生物炭
吸附
化学
六价铬
X射线光电子能谱
吸热过程
化学吸附
氧化还原
傅里叶变换红外光谱
弗伦德利希方程
无机化学
铬
碳纤维
红外光谱学
物理化学
化学工程
材料科学
有机化学
热解
复合材料
工程类
复合数
作者
Xiaoli Guo,Aiju Liu,Jie Lü,Xiaoyin Niu,Man Jiang,Yanfei Ma,Xinpeng Liu,Menghong Li
出处
期刊:ACS omega
[American Chemical Society]
日期:2020-10-19
卷期号:5 (42): 27323-27331
被引量:56
标识
DOI:10.1021/acsomega.0c03652
摘要
The adsorption mechanism of Cr6+ on biochar prepared from corn stalks (raw carbon) was studied by extracting the organic components (OC) and inorganic components (IC). Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy were used to characterize the properties of three kinds of carbon. Kinetic and thermodynamic experiments were performed. The results showed that the experimental data were fitted well by the Freundlich model and the pseudo-second-order kinetic model, and the adsorptions on the three kinds of carbon were all spontaneous, endothermic processes. The adsorption of Cr6+ by biochar was in accordance with a chemisorption process. The adsorption contribution rate of the OC was 97%, which was much higher than that of the IC. Electrostatic attraction and redox reaction were the main mechanisms of adsorption, and among them, the contribution rate of the redox reaction accounted for 61.49%. The reduced Cr3+ could both exchange ions with K+ and dissociate into solution by electrostatic repulsion; the amount of Cr3+ released into the solution was approximately 17.07 mg/g, and the amount of Cr3+ ions exchanged with K+ was 0.29 mg/g. These results further elucidate the adsorption mechanism of Cr6+ by biochar.
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