吸附現象是發生在兩個不同的相界面的現象，吸附過程就是在界面上的擴散過程，是發生在固體表面的吸附，這是由于固體表面存在著剩余的吸引而引起的。吸附可分為物理吸附和化學吸附；物理吸附亦稱范德華吸附，是由于吸附劑與吸附質分子之間的靜電力或范德華引力導致物理吸附引起的，當固體和氣體之間的分子引力大于氣體分子之間的引力時，即使氣體的壓力低于與操作溫度相對應和飽和蒸氣壓，氣體分子也會冷凝在固體表面上，物理吸附是一種吸熱過程。
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.
化學吸附亦稱活性吸附，是由于吸附劑表面與吸附質分子間的化學反應力導致化學吸附，它涉及分子中化學鍵的破壞和重新結合，因此，化學吸附過程的吸附熱較物理吸附過程大。
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.
在吸附過程中，物理吸附和化學吸附之間沒有嚴格的界限，同一物質在較低溫度下往往是化學吸附。活性炭纖維吸附以物理吸附為主，但由于表面活性劑的存在，也有一定的化學吸附作用。
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活性炭對VOCs廢氣處理的特點
3.1 characteristics of VOCs waste gas treatment by activated carbon
（1）對于芳香族化合物的吸附優于對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）對帶有支鍵的烴類物理優于對直鏈烴類物質的吸附。
(2) The physical adsorption of branched hydrocarbons is better than that of straight chain hydrocarbons.
（3）對有機物中含有無機基團物質的吸附總是低于不含無機基團物質的吸附。
(3) The adsorption of inorganic group in organic matter is always lower than that of non inorganic group.
（4）對分子量大和沸點高的化合物的吸附總是高于分子量小和沸點低的化合物的吸附。
(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）吸附質濃度越高，吸附量也越高。
(5) The higher the concentration, the higher the adsorption amount.
（6）吸附劑內表面積越大，吸附量越高。
(6) The larger the internal surface area of adsorbent, the higher the adsorption capacity.
