Key Laboratory of Regional Environment and Eco-Remediation, Ministry of Education, Shenyang University, Shenyang, 110044, China.
Environ Sci Pollut Res Int. 2018 Jul;25(21):21036-21048. doi: 10.1007/s11356-018-2282-x. Epub 2018 May 16.
In this study, the magnetic reduced graphene oxide (RGO/FeO), with easy separation and high adsorption performance, was prepared and used to treat glyphosate (GLY) contaminated water. GLY adsorption performance of RGO/FeO was investigated, and influences of pH, adsorption time, temperature, contaminant concentration, and competing anions were analyzed. Moreover, the adsorption mechanism was discussed in the light of several characterization methods, including scanning electron microscopy (SEM), energy dispersive spectrum (EDS), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The results demonstrated that the RGO/FeO presented a significant GLY adsorption capacity and acid condition was beneficial for this adsorption. The pseudo-second-order kinetic model and the Langmuir model correlated satisfactorily to the experimental data, indicating that this process was controlled by chemical adsorption and monolayer adsorption. Thermodynamic studies revealed that the adsorption of glyphosate onto RGO/FeO was spontaneous, endothermic, and feasible process. High temperatures were beneficial to GLY adsorption. The GLY adsorption mechanism of RGO/FeO was mainly attributed to hydrogen-bond interaction, electrostatic interaction, and coordination. Therefore, the RGO/FeO investigated in this research may offer an attractive adsorbent candidate for treatment of glyphosate contaminated water and warrant further study as a mechanism for glyphosate efficient removal.
在这项研究中，制备了具有易于分离和高吸附性能的磁性还原氧化石墨烯（RGO/FeO），并将其用于处理草甘膦（GLY）污染的水。研究了 RGO/FeO 对 GLY 的吸附性能，分析了 pH 值、吸附时间、温度、污染物浓度和竞争阴离子的影响。此外，还通过扫描电子显微镜（SEM）、能谱（EDS）、傅里叶变换红外光谱（FTIR）和 X 射线光电子能谱（XPS）等几种表征方法探讨了吸附机理。结果表明，RGO/FeO 对 GLY 具有显著的吸附能力，酸性条件有利于这种吸附。准二级动力学模型和 Langmuir 模型与实验数据吻合较好，表明该过程受化学吸附和单层吸附控制。热力学研究表明，草甘膦在 RGO/FeO 上的吸附是自发的、吸热的和可行的过程。高温有利于 GLY 的吸附。RGO/FeO 对 GLY 的吸附机理主要归因于氢键相互作用、静电相互作用和配位。因此，本研究中所研究的 RGO/FeO 可能为处理草甘膦污染水提供了一种有吸引力的吸附剂候选物，并值得进一步研究以了解草甘膦的有效去除机制。
