吸附现象是发生在两个不同的相界面的现象，吸附过程就是在界面上的扩散过程，是发生在固体表面的吸附，这是由于固体表面存在着剩余的吸引而引起的。吸附可分为物理吸附和化学吸附；物理吸附亦称范德华吸附，是由于吸附剂与吸附质分子之间的静电力或范德华引力导致物理吸附引起的，当固体和气体之间的分子引力大于气体分子之间的引力时，即使气体的压力低于与操作温度相对应和饱和蒸气压，气体分子也会冷凝在固体表面上，物理吸附是一种吸热过程。
The adsorption phenomenon occurs at two different phase interfaces. The adsorption process is the diffusion process at the interface, which occurs on the solid surface, which is caused by the residual attraction on the solid surface. Adsorption can be divided into physical adsorption and chemical adsorption; physical adsorption, also known as van der Waals adsorption, is caused by the electrostatic force or van der Waals gravitation between adsorbent and adsorbate molecules. When the molecular gravity between solid and gas is greater than that between gas molecules, even if the gas pressure is lower than the corresponding operating temperature and saturated vapor pressure, the gas molecules will also Physical adsorption is an endothermic process.
化学吸附亦称活性吸附，是由于吸附剂表面与吸附质分子间的化学反应力导致化学吸附，它涉及分子中化学键的破坏和重新结合，因此，化学吸附过程的吸附热较物理吸附过程大。
Chemical adsorption, also known as active adsorption, is caused by the chemical reaction force between the adsorbent surface and the adsorbate molecules, which involves the destruction and re combination of chemical bonds in molecules. Therefore, the adsorption heat of chemical adsorption process is larger than that of physical adsorption process.
在吸附过程中，物理吸附和化学吸附之间没有严格的界限，同一物质在较低温度下往往是化学吸附。活性炭纤维吸附以物理吸附为主，但由于表面活性剂的存在，也有一定的化学吸附作用。
In the process of adsorption, there is no strict boundary between physical adsorption and chemical adsorption, and the same substance is often chemisorption at lower temperature. The adsorption of activated carbon fiber is mainly physical adsorption, but due to the existence of surfactant, it also has certain chemical adsorption.
3.1活性炭对VOCs废气处理的特点
3.1 characteristics of VOCs waste gas treatment by activated carbon
（1）对于芳香族化合物的吸附优于对非芳香族化合物的吸附。
(1) The adsorption of aromatic compounds is better than that of non aromatic compounds.
（2）对带有支键的烃类物理优于对直链烃类物质的吸附。
(2) The physical adsorption of branched hydrocarbons is better than that of straight chain hydrocarbons.
（3）对有机物中含有无机基团物质的吸附总是低于不含无机基团物质的吸附。
(3) The adsorption of inorganic group in organic matter is always lower than that of non inorganic group.
（4）对分子量大和沸点高的化合物的吸附总是高于分子量小和沸点低的化合物的吸附。
(4) The adsorption of compounds with high molecular weight and high boiling point is always higher than that of compounds with small molecular weight and low boiling point.
（5）吸附质浓度越高，吸附量也越高。
(5) The higher the concentration, the higher the adsorption amount.
（6）吸附剂内表面积越大，吸附量越高。
(6) The larger the internal surface area of adsorbent, the higher the adsorption capacity.
