Many industrial wastewaters in industrial wastewater treatment contain difficult-to-degrade organics, which are difficult or impossible to remove by conventional biological methods, such as ABS and certain heterocyclic compounds. These substances can be removed by adsorption.
According to the different adsorption capacity of the solid surface, adsorption can be divided into two types: physical adsorption and chemical adsorption.
1. Physical adsorption
The adsorption produced by intermolecular forces between the adsorbent and the adsorbate is called physical adsorption. Physical adsorption is a common adsorption phenomenon. Since the adsorption is caused by molecular forces, the heat of adsorption is small, generally within 41.9kj/mol.
2. Chemical adsorption
Chemical adsorption is a chemical interaction between adsorbent and adsorbate, which is caused by chemical bonding. Chemical adsorption is generally carried out at a higher temperature, and the heat of adsorption is relatively large, which is equivalent to the heat of chemical reaction, generally 83.7-418.7kj/mol.