Wang Yixi, Zhao Linyan, Hou Juan, Peng Huili, Wu Jianning, Liu Zhiyong, Guo Xuhong
School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, Xinjiang 832003, China E-mail:
Water Sci Technol. 2018 Jun;77(11-12):2699-2708. doi: 10.2166/wst.2018.229.
In this study, a highly efficient and eco-friendly porous cellulose-based aerogel was synthesized by grafting polyethyleneimine onto quaternized cellulose (PQC) to remove the anionic dye Congo Red (CR). The prepared aerogel had a good flexibility and formability. The adsorbents were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and elemental analysis. The results showed that there were many amino groups on CE/PQC aerogel and the structure was porous, which increased the adsorption capacity. The effects of initial concentration, adsorbent dose, contact time, temperature, and pH on the dye sorption were all investigated. The adsorption mechanism was also explored, including adsorption kinetics, adsorption isotherms and thermodynamic studies of adsorption. The results showed that the adsorption kinetics and isotherms fitted the pseudo-second-order kinetic model and Langmuir isotherm, respectively. The Langmuir isotherm revealed that the maximum theoretical adsorption capacity of the aerogels for CR was 518.403 mg g. The thermodynamic parameters including Gibbs free energy change (ΔG), enthalpy change (ΔH) and entropy change (ΔS), showed the adsorption process was exothermic and spontaneous. These results imply that this new absorbent can be universally and effectively used for the removal of dyes from industrial textile wastewater.
在本研究中，通过将聚乙烯亚胺接枝到季铵化纤维素（PQC）上合成了一种高效且环保的多孔纤维素基气凝胶，用于去除阴离子染料刚果红（CR）。制备的气凝胶具有良好的柔韧性和可成型性。通过扫描电子显微镜（SEM）、傅里叶变换红外（FTIR）光谱和元素分析对吸附剂进行了表征。结果表明，CE/PQC气凝胶上有许多氨基且结构多孔，这提高了吸附容量。研究了初始浓度、吸附剂剂量、接触时间、温度和pH对染料吸附的影响。还探讨了吸附机理，包括吸附动力学、吸附等温线和吸附热力学研究。结果表明，吸附动力学和等温线分别符合准二级动力学模型和朗缪尔等温线。朗缪尔等温线表明，气凝胶对CR的最大理论吸附容量为518.403 mg/g。包括吉布斯自由能变化（ΔG）、焓变（ΔH）和熵变（ΔS）在内的热力学参数表明吸附过程是放热且自发的。这些结果表明，这种新型吸附剂可普遍有效地用于去除工业纺织废水中的染料。
