Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China.
Water Res. 2010 Apr;44(8):2517-24. doi: 10.1016/j.watres.2010.01.027. Epub 2010 Feb 1.
This study describes the modification of aerobic granules by grafting polyethylenimine (PEI) for simultaneous sorption and detoxification of Cr(VI). After modification, the uptake capacity of modified aerobic granules (MAG) showed about 401.5 mg/g at pH 5.5 and increased by 274% compared to the control. Adsorption experiments were carried out as a function of contact time, pH and concentration of Cr(VI). It was found that the equilibrium sorption can be attained within 3 h and the process obeys the Redlich-Peterson isotherm model. The adsorption process is a function of pH of the solution, with the greater adsorption at pH 5.2. The interaction characteristics between the Cr and MAG were elucidated by applying FTIR and XPS analyses. FTIR results showed that the -NH2 groups in the sorbent are involved in the adsorption process. XPS results verified the presence of Cr(III) on the MAG surface in the pH range 1.5-8.5, suggesting that some Cr(VI) anions were reduced to Cr(III) during the sorption.
本研究通过接枝聚乙烯亚胺（PEI）对好氧颗粒进行改性，以实现 Cr(VI) 的同时吸附和解毒。改性后，改性好氧颗粒（MAG）在 pH 5.5 时的吸附容量约为 401.5 mg/g，与对照相比增加了 274%。吸附实验作为接触时间、pH 和 Cr(VI)浓度的函数进行。结果发现，平衡吸附可以在 3 小时内达到，并且该过程符合 Redlich-Peterson 等温模型。吸附过程是溶液 pH 的函数，在 pH 5.2 时吸附效果更好。通过应用傅里叶变换红外光谱（FTIR）和 X 射线光电子能谱（XPS）分析阐明了 Cr 与 MAG 之间的相互作用特征。FTIR 结果表明，吸附剂中的 -NH2 基团参与了吸附过程。XPS 结果证实了在 pH 范围 1.5-8.5 内 MAG 表面存在 Cr(III)，表明在吸附过程中部分 Cr(VI)阴离子被还原为 Cr(III)。
