科研之友
微信
新浪微博
Facebook
分享链接
摘要
The adsorptive removal of cationic Methylene Blue and anionic Alizarin Red S was analysed in microcolumn tests. A detailed analysis of the influence of adsorbent surface acidity/basicity, elemental composition, Brunauer-Emmett-Teller area, pore distribution, and point-of-zero-charge pH on breakthrough properties was carried out. The characteristics of the mass transfer zone were used for evaluation of column performance. Four different activated carbons with different physical and chemical properties were analysed. It was concluded that, for adsorbents containing pores smaller than 1.7 times the solute molecular radius, the interactions between surface and solute have the greatest influence on the effective usage of column uptake capacity. A column packed with adsorbent characterised by large enough pores readily removed either anionic or cationic solutes. Partial correlation analysis revealed that the adsorption of cationic dye (Methylene Blue) was more sensitive to adsorbent textural properties in comparison with anionic dye (Alizarin Red S). Maximum column capacities were 3-4 times higher for cationic Methylene Blue than for anionic Alizarin Red S, with values of 494 and 107mg/g respectively. The higher solubility of Alizarin Red S could be responsible for its lower and more even removal efficiencies. Finally, the surface chemistry of the adsorbent affected how the operating conditions influenced the column performance, as deduced from the opposite effect of flow rate on the adsorption of Methylene Blue by each adsorbent.
- 出版日期2014-2
