Laboratoire de Catalyse et Corrosion des Matériaux LCCM, Université Chouaïb Doukkali, Faculté des Sciences El Jadida, BP. 20, El Jadida, 24000, Morocco.
Laboratoire Matériaux et Environnement LME, Faculté des Sciences, Université Ibn Zohr, BP 8106, Cité Dakhla, Agadir, Morocco.
Chemosphere. 2019 Sep;231:140-150. doi: 10.1016/j.chemosphere.2019.05.120. Epub 2019 May 17.
Carbon microspheres were synthesized under nitrogen flow from walnut shells (WS) and then used as an adsorbent for the removal of Pb (II), Cu(II), Cr(III) and Cd(II) metals. The prepared material was characterized using X-ray photoelectron spectroscopy, scanning electron microscopy, Brounauer-emett-teller surface, Fourier transform infrared and Raman spectroscopy. SEM micrographs showed homogenous sphere-like structure with an average diameter of 4.55 μm. The prepared carbon microspheres exhibit selective and rapid removal of hazardous metals from synthetic water samples. The effects of solution pH, contact time and temperatures on the removal process have been systematically investigated. The material used in this present work present the highest adsorption capacities ever reported for Cr(III), Pb(II), Cd(II) and Cu(II) at an optimum pH of 5, the adsorption capacities reached 792, 638, 574 and 345 mg g for Cr(III), Pb(II), Cd(II) and Cu(II), respectively. Density functional calculations (DFT) showed an agreement with the adsorption process results, Cr(III) had stronger binding ability to the OH and/or COOH functional groups followed by Pb, Cu and Cd. The adsorption mechanism was discussed based on the experimental and theoretical results. Finally, the response surface methodology was used to optimize the adsorption conditions.
从核桃壳（WS）在氮气流下合成了碳微球，然后将其用作吸附剂，用于去除 Pb(II)、Cu(II)、Cr(III) 和 Cd(II) 金属。使用 X 射线光电子能谱、扫描电子显微镜、Brounauer-emett-teller 表面、傅里叶变换红外和拉曼光谱对制备的材料进行了表征。SEM 显微照片显示出均匀的球形结构，平均直径为 4.55 μm。所制备的碳微球对合成水样中的有害金属具有选择性和快速去除作用。系统研究了溶液 pH 值、接触时间和温度对去除过程的影响。本工作中使用的材料在最佳 pH 值为 5 时，对 Cr(III)、Pb(II)、Cd(II) 和 Cu(II) 的吸附容量达到了前所未有的最高值，分别为 792、638、574 和 345 mg/g。密度泛函计算 (DFT) 结果与吸附过程结果一致，Cr(III)与 OH 和/或 COOH 官能团的结合能力更强，其次是 Pb、Cu 和 Cd。根据实验和理论结果讨论了吸附机理。最后，使用响应面法优化了吸附条件。
