Purification of shell activated carbon in industrial wastewater treatment

Shell activated carbon is widely used in deep purification of drinking water, industrial water and wastewater, industrial water purification and gas phase adsorption, such as power plants, petrochemicals, oil refineries, food and beverage, sugar making, medicine, electronics, fish farming, shipping The water purification treatment of the industry can effectively adsorb free chlorine, phenol, sulfur and other organic pollutants in the water, especially the precursor substances of the mutant (THM), to purify and remove impurities and odor. It can also be used for industrial exhaust gas purification, gas desulfurization, petroleum catalytic reforming, gas separation, pressure swing adsorption, air drying, food preservation, gas mask, solvent carrier, industrial solvent filtration, decolorization and purification. Separation, purification, purification of various gases; recovery of organic solvents; decolorization, deodorization, refining of sugar, monosodium glutamate, medicine, alcohol, beverages; refining of precious metals; catalysts and catalyst carriers in the chemical industry. The product has more functions of decolorization, purification, impurity removal, deodorization, odor removal, carrier, purification and recovery.

Micropores are the smallest pores in activated carbon. Its effective radius is quite small and is of the same order of magnitude as the molecules being adsorbed. Therefore, the adsorption energy in the micropores, that is, the adsorption potential in the micropores, is much higher than the corresponding adsorption potential generated on the surfaces of the transition pores, the macropores, and the nonporous adsorbent having the same chemical properties. Then, how is such a tiny pore formed in the production process of activated carbon? It is well known that in the preparation process of activated carbon, the raw material undergoes a series of processes such as carbonization and activation, and finally the activated carbon is obtained. Then in this series of changes, especially in the carbonization process, most of the non-carbon elements oxygen, hydrogen and nitrogen are decomposed into gas at high temperature, and the free carbon atoms of non-carbon elements are formed. Graphite crystallites, the lamellar lattice of these crystallites have few regular orientations. Moreover, the crystallites are arranged in an irregular manner and are highly dispersed. A variety of differently shaped voids are left between the crystallites, and these voids are filled and sealed by tar-like substances, so-called amorphous carbon. During the activation process, due to the high temperature and the presence of the activating gas, these substances are washed away by steam, leaving the gaps as what we call micropores, which are the original micropores. If we further activate, the pore volume of the micropores is further increased, which is called reaming.

Physical and chemical properties of activated carbon

Activated carbon is a black powdery or granular amorphous carbon which is a porous carbon having a low bulk density and a large specific surface area. Activated carbon has a strong "physical adsorption" and "chemical adsorption" effect, which can adsorb some organic compounds to achieve the removal effect. With this principle, we can quickly and effectively remove harmful substances in the aquarium water quality. , odor, pigments, etc., to achieve direct and rapid improvement in water quality.

The main element contained in activated carbon is carbon, the content of which is 90%~95%; followed by the organic component, wherein the oxygen content is 4%~5%, the hydrogen content is 1%~2%, and the activated carbon produced by zinc chloride method It also contains a small amount of chlorine; the inorganic component of activated carbon is ash, and its content and composition are greatly affected by the raw materials, activation methods and post-treatment conditions.

The ash content of activated carbon in wood-zinc chloride method is below 4%, the ash content of activated carbon in wood-burning method is below 8%, and the ash content of coal-based activated carbon (formed granular carbon) is usually higher than 20%, using phenolic resin and polypyramid. The ash content of activated carbon prepared by dichloroethylene can reach 0.1% or less. The composition of ash is relatively complex, mainly oxides and salts of silicon, iron, calcium, magnesium, aluminum, sodium and potassium.

When hydrogen is activated, hydrogen and oxygen are continuously reduced, but at the same time, some extraneous oxygen is adsorbed. Some of them are chemisorbed to form surface oxides. When desorbed, they are released in the form of carbon dioxide or carbon monoxide. The effect of the adsorption of acid or alkali on activated carbon is great.

The most common organic functional groups in activated carbon are gum base, phenolic base, oxime type carboxyl group, and ether, peroxide, dihaloic acid, fluorescein-type vinegar and the like are also found.

The field of application of activated carbon is expanding and the number of applications is increasing. The safety issues in the application of activated carbon should not be taken lightly. The following problems should be noted during use:

It is impossible to clean the debris that is clogged in the pores of the activated carbon by simple cleaning. Therefore, it is important to replace the activated carbon regularly to prevent the activated carbon from losing its effect due to "adsorption saturation." And the timing of replacement is best not to wait for it to fail after replacement, in order to ensure that activated carbon can continuously remove harmful substances in the aquarium water quality.

Wash and remove dust before use, otherwise these black dust may temporarily affect the cleanliness of the water. However, it is not recommended to rinse directly with fresh tap water, because the porous pores of activated carbon once adsorbed a large amount of chlorine and bleaching powder in tap water, which will cause damage to water when it is subsequently placed in a filter.

The efficiency of the treatment of activated carbon with water is related to the amount of treatment, and it is usually "the effect of using water to treat water is relatively good."

When using a medicament for treating fish diseases, the activated carbon should be temporarily taken out and suspended for use, so as to prevent the drug from being adsorbed by the activated carbon and reducing the therapeutic effect.

After the quantitative activated carbon is used, the change of water quality should be observed frequently in the initial stage of use, and the observation results should be paid attention to as the basis for judging how long it takes for the activated carbon to be replaced.

Hardwood Core Film Faced Plywood

Hardwood Core Film Faced Plywood,Hardwood Core Plywood,Full Hardwood Film Faced Plywood

Linyi Chanta Plywood Co., Ltd. , http://www.lyplywood.com