① Properties of activated carbon adsorbent
The larger the surface area, the stronger the adsorption capacity; activated carbon is a non-polar molecule, which is easy to adsorb non-polar or very low polar adsorbate; the size of activated carbon adsorbent particles, the structure and distribution of pores, and the surface chemical properties, etc. It also has a great influence on adsorption.
②The nature of the adsorbate
Depends on its solubility, surface free energy, polarity, size and unsaturation of adsorbate molecules, concentration of adsorbate, etc.
③PH value of waste water
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, thus affecting the adsorption effect.
④ Coexisting substances
When a variety of adsorbates coexist, the adsorption capacity of activated carbon for a certain adsorbate is worse than that of only this kind of adsorbate.
⑤ temperature
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 can be fully utilized. Activated carbon chemical properties, activated carbon adsorption in addition to physical adsorption, as well as 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 oxygen and hydrogen that are chemically bonded and functional, such as carbonyl, carboxyl, phenols, lactones, quinones, and ethers. Some of the oxides and complexes contained on these surfaces come from derivatives of raw materials, and some are generated by the action of air or water vapor during or after activation. Sometimes surface sulfides and chlorides are also generated. During the activation, the minerals contained in the raw materials are concentrated in the activated carbon to become ash. The main components of the ash are salts of alkali metals and alkaline earth metals, such as carbonates and phosphates.
