Department of Chemical and Materials Engineering, National I-Lan University, I-Lan 260, Taiwan.
J Hazard Mater. 2011 Jan 30;185(2-3):1124-30. doi: 10.1016/j.jhazmat.2010.10.022. Epub 2010 Oct 14.
A magnetic adsorbent, amine-functionalized silica magnetite (NH(2)/SiO(2)/Fe(3)O(4)), has been synthesized to behave as an anionic or cationic adsorbent by adjusting the pH value of the aqueous solution to make amino groups protonic or neutral. NH(2)/SiO(2)/Fe(3)O(4) were used to adsorb copper ions (metal cation) and Reactive Black 5 (RB5, anionic dye) in an aqueous solution in a batch system, and the maximum adsorption were found to occur at pH 5.5 and 3.0, respectively. The adsorption equilibrium data were all fitted the Langmuir isotherm equation reasonably well, with a maximum adsorption capacity of 10.41 mg g(-1) for copper ions and of 217 m g g(-1) for RB5. A pseudo-second-order model also could best describe the adsorption kinetics, and the derived activation energy for copper ions and RB5 were 26.92 kJ mol(-1) and 12.06 kJ mol(-1), respectively. The optimum conditions to desorb cationic and anionic adsorbates from NH(2)/SiO(2)/Fe(3)O(4) were provided by a solution with 0.1M HNO(3) for copper ions and with 0.05 M NaOH for RB5.
一种磁性吸附剂，即胺功能化硅磁铁矿（NH2/SiO2/Fe3O4），可以通过调节水溶液的 pH 值来调整为质子化或中性的氨基，从而表现为阴离子或阳离子吸附剂。NH2/SiO2/Fe3O4在批处理系统中被用于吸附水溶液中的铜离子（金属阳离子）和活性黑 5（阴离子染料），发现最大吸附分别发生在 pH 值为 5.5 和 3.0 时。吸附平衡数据均很好地符合朗缪尔等温线方程，铜离子的最大吸附容量为 10.41mg/g，活性黑 5 的最大吸附容量为 217mg/g。拟二级动力学模型也能很好地描述吸附动力学，铜离子和活性黑 5 的吸附活化能分别为 26.92kJ/mol 和 12.06kJ/mol。用 0.1M HNO3溶液可将阳离子吸附剂从 NH2/SiO2/Fe3O4上解吸，用 0.05M NaOH 溶液可将阴离子吸附剂从 NH2/SiO2/Fe3O4上解吸。
