Moussout Hamou, Ahlafi Hammou, Aazza Mustapha, Chfaira Rachid, Mounir Chadia
Laboratory of Chemistry and Biology Applied to the Environment, Faculty of Sciences, Moulay Ismaïl University, BP 11201-Zitoune, Meknes, 50070, Morocco.
Heliyon. 2020 Mar 24;6(3):e03634. doi: 10.1016/j.heliyon.2020.e03634. eCollection 2020 Mar.
A raw Moroccan clay locally named "Ghassoul" (Gh) was characterized using several techniques such as Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Brunauer, Emmett and Teller method (BET), Scanning Electron Microscopy (SEM) and simultaneous Thermo-Gravimetric and Differential Thermal Analysis (TGA/DTA). These techniques indicate that the Gh consists essentially of steveniste, calcite, dolomite and quartz. The study of the interfacial electrochemical properties of Gh in different solutions of electrolyte salts (NaCl, CsCl, NaF, NaBr and LiCl) was carried out using the potentiometric and conductometric titrations It was shown that the Gh particles were stable in aqueous phase within the pH range (3-12) and the point of zero charge (PZC) was located at pH = 10.7. The adsorption sequence, carried out at various ionic strengths, showed that the adsorption mechanism onto the Gh particles is both electrostatic and specific at pH below the pH, while at a pH range greater than the pH the mechanism is electrostatic in nature. The total number of surface sites, determined using the graphical extrapolation method, was 11OH/nm. Ionization constants ( and ) in the presence of various electrolytes have also been determined and their values are 10.08 and 12.38, respectively.
一种当地名为“Ghassoul”（Gh）的摩洛哥原生黏土，采用了多种技术进行表征，如傅里叶变换红外光谱法（FTIR）、X射线衍射法（XRD）、布鲁诺尔-埃米特-泰勒法（BET）、扫描电子显微镜法（SEM）以及同步热重分析和差示热分析法（TGA/DTA）。这些技术表明，Gh主要由硅铁石、方解石、白云石和石英组成。使用电位滴定法和电导滴定法对Gh在不同电解质盐溶液（NaCl、CsCl、NaF、NaBr和LiCl）中的界面电化学性质进行了研究。结果表明，Gh颗粒在pH范围（3 - 12）的水相中是稳定的，零电荷点（PZC）位于pH = 10.7。在不同离子强度下进行的吸附序列表明，在低于pH值时，Gh颗粒上的吸附机制既有静电作用又有特异性作用，而在高于pH值的范围内，吸附机制本质上是静电作用。使用图形外推法确定的表面位点总数为11OH/nm。还测定了在各种电解质存在下的电离常数（ 和 ），其值分别为10.08和12.38。
