Zakaria Anfar, Amane Jada, Noureddine El Alem
Materials and Environment Laboratory, Ibn Zohr University Agadir 8000 Morocco
Mulhouse Materials Science Institute - CNRS, University Haute Alsace F-68100 Mulhouse France.
RSC Adv. 2019 Aug 15;9(44):25544-25553. doi: 10.1039/c9ra04869c. eCollection 2019 Aug 13.
The overall goal of this work was to activate agri-food wastes by microbial action, which makes it possible to produce bio-digestate and energy (methane). The resulting bio-digestate could be transformed to porous carbon (PC), which was used for the preparation of core-shell particles with alginate (bio-polymer) and a calcium ion layer. Furthermore, surface charge measurements showed electrostatic attractions occurring between the alginate, calcium (Ca) ions and the PC, hence leading to the formation of core (PC)-shell (alginate-calcium ions) particles. However, in the absence of calcium ions, no electrostatic attractions were observed between the PC and the alginate. In the dried state (using scanning electronic microscopy analysis (SEM)) and in the hydrate state (using numerical microscopy), the designed core-shell architecture was confirmed. Transmission electron microscopy (TEM) shows that the PC particles were graphitic and porous. In addition, both Raman spectroscopy (RS) and X-ray photoelectron spectroscopy (XPS) showed the presence of several chemical functions, in particular hydroxyl (-O-H) and carboxylic groups (-COO-H). In aqueous media, the results showed that the PC was negatively charged and its surface charge and particle size were found to be very sensitive to the variation in pH. Finally, the core-shell particles were used as an adsorbent for the removal of methylene blue (MB), crystal violet (CV) and congo red (CR) molecules from wastewater. The overall data indicated efficient dye removal, without the occurrence of the solid/liquid separation problem.
这项工作的总体目标是通过微生物作用激活农业食品废弃物，从而有可能生产生物沼渣和能源（甲烷）。产生的生物沼渣可以转化为多孔碳（PC），用于制备含有藻酸盐（生物聚合物）和钙离子层的核壳颗粒。此外，表面电荷测量表明藻酸盐、钙离子和PC之间存在静电吸引力，从而导致形成核（PC）-壳（藻酸盐-钙离子）颗粒。然而，在没有钙离子的情况下，未观察到PC和藻酸盐之间存在静电吸引力。在干燥状态（使用扫描电子显微镜分析（SEM））和水合状态（使用数字显微镜）下，所设计的核壳结构得到了证实。透射电子显微镜（TEM）显示PC颗粒呈石墨状且多孔。此外，拉曼光谱（RS）和X射线光电子能谱（XPS）均显示存在多种化学官能团，特别是羟基（-O-H）和羧基（-COO-H）。在水性介质中，结果表明PC带负电荷，并且发现其表面电荷和粒径对pH值变化非常敏感。最后，核壳颗粒被用作吸附剂，用于去除废水中的亚甲基蓝（MB）、结晶紫（CV）和刚果红（CR）分子。总体数据表明染料去除效率高，且不存在固/液分离问题。
