Department of Chemistry, Jamia Millia Islamia, Jamia Nagar, New Delhi 110 025, India.
Langmuir. 2022 Jul 12;38(27):8280-8295. doi: 10.1021/acs.langmuir.2c00702. Epub 2022 Jun 27.
In the present investigation, a novel, green, and economical dual-functionalized pullulan/kaolin hydrogel nanocomposite (-PKHN) was fabricated and subsequently applied for the liquid-phase decontamination of paracetamol (PCT), a pharmaceutical pollutant. Pullulan and kaolin were functionalized with l-asparagine and gallic acid, respectively. The physicochemical facets of the functionalized pullulan/kaolin hydrogel nanocomposite and its interactive behavior with PCT were elucidated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), and elemental mapping. The process parameters along with the isotherm, kinetics, and thermodynamics were methodically appraised via a batch technique to unveil the adsorption performance of the as-fabricated hydrogel nanocomposite. The adsorption isotherm and kinetics of PCT uptake by -PKHN conform well to Freundlich and pseudo-second-order models, respectively. Relying on hydrogen bonding, n-π, and van der Waals interactions, the maximum adsorption capacity was 332.54 mg g, higher than for most of the previous adsorbents reported in the literature for PCT removal. Thermodynamic calculations corroborated endothermic, spontaneous, and feasible adsorption phenomena. The maintenance of a high uptake percentage (69.11%) in the fifth consecutive adsorption-desorption cycle implied the significant reusable potential of -PKHN. Swelling studies exhibited 90% swelling within 200 min, indicating the successful fabrication of a cross-linked hydrogel network. The real water (distilled water, tap water, and river water) samples spiked with PCT specified a significant uptake of PCT (>85%), and the minor influence of ionic strength on the adsorptive potential of -PKHN validated its potentiality for the decontamination of real effluents. In conclusion, -PKHN with substantial adsorption capacity, green characteristics, and excellent reusability can be reckoned with as a promising adsorbent for the de-escalation of PCT from aquatic sources as well as at the industrial level.
在本研究中，制备了一种新颖、绿色、经济的双功能化普鲁兰/高岭土水凝胶纳米复合材料（-PKHN），并将其应用于液相中对乙酰氨基酚（PCT）这种药物污染物的净化。普鲁兰和高岭土分别用 L-天冬酰胺和没食子酸进行了功能化。通过 X 射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、X 射线光电子能谱（XPS）、透射电子显微镜（TEM）、扫描电子显微镜-能量色散 X 射线光谱（SEM-EDX）和元素映射对功能化普鲁兰/高岭土水凝胶纳米复合材料的物理化学特征及其与 PCT 的相互作用行为进行了阐述。通过批处理技术系统地评估了过程参数以及等温线、动力学和热力学，以揭示所制备水凝胶纳米复合材料的吸附性能。-PKHN 对 PCT 的吸附等温线和动力学符合 Freundlich 和准二级模型。基于氢键、n-π 和范德华相互作用，最大吸附容量为 332.54mg/g，高于文献中报道的大多数用于去除 PCT 的先前吸附剂。热力学计算证实了吸附是吸热、自发和可行的现象。在第五次连续吸附-解吸循环中保持高吸附率（69.11%）表明 -PKHN 具有显著的可重复使用潜力。溶胀研究表明，在 200 分钟内溶胀率达到 90%，表明成功制备了交联水凝胶网络。用 PCT 对实际水样（蒸馏水、自来水和河水）进行了加标，结果表明，-PKHN 对 PCT 的去除率很高（>85%），并且 -PKHN 的吸附性能受离子强度的影响较小，这验证了其在实际废水处理中的应用潜力。总之，-PKHN 具有较高的吸附容量、绿色特性和出色的可重复使用性，可作为一种有前途的吸附剂，用于从水相中以及工业水平降低 PCT 的浓度。
