Enzyme Bioconversion Unit (UR13ES74), National School of Engineering, P.O. Box 1173, 3038, Sfax University, Tunisia.
Laboratoire Transformations Intégrées de la Matière Renouvelable (UTC/ESCOM, EA 4297 TIMR), Université de Technologie de Compiègne, Centre de Recherche de Royallieu, CS 60319, 60203 Compiègne Cedex, France.
Int J Biol Macromol. 2017 Dec;105(Pt 1):56-65. doi: 10.1016/j.ijbiomac.2017.06.106. Epub 2017 Jun 29.
This work aimed at investigating the potential of almond gum as low cost adsorbent for the removal of the cationic dye; malachite green from aqueous solutions. Almond gum was first analyzed by scanning electron microscopy (SEM) and Fourier transforms infrared spectroscopy (FTIR), and then the adsorption behavior was studied in batch system. The effects of the adsorption parameters (adsorbent dose, pH, contact time, particle size, initial dye concentration, temperature and agitation) on the dye removal have been studied. Adsorption equilibrium and isotherms were evaluated depending on temperature using the isotherms of Freundlich, Langmuir, and Tempkin. The obtained result showed that both Langmuir and Freundlich models were adapted to study the dye sorption. The maximum adsorption capacities were equal to 172.41mg/g, 181.81mg/g, and 196.07mg/g at 303.16K, 313.16K, and 323.16K, respectively. The kinetics of sorption were following the pseudo-second order model. The thermodynamic changes in enthalpy (ΔH), entropy (ΔS), and free energy (ΔG) indicated that the adsorption of malachite green at the surface of almond gum is endothermic and occurs spontaneously. Desorption experiments were conducted to regenerate almond gum, showing great desorption capacity when using HCl at pH 2.
本研究旨在探索杏仁胶作为一种低成本吸附剂，用于从水溶液中去除阳离子染料孔雀石绿。首先通过扫描电子显微镜（SEM）和傅里叶变换红外光谱（FTIR）对杏仁胶进行了分析，然后在批处理系统中研究了吸附行为。研究了吸附参数（吸附剂剂量、pH、接触时间、粒径、初始染料浓度、温度和搅拌）对染料去除的影响。根据温度评估了吸附平衡和等温线，使用 Freundlich、Langmuir 和 Tempkin 等温线。结果表明，Langmuir 和 Freundlich 模型都适用于研究染料吸附。在 303.16K、313.16K 和 323.16K 下，最大吸附容量分别为 172.41mg/g、181.81mg/g 和 196.07mg/g。吸附动力学符合拟二级动力学模型。吸附焓（ΔH）、熵（ΔS）和自由能（ΔG）的热力学变化表明，在杏仁胶表面吸附孔雀石绿是吸热的，并且是自发进行的。进行了脱附实验以再生杏仁胶，当使用 pH 2 的 HCl 时显示出很大的脱附容量。
