桉树遗态Fe/C复合材料对水中Cr(Ⅵ)的动态吸附探讨

为研究桉树遗态Fe/C复合材料（PBGC-Fe/C）对水中Cr（Ⅵ）的净化能力及其动态吸附过程，以PBGC-Fe/C吸附剂为固定床，选择溶液初始pH、进水流速、溶液初始浓度、吸附剂投加量和环境温度为影响因素开展动态吸附试验分析.结果表明:在溶液初始pH为2，进水流速为5.14 mL/min，吸附剂投加量为2 g和环境温度为35℃的条件下，PBGC-Fe/C对水中Cr（Ⅵ）的最佳平衡吸附容量达到10.72 mg/g；提高溶液初始pH、进水流速和溶液初始质量浓度或降低吸附剂投加量均可缩短反应穿透时间和衰竭时间；Thomas和Yoon-Nelson模型均能较好地描述PBGC-Fe/C对水中Cr（Ⅵ）的动态吸附过程，说明该吸附过程中内部扩散和外部扩散均为非限速步骤，吸附速率常数（k_Th）随着进水流速的增大从1.3×10-3 mL/（min·mg）升至2.6×10-3 mL/（min·mg），随着溶液初始质量浓度的增大从2.7×10-3 mL/（min·mg）降至1.4×10-3 mL/（min·mg）.研究显示，PBGC-Fe/C对水中Cr（Ⅵ）具有较好的动态吸附能力，具有较好的市场应用前景. 

Column Adsorption of Cr(VI) from Aqueous Solution by the Porous Biomorph-Genetic Fe/C Composite with Eucalyptus Wood Microstructure

The column adsorption of Cr(Ⅵ) from aqueous solution by the porous biomorph-genetic Fe/C composite prepared with eucalyptus template (PBGC-Fe/C) was experimentally studied. The effects of influent pH, influent flow rate, influent concentration, adsorbent dosage and temperature were examined to investigate the adsorption capacity and mechanism. The results indicated that the PBGC-Fe/C reached the maximum adsorption capacity for Cr(Ⅵ) of 10.72 mg/g under the operating conditions of the flow rate of 5.14 mL/min, the adsorbent dosage of 2 g and the temperature of 35℃ at pH=2.0. The increase in the influent pH, flow rate and Cr(Ⅵ) concentration or the decrease in the adsorbent dosage resulted in an earlier exhaustion and breakthrough of the PBGC-Fe/C column. The column adsorption breakthrough curves could be well fitted with the Thomas and the Yoon-Nelson models, indicating that the adsorption was not limited by the internal and external diffusion. The adsorption rate constant (k_Th) increased from 1.3×10-3 mL/(min·mg) to 2.6×10-3 mL/(min·mg) with the increase in the influent flow rate and decreased from 2.7×10-3 mL/(min·mg) to 1.4×10-3 mL/(min·mg) with the increase in the initial concentration. Consequently, the PBGC-Fe/C with a large capacity for the column adsorption of Cr(Ⅵ) from aqueous solution showed a broad application prospect.