活性炭表面改性和苯吸附性能的研究

Research on surface modification and benzene adsorption performance of activated carbon

为了提高活性炭的吸附性能,用N2和NH3对四种不同活性炭进行表面改性。对改性前后的活性炭分别进行了苯吸附实验、碘值和亚甲基兰值表征以及贝姆滴定实验后,结果发现:表面还原改性在一定程度上促进了活性炭的孔结构发育,可以提高活性炭的吸附性能,增加了活性炭表面的碱性官能团的含量;四种活性炭中的羧基含量都比较高,改性后羧基含量大幅下降;表面改性对煤质活性炭的苯吸附值变化不大,但对木质活性炭的防护性能提高明显,NH3改性比N2改性更能提高活性炭对苯的吸附性能。

In order to improve the adsorption performance of activated carbon, the surface modification of four dif-ferent kinds of activated carbon were conducted with the aid of NH3 and N2 .The experiments of benzene adsorp-tion, iodine number, methylene blue value representation and Boehm titration were performed on original and modi-fied activated carbons.The results showed that：surface modification can promote the pore structure development to a certain extent, and improve the adsorption performance of activated carbon.It increased the amount of basic func-tional groups on the surface of activated carbon.The carboxyl contents of four kinds of activated carbon were all higher, however, the carboxyl content dropped significantly after modification.The improvement of benzene adsorp-tion value by surface modification was more obvious for wood-based activated carbon than coal-based activated car-bon, and the improvement was more obvious for NH3 modification than N2 modification.