Environmental Chemistry Research Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi, India.
Environmental Chemistry Research Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi, India.
Environ Res. 2019 Nov;178:108667. doi: 10.1016/j.envres.2019.108667. Epub 2019 Aug 16.
In this work, an advance approach is reported for the water treatment technology using nanohybrid composite FeO-SnO/BC prepared by incorporation of iron-tin binary oxide into the cellulosic framework of medicinally active Nigella sativa (Black cumin) seed powder. The co-precipitation method was followed to prepare the nanohybrid composite which was subjected to investigate its physiochemical properties using spectroscopic and microscopic techniques. Fourier-transform infrared spectroscopy analysis confirmed the formation of highly functionalized nanocomposite through the hydrogen and electrostatic interactions between the functional groups of seeds and FeO-SnO. X-ray and selected area electron diffraction pattern revealed the presence of cubic phase of γ-FeO and tetragonal phase of SnO in the composite. The scanning electron microscopic images suggested the porous and relatively smooth surface of the composite, and transmittance electron microscopic images showed the trapping of nano-cubes of FeO-SnO, having particles size in the range 95-185 nm, into the organic framework of Black cumin seeds, whose zero point charge was found at pH 7.2. The composite was investigated for adsorption of Methylene blue dye from water for which the results revealed that 2.0 gL amount of FeO-SnO/BC was sufficient to remove more than 95% dye, within 15 min, at 6-9 pH, from its 10 mgL concentration. The thermodynamic studies established spontaneity, feasibility, and endothermic nature of the adsorption process. The adsorption data was satisfactorily described by the Freundlich isotherm which indicated inhomogeneous surface of the composite. Application of Temkin isotherm revealed the same extent of bonding probability and heat of adsorption at 27, 35, and 45 °C. The free energy change calculated from Dubinin-Radushkevich isotherm suggested weak interaction between Methylene blue and FeO-SnO/BC. The process satisfactorily followed the pseudo-second order kinetics that was controlled by the film diffusion step which indicated interaction of Methylene blue with functional sites of the FeO-SnO/BC. The Fourier-transform infrared spectroscopy analysis gave the confirmatory evidence for interaction of Methylene blue to FeO-SnO/BC. The maximum Langmuir adsorption capacity of the FeO-SnO/BC was found to be 58.82 mgg at 27 °C which is higher than the previously reported adsorbents, MnFeO/BC [J. Clean. Prod. 2018. 200, 996-1008], and FeO-ZrO/BC [J. Clean. Prod. 2019. 223, 849-868]. Therefore, the study showed excellent results for water treatment and can be useful to develop advance water treatment technology.
在这项工作中，报道了一种使用纳米杂化复合材料 FeO-SnO/BC 的水处理技术的先进方法，该复合材料是通过将铁锡二元氧化物掺入药用活性黑种草（黑孜然）种子粉末的纤维素骨架中制备的。采用共沉淀法制备纳米杂化复合材料，并通过光谱和显微镜技术研究其物理化学性质。傅里叶变换红外光谱分析证实，通过种子和 FeO-SnO 官能团之间的氢键和静电相互作用，形成了高度功能化的纳米复合材料。X 射线和选区电子衍射图表明，复合材料中存在立方相的 γ-FeO 和四方相的 SnO。扫描电子显微镜图像表明复合材料具有多孔且相对光滑的表面，而透射电子显微镜图像表明纳米立方 FeO-SnO 被捕获到黑孜然种子的有机骨架中，其零电荷点在 pH 7.2 时。该复合材料用于从水中吸附亚甲基蓝染料，结果表明，在 6-9 pH 时，2.0 gL 的 FeO-SnO/BC 足以在 15 分钟内从 10 mgL 的浓度中去除超过 95%的染料。热力学研究确定了吸附过程的自发性、可行性和吸热性质。吸附数据被 Freundlich 等温线很好地描述，表明复合材料的表面不均匀。应用 Temkin 等温线表明，在 27、35 和 45°C 时，键合概率和吸附热相同。从 Dubinin-Radushkevich 等温线计算的自由能变化表明，亚甲基蓝与 FeO-SnO/BC 之间的相互作用较弱。该过程很好地遵循了准二级动力学，该动力学受膜扩散步骤控制，表明亚甲基蓝与 FeO-SnO/BC 的官能团相互作用。傅里叶变换红外光谱分析为亚甲基蓝与 FeO-SnO/BC 的相互作用提供了确证证据。在 27°C 时，FeO-SnO/BC 的最大朗缪尔吸附容量被发现为 58.82 mgg，高于之前报道的吸附剂 MnFeO/BC[J. Clean. Prod. 2018. 200, 996-1008]和 FeO-ZrO/BC[J. Clean. Prod. 2019. 223, 849-868]。因此，该研究在水处理方面取得了优异的结果，可用于开发先进的水处理技术。
