Abstract

Magnetic nanoparticles and clay minerals combine to form a class of advanced nanocomposites that would possess exceptional adsorption, magnetism, and stability. In this work, an environmentally friendly nanocomposite was successfully fabricated by functionalizing natural clay. Bentonite сlay/meghemite nanocomposite was synthesized by the co-precipitation method and used to Methyl Orange pollutant removal as a toxic anionic dye from aqueous solutions. Physical and structural characteristics of the synthesized adsorbent were assessed using different techniques including Fourier transform infrared spectrometer, scanning electron microscopy, vibrating sample magnetometry, and X-ray diffraction. The saturation magnetization of maghemite and bentonite/maghemite nanocomposite are 50.9 and 28.5 emu g^–1, respectively. The average size of the synthesized maghemite nanoparticles calculated by the Scherer equation was 16.60 nm. Different kinetic and thermodynamic models and isotherms of the adsorption process were also investigated. The adsorption capacity became equilibrium after 120 min. The consistency of the adsorption process with the pseudo-second-order kinetic model was confirmed by studying its kinetic data. Investigating the equilibrium isotherm data at different temperatures showed better compatibility with the Freundlich model. The negative values of ΔG and positive values of ΔH obtained from adsorption thermodynamic study revealed that Methyl Orange adsorption from aqueous samples is spontaneous and endothermic. The optimal parameters for Methyl Orange removal by synthesized adsorbent were determined by MINITAB 17 under response surface methodology (RSM). The maximum adsorption capacity of dye adsorption of 56.79 mg g^–1 was obtained under optimum conditions of pH = 4, adsorbent dose of 1 g L^–1 and dye concentration of 90 mg L^–1.

中文翻译：

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超顺磁性粘土/磁赤铁矿纳米复合材料吸附阴离子染料的响应面法优化

摘要

磁性纳米粒子和粘土矿物结合形成一类具有卓越吸附性、磁性和稳定性的先进纳米复合材料。在这项工作中，通过对天然粘土进行功能化，成功制备了一种环保的纳米复合材料。膨润土сlay/ meghemite纳米复合材料通过共合成-沉淀法和用于甲基橙污染物去除作为从水溶液中有毒阴离子染料。合成吸附剂的物理和结构特征使用不同的技术进行评估，包括傅里叶变换红外光谱仪、扫描电子显微镜、振动样品磁强计和 X 射线衍射。磁赤铁矿和膨润土/磁赤铁矿纳米复合材料的饱和磁化强度分别为 50.9 和 28.5 emu g ^–1， 分别。由谢勒方程计算的合成磁赤铁矿纳米颗粒的平均尺寸为 16.60 nm。还研究了吸附过程的不同动力学和热力学模型以及等温线。吸附容量在 120 分钟后达到平衡。通过研究其动力学数据，证实了吸附过程与拟二级动力学模型的一致性。研究不同温度下的平衡等温线数据表明与 Freundlich 模型具有更好的兼容性。Δ G的负值和 Δ H 的正值从吸附热力学研究中获得的结果表明，从水样中吸附甲基橙是自发的和吸热的。合成吸附剂去除甲基橙的最佳参数由 MINITAB 17 在响应面法 (RSM) 下确定。的56.79毫克克染料吸附的最大吸附容量^-1 pH值= 4，1克L-吸附剂剂量的最佳条件下得到^-1和染料的90毫克L的浓度^-1。