Activated carbon is a good adsorbent, which is made of charcoal, bamboo charcoal, various shells and high-quality coal. Through physical and chemical methods, a series of processes such as crushing, screening, catalyst activation, rinsing, drying and screening are carried out. It has the dual characteristics of physical adsorption and chemical adsorption, and can selectively adsorb various substances in gas phase and liquid phase to achieve the purposes of decoloration and purification, disinfection and deodorization, decontamination and purification, etc. Its main characteristic is strong adsorption.

Second, substances easily adsorbed by activated carbon.

1, aromatic compounds with molecular structure are generally more easily adsorbed than aliphatic compounds.

2. Interfacial tension (interfacial activity) A substance that significantly reduces the surface tension of a solution is called an interfacial active substance. When saturated fatty acid or ethanol is dissolved in water, the interfacial tension of aqueous solution will increase geometrically with the increase of carbon content in additives. According to Gibbs adsorption theory, the more the interfacial tension of solution decreases, the easier it is to be adsorbed.

3. Soluble activated carbon is a hydrophobic substance, so the stronger the hydrophobicity of the adsorbed substance, the easier it is to be adsorbed. The longer the alkyl group of fatty acid is, the more hydrophobic it is, the more difficult it is to dissolve in water, and the adsorption is also enhanced. In addition, by comparing linear alcohols, fatty acids, esters and other substances with the same carbon number, it can be found that the lower the solubility, the easier it is to be adsorbed.

4. The ionic and polar nature of organic acids and amines, some of which are weakly acidic or alkaline after being dissolved in water. The adsorption capacity of this kind of weak electrolyte organic matter in non-dissociation state is greater than that in ionization state.

5. The adsorption capacity of molecular size is also related to molecular weight. The larger the molecular weight, the stronger the adsorption. However, when the adsorption amount is too large, the diffusion speed in the pores will slow down.

6. Reducing the pH value of wastewater to 2 ~ 3 before adsorption can usually improve the removal rate of organic matter. This is because when the pH value is low, the proportion of organic acids forming ions in wastewater is small, so the adsorption capacity is large.

7. Concentration With the increase of organic matter concentration in wastewater, the adsorption capacity increases exponentially, but the adsorption capacity of alkyl benzene sulfonic acid has nothing to do with the concentration.

8. Temperature of water treatment Under normal circumstances, the influence of temperature is small enough to suddenly drop.

9. The adsorption of * * * organic matter will not be affected by inorganic ions contained in natural water.