School of Space and Environment, Beihang University, Beijing, 100191, PR China.
School of Space and Environment, Beihang University, Beijing, 100191, PR China.
Chemosphere. 2018 Sep;206:285-292. doi: 10.1016/j.chemosphere.2018.04.126. Epub 2018 Apr 26.
The adsorption performance of toluene and chlorobenzene on prepared coconut shell derived carbon (CDC) is investigated and compared with commercial activated carbon (CAC) by experiment and theory calculation. Textural properties of prepared adsorbents are characterized by N adsorption, infrared spectra (FT-IR), Raman spectra and X-ray photoelectron spectra (XPS). Adsorption isotherms of toluene and chlorobenzene are obtained and fitted using structure optimizations, Grand Canonical Monte Carlo (GCMC) simulation and thermodynamic models. The results indicate that CDC shows better volatile organic compounds (VOCs) removal performance than CAC, and chlorobenzene is easily adsorbed than toluene. On the aspect of textural characteristics, CDC possesses more micropores ratio and narrower pore size distribution than CAC. Furthermore, amounts of electron-withdrawing carbonyl groups on the CAC surface reduce the electron density of adsorbents, thus weakening the interaction between VOCs and adsorbents. On the aspect of model fitting, the Yoon and Nelson (Y-N) and Dubinin-Astakhov (D-A) models can well describe the dynamic adsorption and the adsorption equilibrium of toluene and chlorobenzene on CDC respectively. It is believed that substituent groups of adsorbates, making the charge distribution deviate, lead to adsorption potentials of chlorobenzene larger than toluene. In general, both the pore structure and the surface property of adsorbents affect the VOCs adsorption behaviors on CDC.
通过实验和理论计算研究了制备的椰壳衍生碳（CDC）对甲苯和氯苯的吸附性能，并与商业活性炭（CAC）进行了比较。通过氮气吸附、红外光谱（FT-IR）、拉曼光谱和 X 射线光电子能谱（XPS）对制备的吸附剂的结构特性进行了表征。采用结构优化、巨正则蒙特卡罗（GCMC）模拟和热力学模型对甲苯和氯苯的吸附等温线进行了拟合。结果表明，CDC 对挥发性有机化合物（VOCs）的去除性能优于 CAC，且氯苯比甲苯更易被吸附。在结构特征方面，CDC 比 CAC 具有更多的微孔比例和更窄的孔径分布。此外，CAC 表面的吸电子羰基数量减少了吸附剂的电子密度，从而削弱了 VOCs 与吸附剂之间的相互作用。在模型拟合方面，Yoon 和 Nelson（Y-N）和 Dubinin-Astakhov（D-A）模型分别可以很好地描述甲苯和氯苯在 CDC 上的动态吸附和吸附平衡。可以认为，吸附质的取代基使电荷分布偏离，导致氯苯的吸附势大于甲苯。总的来说，吸附剂的孔结构和表面性质都会影响 CDC 对 VOCs 的吸附行为。
