Why are coal-based columnar activated carbon used more and more?

There are many kinds of adhesives.

Why are coal-based columnar activated carbon used more and more?
There are many kinds of adhesives. At present, the main binders commonly used in the production of coal-based columnar activated carbon are coal tar, sodium lignosulfonate, pulp waste liquid and starch solution. However, considering the source of the binder, coal tar is generally selected as the binder. In terms of product quality ratio, coal tar is a more suitable binder for the production of coal-based columnar activated carbon. However, using coal tar as a binder requires a pitch content of more than 50%, a water content of less than 5%, and a good viscosity. The water is not easy to be too high, because too much water affects the strength of the carbon ribbon, so what is the requirement of the coal-based columnar activated carbon for the binder?
1. High carbon content, high coking rate during pyrolysis, which can form a part of activated carbon itself and play the role of skeleton.
2. It has certain rheological properties, good permeability to the matrix particles, and plasticity after being mixed with the matrix, which is conducive to the processing of the matrix raw materials into granular materials.
3. Adhesive. In this process, the matrix can be combined into a whole particle, and it has high mechanical strength.
4. It is conducive to the formation of the initial pores of activated carbon particles, has no adverse effect on the processing process, and plays a pore-making effect. The important thing above is penetration and adhesion.
With the continuous development of the economy and the continuous progress of the society, the population living in cities has also grown substantially, and water shortages have become a headache for many cities. Urban domestic sewage is the product of urban development. With the acceleration of the process of urbanization and industrialization, output has continued to rise. The problem of water pollution seriously affects the sustainable development of urban society and economy and the health of the people. Some organic matter in wastewater is difficult to be oxidized and decomposed by microorganisms or general oxidation methods, such as phenol, benzene, petroleum, detergent and other synthetic dyes and other compounds, and synthetic organic matter is difficult to meet the discharge requirements. The water after biochemical treatment also seriously affects the reuse of wastewater. , So in-depth processing is required. However, my country's fresh water resources are scarce, and the reuse of industrial wastewater and urban sewage and the development of renewable water resources are imminent.
Because columnar activated carbon can effectively deodorize, decolorize, and effectively remove various toxic substances in water quality, more and more cities and factories have begun to use columnar activated carbon for sewage treatment. What are the characteristics of columnar activated carbon for sewage treatment?
Columnar activated carbon has the three characteristics of large adsorption capacity, fast adsorption speed and good mechanical strength. The adsorption capacity of activated carbon is mainly related to the specific surface area of ​​activated carbon. It has a large specific surface area and a large number of micropores. The adsorption rate is mainly related to the particle size and pore distribution of activated carbon. Activated carbon used in wastewater treatment needs developed transition pores, which is conducive to the diffusion of adsorbate into the micropores. The lower the strength of the activated carbon, the faster the adsorption speed, but the head loss will increase, generally in the range of 8-30 mesh, but the mechanical wear resistance of the activated carbon will directly affect the service life of the columnar activated carbon.