Department of Chemistry, Jamia Millia Islamia, Jamia Nagar, New Delhi, 110 025, India.
Department of Chemistry, Jamia Millia Islamia, Jamia Nagar, New Delhi, 110 025, India.
Chemosphere. 2022 Feb;289:133232. doi: 10.1016/j.chemosphere.2021.133232. Epub 2021 Dec 8.
Herein, a functionalized green hydrogel nanocomposite based on carboxymethylated gum tragacanth and nanobentonite (GTBCH) was designed via free-radical polymerization approach for the elimination of Aspartame (AS) from wastewater. The GTBCH fabrication was validated by Fourier Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) techniques. Central composite design (CCD) was efficaciously applied to determine the quadratic polynomial approach for predicting the adsorption capacity (q) of AS. The optimum sequestration conditions were dosage (0.8 g L), agitation time (35 min) initial AS concentration (60 mg L), pH (6) and temperature (308 K). The CCD results revealed that dosage of GTBCH and initial concentration have greater impact on q followed by pH, time, and temperature. The significant adsorption capacity (392.04 mg g), calculated from Langmuir model, could be attributed to the stronger interactions prevalent between AS and GTBCH. Diffusion investigations depicted the uptake of AS via surface adsorption, liquid film and intraparticle diffusion, respectively. Ionic strength and real water have minor effect on the adsorption capacity demonstrating electrostatic interaction has least impact in adsorption process. The pHzpc, FTIR and XPS investigations revealed hydrogen bonding, n-π and van der Waals interactions as the principal removal mechanisms. Robust design, high adsorption capacity, eco-friendly facets along with excellent reusability indicated the GTBCH as a competent adsorbent for AS decontamination from wastewater.
本文通过自由基聚合方法设计了一种基于羧甲基胍胶和纳米膨润土的功能化绿色水凝胶纳米复合材料（GTBCH），用于从废水中去除阿斯巴甜（AS）。通过傅里叶变换红外光谱（FTIR）、X 射线衍射（XRD）、X 射线光电子能谱（XPS）、透射电子显微镜（TEM）、扫描电子显微镜（SEM）和能谱（EDX）技术对 GTBCH 的制备进行了验证。中心复合设计（CCD）有效地应用于确定预测 AS 吸附容量（q）的二次多项式方法。最佳螯合条件为剂量（0.8 g/L）、搅拌时间（35 min）、初始 AS 浓度（60 mg/L）、pH（6）和温度（308 K）。CCD 结果表明，GTBCH 的剂量和初始浓度对 q 的影响较大，其次是 pH、时间和温度。从 Langmuir 模型计算出的显著吸附容量（392.04 mg/g）归因于 AS 和 GTBCH 之间存在较强的相互作用。扩散研究表明，AS 的摄取分别通过表面吸附、液膜和颗粒内扩散进行。离子强度和实际水对吸附容量的影响较小，表明静电相互作用在吸附过程中的影响最小。pHzpc、FTIR 和 XPS 研究表明，氢键、n-π 和范德华相互作用是主要的去除机制。稳健设计、高吸附容量、环保方面以及出色的可重复使用性表明 GTBCH 是一种从废水中去除 AS 的有竞争力的吸附剂。
