三聚氰胺修饰的磁性O-羧甲基壳聚糖对锌(Ⅱ)的吸附性能

以环氧氯丙烷和O-羧甲基壳聚糖为原料,制备环氧化O-羧甲基壳聚糖(OCMC)后,再与Fe₃O₄和三聚氰胺 (MA)复合,制得三聚氰胺修饰的磁性O-羧甲基壳聚糖吸附剂(MA-OCMC/Fe₃O₄)。通过傅里叶变换红外光谱(FT-IR)表征其结构与官能团,并考察不同条件对吸附Zn²⁺的影响,同时研究其吸附动力学与等温吸附模型的特征。结果表明,控制pH值为6.0,0.13 g MA-OCMC/Fe₃O₄在100 mL 100 mg/L ZnCl₂溶液中吸附60 min后达到平衡,吸附行为符合拟二级动力学模型与Langmuir等温吸附模型特征,属于单分子层化学吸附,理论饱和吸附量(86.96 mg/g)接近实际饱和吸附量(86.48 mg/g)。在循环吸附-解吸6次后,MA-OCMC/Fe₃O₄对Zn²⁺的吸附率仅降低5.2%,具有良好的重复利用性,适用于含Zn²⁺废水的处理。

Adsorption performance of magnetic O-carboxymethyl chitosan modified by melamine for zinc(Ⅱ)

The epoxy chloropropane and O-carboxymethyl chitosan were used as raw material to synthesize epoxide O-carboxymethyl chitosan (OCMC), which was then composited with Fe₃O₄ and melamine (MA) to prepare the adsorbent of magnetic O-carboxymethyl chitosan (MA-OCMC/Fe₃O₄) modified by melamine. The chemical structure and functional groups were characterized by Fourier-transformed infrared spectroscopy (FT-IR). Moreover, the effect of different conditions on the adsorption of Zn²⁺ was discussed. The characteristics of its adsorption kinetics and adsorption isotherm model were also investigated. The results showed that the adsorption equilibrium was reached when the adsorption time was 60 min for 0.13 g of MA-OCMC/Fe₃O₄ in 100 mL of 100 mg/L ZnCl₂ solution at pH 6.0. The adsorption behavior conformed to the characteristics of pseudo second-order kinetic model and Langmuir isotherm adsorption model, which indicated that the adsorption process belonged to monolayer chemical adsorption. The theoretical saturated adsorption capacity was 86.96 mg/g, which closed to saturated adsorption capacity of 86.48 mg/g. The adsorption efficiency for Zn²⁺ by MA-OCMC/Fe₃O₄ merely decreased by 5.2% after cyclic adsorption-desorption for 6 times, indicating that it had good performance of reusability. The proposed method was suitable for the treatment of wastewater containing Zn²⁺.