Abstract

A chitosan polymer was magnetized by coating with magnetite Fe₂O₃ nanoparticles, and the resultant material (C-Fe₂O₃) was first characterized through scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy, transmission electron microscopy, atomic force microscopy, thermogravimetric, X-ray diffractometry, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller, and point of zero charge analyses. C-Fe₂O₃ was then employed as a separable and efficient adsorptive agent to remove acid blue 113 (AB113) dye from aqueous solution. The removal efficiency was optimized at different environmental parameter values (pH 3–11, C-Fe₂O₃ dose: 0.1–1 g/L, initial AB113 dye concentration: 10–100 mg/L, adsorption time: 0–300 min, and temperature: 15–45 °C). Under optimum conditions, an AB113 dye removal efficiency of 99.68% was achieved. In addition, the effect of the presence of NaCl, NaNO₃, Na₂CO₃, and MgSO₄ ions on the AB113 dye removal efficiency could be ranked as NaCl > NaNO₃ > MgSO₄ > Na₂CO₃. The statistical analysis using the coefficient of determination, root mean square error, chi-square test, sum of squared errors, and average relative error showed that the Freundlich and pseudo-second-order equations were the best mathematical models for fitting the isothermal and kinetics data. Further kinetics analyses showed that the adsorption of AB113 molecules on C-Fe₂O₃ active sites was dominated by the intraparticle diffusion process. Thermodynamic parameters indicated that the AB113 dye adsorption process was favorable, endothermic, and spontaneous. Furthermore, an increase in temperature had a positive impact on AB113 dye removal. The regeneration study confirmed the excellent shelf life of C-Fe₂O₃, with only a slight loss in the removal efficiency (< 7%) being detected after six operational cycles of AB113 dye adsorption. Compared with other adsorbents, C-Fe₂O₃ was more effective for the adsorption of AB113 dye, with an adsorption uptake up to 128 mg/g.

Graphic Abstract

中文翻译：

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酸性蓝 113 染料吸附在 Fe2O3 纳米颗粒磁化壳聚糖上的能力和建模

摘要

通过涂覆磁铁矿 Fe ₂ O ₃纳米粒子对壳聚糖聚合物进行磁化，并首先通过配备能量色散 X 射线光谱、透射电子显微镜、原子力的扫描电子显微镜表征所得材料（C-Fe ₂ O ₃）显微镜、热重分析、X 射线衍射、傅里叶变换红外光谱、Brunauer-Emmett-Teller 和零电荷点分析。然后使用C-Fe ₂ O ₃作为可分离且有效的吸附剂以从水溶液中去除酸性蓝 113 (AB113) 染料。在不同的环境参数值（pH 3-11，C-Fe ₂ O₃剂量：0.1–1 g/L，初始 AB113 染料浓度：10–100 mg/L，吸附时间：0–300 分钟，温度：15–45 °C）。在最佳条件下，AB113 染料去除效率达到 99.68%。此外，NaCl、NaNO ₃、Na ₂ CO ₃和MgSO ₄离子对AB113染料去除效率的影响可以排列为NaCl > NaNO ₃  > MgSO ₄  > Na ₂ CO ₃. 使用决定系数、均方根误差、卡方检验、误差平方和和平均相对误差的统计分析表明，Freundlich方程和伪二阶方程是拟合等温和动力学的最佳数学模型。数据。进一步的动力学分析表明，AB113 分子在 C-Fe ₂ O ₃活性位点上的吸附主要受颗粒内扩散过程的影响。热力学参数表明AB113染料吸附过程是有利的、吸热的和自发的。此外，温度升高对 AB113 染料去除具有积极影响。再生研究证实了 C-Fe ₂ O ₃优异的保质期，在 AB113 染料吸附的六个操作循环后仅检测到去除效率的轻微损失（< 7%）。与其他吸附剂相比，C-Fe ₂ O ₃对AB113染料的吸附更有效，吸附量可达128 mg/g。

图形摘要