海藻酸钠微球的制备优化及其吸附模型

Optimization of Preparation of Sodium Alginate Microspheres and Its Adsorption Behavior Modeling

摘要:

为了得到能高效脱色染料的吸附剂，以海藻酸钠、聚乙烯醇和沸石为原料，在单因素实验的基础上，采用Box-Behnken实验设计原理进行三因素三水平的响应面实验设计，以脱色率为响应值，选取海藻酸钠（SA）、聚乙烯醇（PVA）和沸石质量浓度作为影响因子，优化其最佳制备条件。结果表明SPZ最佳制备条件为：SA质量浓度11 g/L，PVA质量浓度21 g/L，沸石质量浓度52 g/L，所得实际脱色率为88.57%。扫描电子显微镜观察到亚甲基蓝（MB）被成功吸附在海藻酸钠凝胶微球（SPZ）表面，傅里叶红外光谱结果说明SPZ与MB之间存在氢键及静电相互作用，且吸附过程符合准二级动力学、Langmuir型等温吸附模型，其吸附过程为物理扩散并伴随着化学吸附。本研究证明SPZ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参考。

Abstract:

To obtain an adsorbent with high efficiency for the decolorization of dyes, sodium alginate, polyvinyl alcohol and zeolite are used as adsorption materials. Based on the results of the single factor experiment, Box-Behnken experimental design is adopted to conduct a three-factor and three-level response surface test. Decolorization rate is taken as the response; sodium alginate (SA), polyvinyl alcohol (PVA) and zeolite concentration are selected as the influencing factors to optimize the preparation conditions. The results show that the optimum preparation conditions of SPZ are: SA 11 g/L, PVA 21 g/L, zeolite 52 g/L, and the actual decolorization rate is 88.57%. SEM result shows that methylene blue (MB) is successfully adsorbed on SPZ surface. FTIR result shows that there are hydrogen bonds and electrostatic interactions between SPZ and MB. The adsorption process follows the quasi-second-order kinetics and fitts Langmuir isothermal adsorption model, which indicates that the adsorption process can be described as physical diffusion accompanied by chemical adsorption. The results indicate that the SPZ adsorbent has good stability and high decolorization rate. This study will offer references to the application of sodium alginate composite material in the treatment of dye wastewater.