Adsorption of phenol onto activated carbons having different textural and surface properties
Adsorption of phenol onto activated carbons having different textural and surface properties
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DOI：
10.1016/j.micromeso.2007.08.002
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发表时间：
2008-04-15
影响因子：
5.2
通讯作者：
Celzard, A.
中科院分区：
文献类型：
--
作者：
Fierro, V.;Torne-Fernandez, V.;Celzard, A.
研究了不同结构和表面性质的活性炭对水相中苯酚的吸附。使用六种类型的AC：三种是商业的，并且三种是从用氢氧化钠化学活化的硫酸盐木质素获得的。氢氧化钾或正磷酸。商业活性炭的表观比表面积为620 ~ 1320 m2/g，而木质素活性炭的表面积分别高达1300 m2/g和2900 m2/g，且木质素活性炭的微孔比例最高。进行了动力学研究，表明苯酚吸附数据可以正确地调整，为所有的AC测试，由一个对应于一个伪二级化学反应的方程。用Freundlich、Langmuir和Tempkin方程对吸附等温线进行了拟合，结果表明，Langmuir方程能较好地拟合实验数据。然而，Tempkin模型拟合得更好的吸附数据与活性炭来自木质素活化与碱性氢氧化物，其特征在于由最高数量的表面基团。显着高的苯酚吸附容量被发现的硫酸盐木质素与NaOH和KOH活化制备的AC：238和213毫克/克AC，分别。最后，苯酚的吸附被发现不仅取决于吸附体积，而且还取决于羰基和碱性基团的总量和酸碱基团的比例。(C)2007年爱思唯尔公司All rights reserved.
Adsorption of phenol in aqueous phase onto activated carbons (ACs) having different textural and surface properties has been considered. Six types of ACs were used: three were commercial, and three were obtained from Kraft lignin chemically activated with sodium hydroxide.. potassium hydroxide or ortho-phosphoric acid. The apparent surface areas of the commercial ACs varied from 620 to 1320 m(2)/g, while ACs made from lignin presented surface areas as high as 1300 m(2)/g and 2900 m(2)/g when prepared with H3PO4 and alkaline hydroxides, respectively; moreover, the highest proportion of microporosity was found for ACs derived from lignin. A kinetic study was carried out, showing that the phenol adsorption data may be correctly adjusted, for all the ACs tested, by an equation corresponding to a pseudo second-order chemical reaction. Freundlich, Langmuir and Tempkin equations were tested for modelling the adsorption isotherms at equilibrium, and it was concluded that Langmuir model fitted adequately the experimental data. However, Tempkin model fitted even better the adsorption data obtained with ACs derived from lignin activated with alkaline hydroxides, which are characterized by the highest number of surface groups. Remarkably high phenol adsorption capacities were found for the ACs prepared by activation of Kraft lignin with NaOH and KOH: 238 and 213 mg/g of AC, respectively. Finally, the adsorption of phenol was found to depend not only on the micropore volume, but also on the total amount of carbonyl and basic groups and on the ratio of acid to basic groups. (C) 2007 Elsevier Inc. All rights reserved.