Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, China.
Institute of Water Resources and Environment, Jilin University, Changchun, 130021, China.
Environ Sci Pollut Res Int. 2018 Sep;25(26):26173-26181. doi: 10.1007/s11356-018-2410-7. Epub 2018 Jun 2.
Sponge iron particles modified with expanded graphite and Cu were used to purify solutions contaminated with aqueous Cr(VI). A removal mechanism that involved physical adsorption and a redox reaction is proposed. The reaction, which consisted of rapid adsorption, a desorption stage, and an adsorption-desorption equilibrium stage, corresponded to a first-order kinetic model. The properties of the adsorption materials before and after use were investigated by X-ray diffraction, scanning electron microscopy-energy-dispersive spectroscopy, Fourier-transform infrared spectroscopy, energy-dispersive X-ray fluorescence spectroscopy, and surface area measurements. Changes in the surface properties, e.g., attachment of material to the surface and filling of pores with Cr, were clearly observed. The Langmuir model best described Cr(VI) adsorption on the sponge iron and its modified particles. Removal efficiencies of 98.7, 98.8, and 100% were achieved in 7 h at a Cr(VI) dosage of 10 mg/L. Sponge iron particles are therefore potential adsorbents and after modification give good removal of Cr(VI) ions from contaminated water.
用膨胀石墨和 Cu 改性的海绵铁颗粒用于净化含水溶液 Cr(VI)的溶液。提出了一种涉及物理吸附和氧化还原反应的去除机制。该反应由快速吸附、解吸阶段和吸附-解吸平衡阶段组成，符合一级动力学模型。通过 X 射线衍射、扫描电子显微镜-能谱、傅里叶变换红外光谱、能谱 X 射线荧光光谱和表面积测量研究了使用前后吸附材料的性质。可以清楚地观察到表面性质的变化，例如材料附着在表面上以及 Cr 填充孔。Langmuir 模型很好地描述了 Cr(VI)在海绵铁及其改性颗粒上的吸附。在 7 h 内，Cr(VI)剂量为 10 mg/L 时，去除效率达到 98.7%、98.8%和 100%。因此，海绵铁颗粒是潜在的吸附剂，经过改性后可以很好地去除受污染水中的 Cr(VI)离子。
