State Key Laboratory Breeding Base of Nuclear Resources and Environment, East China Institute of Technology, Nanchang, 330013, PR China.
J Hazard Mater. 2011 Jan 30;185(2-3):1045-52. doi: 10.1016/j.jhazmat.2010.10.012. Epub 2010 Oct 28.
The adsorption characteristics of Acid Orange 7(AO7) and Acid Orange 10 (AO10) from aqueous solutions onto the ethylenediamine-modified magnetic chitosan nanoparticles (EMCN) have been investigated. The EMCN were essentially monodispersed and had a main particle size distribution of 15-40 nm and saturated magnetization of 25.6 emu/g. The adsorption experiments indicated that the maximum adsorption capacity occurred at pH 4.0 for AO7 and pH 3.0 for AO10, respectively. Due to the small diameter and the high surface reactivity, the adsorption equilibrium of AO7 and AO10 onto the EMCN reached very quickly. Equilibrium experiments fitted well with the Langmuir isotherm model, and the maximum adsorption capacity of the EMCN at 298K was determined to be 3.47 mmol/g for AO7 and 2.25 mmol/g for AO10, respectively. Thermodynamic parameters such as enthalpy change (ΔH°), free energy change (ΔG°) and entropy change (ΔS°) were estimated and the results indicated that the adsorption process was spontaneous and exothermic. Furthermore, the EMCN could be regenerated through the desorption of the dyes in NH(4)OH/NH(4)Cl solution (pH 10.0) and could be reused to adsorb the dyes again.
从水溶液中用乙二胺修饰的磁性壳聚糖纳米粒子（EMCN）吸附酸性橙 7（AO7）和酸性橙 10（AO10）的吸附特性进行了研究。EMCN 基本呈单分散性，主要粒径分布为 15-40nm，饱和磁化强度为 25.6emu/g。吸附实验表明，AO7 的最大吸附容量出现在 pH4.0，AO10 的最大吸附容量出现在 pH3.0。由于直径小且表面反应性高，AO7 和 AO10 吸附到 EMCN 上的吸附平衡非常迅速。平衡实验很好地符合朗缪尔等温线模型，在 298K 下，EMCN 对 AO7 的最大吸附容量为 3.47mmol/g，对 AO10 的最大吸附容量为 2.25mmol/g。估计了热力学参数，如焓变（ΔH°）、自由能变（ΔG°）和熵变（ΔS°），结果表明吸附过程是自发的和放热的。此外，EMCN 可以通过在 NH（4）OH/NH（4）Cl 溶液（pH10.0）中解吸染料进行再生，并可再次用于吸附染料。
