含氨基磁性微球的制备及其对酸性橙7的吸附性能

摘要

Magnetic microbeads (MM)were synthesized by suspension polymerization and then reacted with eth-ylenediamine to yield magnetic microbeads with amino groups (MM-EDA).The final product was characterized by scanning electron microscope (SEM),BET surface area,Fourier transform infrared spectrometer (FT-IR), and vibrating sample magnetometer (VSM).MM-EDA were used to adsorb acid orange 7 (AO7)from aqueous solution.Effect of initial concentration,pH,coexisting ions and contact time on adsorption amount of AO7 was investigated.The experimental results indicated the highest adsorption capacity of AO7 was around pH=3.At room temperature,the adsorption of AO7 on MM-EDA reached equilibrium within 120 min and saturated ad-sorption capacity for AO7 was approximately 300 mg/g.The adsorption isotherm can be well described by the Langmuir equation and the adsorption kinetics fitted to the pseudo-second-order model.The thermodynamic pa-rameters (ΔG°,ΔH°and ΔS°)indicated that the adsorption was spontaneous and endothermic process with in-creased entropy,and higher temperature would benefit the adsorption.The adsorbent can be repeatedly utilized with no significant loss of adsorption capacity.%采用悬浮聚合法制备了磁性微球(MM)，利用乙二胺与磁性微球进行开环反应得到表面含有氨基的磁性微球(MM-EDA)。通过扫描电镜(SEM)、BET比表面积、傅里叶红外光谱(FT-IR)和样品磁力振荡计(VSM)进行了表征，并将其应用于对染料酸性橙7(AO7)的吸附。探索了初始浓度、吸附时间、pH 值和共存离子等条件对吸附的影响，研究了 MM-EDA 对AO7的吸附性能与吸附机理。结果表明，在 pH 值＝3左右溶液中，吸附量最大。在室温下，吸附在120 min内达到饱和，且对 AO7的饱和吸附量接近300 mg/g。吸附规律较好地符合准二阶动力学吸附方程和 Langmuir 等温吸附模型；热力学参数(ΔG°，ΔH°和ΔS°)说明吸附为自发、吸热的熵增加过程，升温有利于吸附；MM-EDA 可重复使用。