海藻酸钠/三元水滑石复合微球的制备及其吸附性能研究

Preparation of sodium alginate/ternary hydrotalcite composite microspheres and their adsorption properties

采用水热法将十二烷基苯磺酸钠(SDBS)修饰到煅烧的MnMgFe三元水滑石上,结合海藻酸钠(SA)阳离子形成新型复合微球(SA@MFMc-S),用于吸附亚甲基蓝。该策略具有绿色环保、易回收利用、受pH值和温度影响较小的优点。利用单因素变量实验对反应条件进行优化,并拟合吸附动力学、热力学模型,初步分析了材料的吸附机理。结果表明:最佳实验条件为303 K、pH=8、固液比为0.33 g·L^(-1)、反应时间为360 min。吸附过程符合Langmuir吸附等温线,最大吸附容量为743.86 mg·g^(-1),是自发的放热反应,吸附动力学可用伪二级动力学方程描述。经SEM-EDS、BET、XRD、FTIR方法表征吸附前后的微球,发现主要参与吸附反应的官能团是羧基和羟基,同时存在苯环之间的π-π键作用力。这项研究成果为高浓度亚甲基蓝废水处理提供了一种高去除率和高吸附容量的绿色方法。

Calcined MnMgFe ternary hydrotalcite was modified with sodium dodecyl benzene sulfonate(SDBS)using a hydrothermal method.This was combined with sodium alginate(SA)cations to create a novel composite microsphere(SA@MFMc-S)for the purpose of adsorbing methylene blue.The resulting material has several advantages,including being environmentally friendly,easy to recycle,and insensitive to changes in pH and temperature.The reaction conditions were optimized through a single-factor experiment.Adsorption kinetics and thermodynamic models were used to analyze the adsorption mechanism.The results showed that the optimal experimental conditions were 303 K,pH of8,a solid-liquidratioof 0.33 g·L^(-1),and a reaction time of 360 minutes.The adsorption process followed the Langmuir isotherm,with a maximum adsorption capacity of 743.86 mg g,indicating a spontaneous and exothermic reaction.The adsorption kinetics were described by a pseudo-second-order kinetic equation.The microspheres were characterized before and after adsorption using SEM-EDS,BET,XRD,FTIR methods,revealing that carboxyl and hydroxyl groups were the main functional groups involved in the adsorption reaction.In addition,this study observed r-interactions between benzene rings.The results demonstrate an effective method for treating high-concentration methylene blue wastewater,with high removal efficiency and adsorption capacity.