according to the quality of wastewater. For printing and dyeing wastewater, carbon species with developed transition pores should be selected. In addition, the ash content also has an effect. The smaller the ash content, the better the adsorption performance; the closer the size of the adsorbate molecule is to the carbon pore diameter, the easier it is to be adsorbed; the adsorbate concentration also affects the adsorption capacity of activated carbon. Within a certain concentration range, the adsorption capacity increases with the increase of the adsorbate concentration. In addition, water temperature and pH also play a role. The adsorption capacity decreased with the increase of water temperature and increased with the decrease of pH value. Therefore, low water temperature and low pH value are beneficial to the adsorption of activated carbon.

Adsorption of activated carbon
Adsorption refers to the effect of liquid or gas adhesion and concentration on the solid surface, which can occur in general activated carbon. Adsorption is different from absorption. Absorption refers to allowing liquid or gas to enter the internal atomic structure of a solid, but activated carbon does not have such ability. Its adsorption is only a surface phenomenon, so it only occurs on its surface.
The formation of adsorption mainly comes from the London dispersion force, which is also another form of Van der Waals force. This force is common between molecules that do not have a permanent dipole moment, and it is a natural attraction. This force occurs naturally as long as the molecules are close enough. Any action that can use this force to attract substances is called physical adsorption. This force is independent of temperature, so it is not affected by temperature.
The London dispersion force must occur after the carbon surface and the adsorbed molecules have reached an acting distance, and the magnitude of this force involves the degree to which all relevant atoms in the adsorbed molecules are in close contact with the carbon atoms on the activated carbon surface. If the degree of contact is higher, the force is larger, and the adsorption capacity of the activated carbon for the molecule is also stronger.
 
① Properties of activated carbon adsorbents
The larger the specific surface area of ​​activated carbon, the stronger the adsorption capacity; activated carbon is a non-polar molecule, which is easy to adsorb non-polar or very low-polar adsorbates; the size of activated carbon adsorbent particles, the structure and distribution of pores and the surface chemical The properties and so on also have a great influence on the adsorption.
②Properties of Adsorbates
Depends on its solubility, surface free energy, polarity, size and unsaturation of adsorbate molecules, concentration of adsorbate, etc.
③ Wastewater PH value
Activated carbon generally has a higher adsorption rate in acidic solutions than in alkaline solutions.
The pH value will affect the state and solubility of the adsorbate in water, thereby affecting the adsorption effect.
④Coexisting substances
When multiple adsorbates coexist, the adsorption capacity of activated carbon for a certain kind of adsorbate is worse than that when only this kind of adsorbate is contained
⑤Temperature
Temperature has little effect on the adsorption of activated carbon
⑥Contact time
It should be ensured that the activated carbon and the adsorbate have a certain contact time, so that the adsorption is close to equilibrium and the adsorption capacity is fully utilized.
Activated carbon chemistry

The adsorption of activated carbon is not only physical adsorption, but also chemical adsorption. The adsorption properties of activated carbon depend on both the pore structure and the chemical composition.

Company address: No. 33, Xinxing Road, Xinlian Community, Humen Town, Dongguan City

Company Tel: 0769-82261696    13215392671 (WeChat) Manager Zhong

Company website: http://www.dgmagin.com