Interaction of aqueous solutions of phenol with commercial activated carbons: an adsorption and kinetic study
Interaction of aqueous solutions of phenol with commercial activated carbons: an adsorption and kinetic study
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DOI：
10.1016/s0008-6223(98)00301-7
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发表时间：
1999
期刊：
影响因子：
10.9
通讯作者：
D. M. Nevskaia;A. Santianes;V. Muñoz;A. Guerrero-Ruíz
中科院分区：
文献类型：
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作者：
D. M. Nevskaia;A. Santianes;V. Muñoz;A. Guerrero-Ruíz
用HCl、H_2F_2和HNO_3处理了三种微孔商用炭。采用N2吸附、程序升温脱附（TPD）和苯酚吸附等温线等方法，研究了不同处理方法对改性前后的比表面积和孔隙率、表面官能团和苯酚吸附行为的影响。结果表明，在活性炭的所有孔范围内都存在碳酸盐和二氧化硅杂质。这些无机杂质对苯酚吸附没有影响。当碳被氧化（通过用HNO3溶液处理）时，表面氧官能团主要位于微孔入口处。从TPD实验中发现，在原始碳的表面上有少量的羧基。在氧化碳上，TPD实验表明羧基的数量大大增加，并出现了酸酐、过氧化物和酚基。氧化碳上的苯酚的吸附显着减少，与未处理的碳相比，作为一个结果的存在下的氧表面基团。此外，已检测到从L形到阶梯状的等温线的变化，并且与原始碳相比，达到吸附平衡所需的时间更短。
Three microporous commercial carbons were treated with HCl, H2F2and HNO3. The effects of these treatments on the specific surface area and porosity, on the surface functional groups and on the adsorption behavior of phenol are studied by means of N2adsorption at 77 K, temperature-programmed desorption (TPD) and phenol adsorption isotherms, respectively. The results show that there are carbonates and silica impurities that are occluded in all pore ranges of the activated carbons. These inorganic impurities do not have an effect on the phenol adsorption. When the carbons are oxidized (by treatment with HNO3solution), the surface oxygen functional groups are principally placed on the micropores entrance. From TPD experiments some minor amounts of carboxylic groups on the surface of the original carbon have been found. On the oxidized carbons TPD experiments show a strong increase in the amount of carboxyl groups and the appearance of anhydride, peroxidic and phenolic groups. The adsorption of phenol on oxidized carbons remarkably diminished, in comparison with untreated carbons, as a consequence of the presence of oxygen surface groups. Also, a change from L-shaped to stepped isotherms has been detected and a shorter time is required to reach the adsorption equilibrium in comparison with the original carbons.