Comparison of adsorption of Remazol Black B and Acidol Red on microporous activated carbon felt
Comparison of adsorption of Remazol Black B and Acidol Red on microporous activated carbon felt
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DOI：
10.1016/j.jcis.2009.07.057
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发表时间：
2009-11-15
影响因子：
9.9
通讯作者：
Pietrelli, L.
中科院分区：
文献类型：
--
作者：
Donnaperna, L.;Duclaux, L.;Pietrelli, L.
研究了两种阴离子染料 Remazol Black B (RB5) 和 Acidol Red 2BE-NW (AR42) 在微孔活性炭毡上的吸附情况。通过 X 射线微量分析、Boehm 滴定和 pH-PZC 测量对碳表面化学进行表征表明，表面含氧基团主要是酸性的。吸附速率取决于 pH 值，实验数据符合颗粒内扩散模型。通过DFT分析获得的孔径分布表明，平均孔径接近1 nm，这表明缓慢的颗粒内扩散过程控制着吸附。测量不同pH值的吸附等温线。 Khan 模型和 Langmuir-Freundlich 模型分别与 RB5 和 AR42 的实验数据达到最佳一致性。这些等温线模拟和吸附的 pH 依赖性表明，当 pH 值低于 4 时，吸附容量主要由非色散静电相互作用控制。吸附动力学、过程的不可逆性以及 pH 的影响表明，这种微孔毡中的吸附速率通过两个步骤进行。第一个是快速的，是染料分子与碳材料的外表面（占整个表面积的10%）直接相互作用的结果；在第二个缓慢的步骤中，吸附速率由染料分子缓慢扩散到狭窄的微孔中来控制。研究了温度对吸附等温线的影响，得到了吸附等温线的热力学参数。他们表明该过程是自发的且放热的。 (C) 2009 Elsevier Inc. 保留所有权利。
The adsorption of two anionic dyes, Remazol Black B (RB5) and Acidol Red 2BE-NW (AR42), onto a microporous activated carbon felt was investigated. The characterization of carbon Surface chemistry by X-ray microanalysis, Boehm titrations, and pH-PZC measurements indicates that the surface oxygenated groups are mainly acidic. The rate of adsorption depends on the pH and the experimental data fit the intraparticle diffusion model. The pore size distribution obtained by DFT analysis shows that the mean pore size is close to 1 nm, which indicates that a slow intraparticle diffusion process control the adsorption. The adsorption isotherms were measured for different pH values. The Khan and the Langmuir-Freundlich models lead to the best agreement with experimental data for RB5 and AR42, respectively. These isotherm Simulations and the pH dependence of adsorption show that the adsorption capacity is mainly controlled by nondispersive electrostatic interactions for pH values below 4. The adsorption kinetics, the irreversibility of the process, and the influence of the pH indicate that the rate of adsorption in this microporous felt proceeds through two steps. The first one is fast and results from direct interaction of dye molecules with the external surface of the carbon material (which account for 10% of the whole surface area); in the second, slow step, the adsorption rate is controlled by the slow diffusion of dye molecules into the narrow micropores. The influence of temperature on the adsorption isotherms was studied and the thermodynamic parameters were obtained. They show that the process is spontaneous and exothermic. (C) 2009 Elsevier Inc. All rights reserved.