Adsorption of aromatic compounds by carbonaceous adsorbents: a comparative study on granular activated carbon, activated carbon fiber, and carbon nanotubes.
Adsorption of aromatic compounds by carbonaceous adsorbents: a comparative study on granular activated carbon, activated carbon fiber, and carbon nanotubes.
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DOI：
10.1021/es100874y
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发表时间：
2010-07
影响因子：
11.4
通讯作者：
Shujuan Zhang;Ting Shao;H. Kose;T. Karanfil
中科院分区：
文献类型：
--
作者：
Shujuan Zhang;Ting Shao;H. Kose;T. Karanfil
研究了4种不同结构特征但表面极性相似的碳质吸附剂[颗粒活性碳(HD4000)、活性碳纤维(ACF10)、两个单壁碳纳米管(SWNT、SWNT-HT)和多壁碳纳米管(MWNT)]对3种芳香族有机物(AOCs)的吸附性能。等温线实验结果表明，分子筛分和微孔效应在炭质多孔吸附剂吸附AOCs过程中具有重要作用。在没有分子筛效应的情况下，AOCs的吸附容量与吸附剂的比表面积呈线性关系，与吸附剂的类型无关。吸附剂的孔容占有率顺序为ACF10>；HD4000>；SWNT>；MWNT，表明吸附中心的有效性与吸附剂的孔径分布有关。具有较大微孔体积的ACF10和HD4000对低分子质量AOCs的吸附亲和力高于具有较高中孔和大孔体积的SWNT和MWNT。由于其较大的孔径，单壁碳纳米管和多壁碳纳米管有望更有效地吸附大尺寸分子。从单壁碳纳米管中去除表面含氧官能团增强了对AOCs的吸附。
Adsorption of three aromatic organic compounds (AOCs) by four types of carbonaceous adsorbents [a granular activated carbon (HD4000), an activated carbon fiber (ACF10), two single-walled carbon nanotubes (SWNT, SWNT-HT), and a multiwalled carbon nanotube (MWNT)] with different structural characteristics but similar surface polarities was examined in aqueous solutions. Isotherm results demonstrated the importance of molecular sieving and micropore effects in the adsorption of AOCs by carbonaceous porous adsorbents. In the absence of the molecular sieving effect, a linear relationship was found between the adsorption capacities of AOCs and the surface areas of adsorbents, independent of the type of adsorbent. On the other hand, the pore volume occupancies of the adsorbents followed the order of ACF10 > HD4000 > SWNT > MWNT, indicating that the availability of adsorption site was related to the pore size distributions of the adsorbents. ACF10 and HD4000 with higher microporous volumes exhibited higher adsorption affinities to low molecular weight AOCs than SWNT and MWNT with higher mesopore and macropore volumes. Due to their larger pore sizes, SWNTs and MWNTs are expected to be more efficient in adsorption of large size molecules. Removal of surface oxygen-containing functional groups from the SWNT enhanced adsorption of AOCs.