KCl改性海藻酸钠微球的吸附性能

Adsorption Properties of KCl-modified Sodium Alginate Microspheres

目的为了提高海藻酸钠微球的吸附容量和脱色率。方法以海藻酸钠为原料,共混聚乙烯醇、沸石制备得到一种海藻酸钠微球,在此基础上进行KCl改性,制备得到海藻酸钠微球吸附剂KSPZ(KCl−SA−PVA−zeolite Microsphere)。通过单因素试验得到最佳吸附条件,对吸附前、后样品进行表征,并探究其吸附机理。结果得到KSPZ的最佳吸附条件,即pH值为9,吸附剂添加量为1 g/L,吸附时间为6 h,亚甲基蓝(Methylene blue,MB)的初始质量浓度为500 mg/L,此时吸附容量为426.63 mg/g,脱色率为85.33%。通过扫描电子显微镜观察到MB被成功吸附在KSPZ表面,其傅里叶红外光谱说明KSPZ与MB之间存在氢键和静电相互作用,且吸附过程符合准二级动力学、Langmuir型等温吸附模型,表明其吸附过程为物理扩散,并伴随着化学吸附。结论KSPZ是一种稳定性好、脱色率高的吸附剂,为海藻酸钠复合材料在染料废水处理中的应用提供了理论指导。

This paper aims to improve the adsorption capacity and decolorization rate of sodium alginate micro-spheres.Sodium alginate microspheres were prepared by blending polyvinyl alcohol and zeolite with sodium alginate as raw materials.On this basis,KSPZ(KCl-SA-PVA-zeolite microsphere)microspheres were modified by KCl.The optimal adsorption conditions were obtained by single factor test,and the samples were characterized before and after adsorption and the adsorption mechanism was explored.The results showed that the optimal adsorption conditions of KSPZ were as follows:pH 9,adsorption amount 1 g/L,adsorption time 6 h,initial mass concentration of MB(Methylene blue)500 mg/L,adsorption capacity 426.63 mg/g,decolorization rate 85.33%.SEM showed that MB was successfully adsorbed on SPZ surface.FTIR showed that there were hydrogen bonds and electrostatic interactions between KSPZ and MB.The ad-sorption process followed quasi-second-order kinetics and Langmuir isothermal adsorption model,which indicated that the adsorption process was physical diffusion accompanied by chemical adsorption.KSPZ is an adsorbent with good sta-bility and high decolorization rate,which provides guidance for the application of sodium alginate composite materials in the treatment of dye wastewater.