Abstract The presence of free fatty acid (FFA) in waste vegetable oil (WVO) is undesired and must be removed. The present study synthesized amine imprinted manganese ferrite (MnFe2O4-DEA) via coprecipitation method and used it for the removal of FFA in WVO. Fourier transformed Infrared spectroscopy (FTIR) and X-ray diffraction (XRD) results confirmed the formation of MnFe2O4-DEA and further analysis by Brunauer-Emmett-Teller (BET) surface area showed the nanoparticles possessed a surface area of 20.64 m² g−1. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) revealed elemental composition and surface morphology. MnFe2O4-DEA showed promising results of FFA separation, recording 99.57% removal rate. The process obeyed langmuir isotherm and can be described by pseudo-second-order kinetic model. The values of Gibb's free energy change (∆Go) decreased with increase in temperature, the entropy change (∆So) was positive while enthalpy change (∆Ho) value suggested an endothermic sorption process. The mechanism for the removal of FFA by MnFe2O4-DEA may have occurred by simple chemical bonding, which could be described as donor-acceptor interaction by quantum chemical analysis.

中文翻译：

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胺印迹铁酸锰的合成及其在去除废植物油中游离脂肪酸中的应用

摘要 废植物油 (WVO) 中游离脂肪酸 (FFA) 的存在是不受欢迎的，必须去除。本研究通过共沉淀法合成了胺印迹锰铁氧体 (MnFe2O4-DEA) 并将其用于去除 WVO 中的 FFA。傅里叶变换红外光谱 (FTIR) 和 X 射线衍射 (XRD) 结果证实了 MnFe2O4-DEA 的形成，Brunauer-Emmett-Teller (BET) 表面积的进一步分析表明纳米颗粒的表面积为 20.64 m² g-1 . 扫描电子显微镜 (SEM)、透射电子显微镜 (TEM) 和能量色散 X 射线光谱 (EDX) 揭示了元素组成和表面形态。MnFe2O4-DEA 表现出良好的 FFA 分离效果，去除率达 99.57%。该过程服从langmuir等温线，可以用拟二级动力学模型描述。Gibb 自由能变化 (ΔGo) 值随温度升高而降低，熵变 (ΔSo) 为正，而焓变 (ΔHo) 值表明吸热过程。MnFe2O4-DEA 去除 FFA 的机制可能是通过简单的化学键合发生的，这可以通过量子化学分析描述为供体-受体相互作用。