Faculty of Sciences, Chemistry Department, Alexandria University, P.O. Box 426, Ibrahimia 21321, Alexandria, Egypt.
Faculty of Sciences, Chemistry Department, Alexandria University, P.O. Box 426, Ibrahimia 21321, Alexandria, Egypt.
J Colloid Interface Sci. 2022 Oct 15;624:602-618. doi: 10.1016/j.jcis.2022.05.132. Epub 2022 Jun 4.
Recent progress in nanotechnology via incorporation of small particle size as quantum dots (QDs) (1-10 nm) in many industrial activities and commercial products has led to significant undesired environmental impacts. Therefore, QDs removal from wastewater represents an interesting research topic with a lot of challenges for scientists and engineers nowadays. In this work, the coagulative removal of metal quantum dots as silver and gold from industrial water samples is explored. A novel biosorbent was assembled via binding of covalent organic frameworks (COFs) with magnetic zeolite and Arabic gum hydrogel (COFs@MagZ@AGH) as a promising removal material for Ag-QDs and Au-QDs. This was fully characterized by EDX, SEM, TEM, FT-IR, XPS, XRD and surface area and applied in coagulative removal of Au-QDs and Ag-QDs in presence of several experimental factors as pH, presence of other electrolytes, stirring time, initial QDs concentration, coagulant dosage, and temperature in order to optimize the removal processes. At optimum conditions, COFs@MagZ@AGH was able to recover 99.19% and 87.57% of Ag-QDs and Au-QDs QDs, respectively via chemical adsorption mechanism with perfect fitting to pseudo-second order model. Reuse of the recovered Ag/Au-QDs@COFs@MagZ@AGH as efficient catalysts in catalytic degradation of Rifampicin antibiotic (Rf) from water was additionally investigated and optimized via microwave-Fenton catalysts with excellent oxidative degradation efficiency (100%). Reusability and applicability of the biosorbent (COFs@MagZ@AGH) and catalysts (Ag/Au-QDs@COFs@MagZ@AGH) in real industrial water samples were also explored and successfully accomplished.
近年来，通过将小粒径（1-10nm）的量子点（QDs）纳入许多工业活动和商业产品中，纳米技术取得了显著进展，但也导致了一些不良的环境影响。因此，从废水中去除 QDs 成为了当前科学家和工程师们关注的一个研究热点，同时也面临着许多挑战。在这项工作中，探索了通过将共价有机框架（COFs）与磁性沸石和阿拉伯树胶水凝胶（COFs@MagZ@AGH）结合来去除工业水样中金属量子点（如银和金）的凝聚去除方法。通过 EDX、SEM、TEM、FT-IR、XPS、XRD 和表面积等方法对 COFs@MagZ@AGH 进行了全面表征，并将其作为一种有前途的去除 Ag-QDs 和 Au-QDs 的材料进行了应用。考察了 pH 值、共存电解质、搅拌时间、初始 QDs 浓度、混凝剂用量和温度等多种实验因素对 Au-QDs 和 Ag-QDs 凝聚去除过程的影响，以优化去除过程。在最佳条件下，通过化学吸附机制，COFs@MagZ@AGH 能够分别回收 99.19%和 87.57%的 Ag-QDs 和 Au-QDs，且对伪二级模型拟合完美。此外，还研究了从水中催化降解利福平抗生素（Rf）的微波-Fenton 催化剂中回收的 Ag/Au-QDs@COFs@MagZ@AGH 作为高效催化剂的重复使用性能，并对其进行了优化，具有优异的氧化降解效率（100%）。还探索并成功完成了实际工业水样中生物吸附剂（COFs@MagZ@AGH）和催化剂（Ag/Au-QDs@COFs@MagZ@AGH）的可重复使用性和适用性。
