State Key Laboratory of Pollution Control and Resource Rescue, Tongji University, Shanghai 200092, China.
J Colloid Interface Sci. 2011 May 15;357(2):474-9. doi: 10.1016/j.jcis.2011.01.017.
In this study, granular activated carbon (GAC) coated with cetyltrimethyl ammonium bromide (CTAB) (GAC-CTAB) was synthesized to remove perchlorate from water via adsorption. Laboratory-scale batch experiments were performed to study the factors affecting the perchlorate adsorption by GAC-CTAB, including the CTAB content and solution pH, and explore the mechanisms behind the adsorption phenomenon. The novel GAC-CTAB material was characterized by scanning electron microscopy (SEM), zeta potential measurement and Brunauer-Emmett-Teller (BET) analysis. The characterization tests showed that CTAB was deposited on the GAC surface, pH(pzc) of the material was between 2.0 and 3.0, and the BET specific surface area was reduced from 925 to 729 m(2)/g with the increasing CTAB content from 0 to 0.034 mmol CTAB/g GAC. The adsorption process was better described by a pseudo-second-order kinetics model and the Freundlich adsorption model. The CTAB content and solution pH significantly influenced the kinetics and chemical equilibrium of the adsorption. When the CTAB content was increased from 0.0.023 to 0.135 mmol CTAB/g GAC, the K in the Freundlich adsorption isotherm increased from 0.071 to 0.19 mmol/g. The optimal adsorption typically occurred at pH 2-3, close to the pH(pzc) of the solution. Finally, the mechanisms for the adsorption of perchlorate on GAC-CTAB were associated with surface complexation, electrostatic interaction and ion exchange.
在这项研究中，合成了用十六烷基三甲基溴化铵（CTAB）包覆的颗粒状活性炭（GAC-CTAB），通过吸附去除水中的高氯酸盐。进行了实验室规模的批量实验，以研究影响 GAC-CTAB 吸附高氯酸盐的因素，包括 CTAB 含量和溶液 pH，并探讨吸附现象背后的机制。通过扫描电子显微镜（SEM）、动电电位测量和 Brunauer-Emmett-Teller（BET）分析对新型 GAC-CTAB 材料进行了表征。表征测试表明，CTAB 沉积在 GAC 表面上，材料的 pH(pzc)在 2.0 到 3.0 之间，随着 CTAB 含量从 0 增加到 0.034mmol CTAB/g GAC，BET 比表面积从 925 减少到 729m(2)/g。吸附过程更符合准二级动力学模型和 Freundlich 吸附模型。CTAB 含量和溶液 pH 显著影响吸附的动力学和化学平衡。当 CTAB 含量从 0.0.023 增加到 0.135mmol CTAB/g GAC 时，Freundlich 吸附等温线中的 K 从 0.071 增加到 0.19mmol/g。最佳吸附通常发生在 pH 2-3，接近溶液的 pH(pzc)。最后，GAC-CTAB 吸附高氯酸盐的机制与表面络合、静电相互作用和离子交换有关。
