响应面法优化磁性氧化石墨烯吸附亚甲基蓝及其动力学研究

Optimization by response surface method for adsorption of methylene blue in aquatic solution with magnetic graphene oxide and its kinetics

采用超声-沉淀法制备磁性氧化石墨烯(MGO)复合材料。通过傅里叶红外光谱仪FTIR和场发射扫描电子显微镜FESEM对MGO进行表征。采用响应面优化实验设计对MGO吸附亚甲基蓝(MB)的工艺过程进行了优化,设定Fe3O4质量浓度、氧化石墨烯(GO)质量浓度、吸附温度和MB初始质量浓度为4个因素,MB吸附率为响应值,建立了吸附率与上述因素之间的二次多项式模型,确定最佳吸附条件,并进行动力学方程和吸附等温线拟合。结果表明,Fe3O4用量和MB初始质量浓度是显著因素,MB的最佳吸附条件为:Fe3O4质量浓度4.08 g/L、GO质量浓度4.76 g/L、温度40℃、MB初始质量浓度18.5 mg/L,此时吸附率可达99.09%。吸附符合Langmuir等温线方程。MGO呈褶皱片层结构,含有羧基、羰基、羟基和环氧基等活性基团,是一种用于处理染料废水的高效、绿色吸附剂。

Magnetic graphene oxide(MGO)composites were prepared by ultrasonic-precipitation method.MGO was characterized by FTIR and FESEM.Response surface method was used to optimize the adsorption process of methylene blue(MB)on MGO.Four factors,including Fe3O4 dosage,GO dosage,adsorption temperature and initial concentration of MB were employed to study the adsorption rate of MB from aqueous solution by MGO.The adsorption rate of MB was the response value.A quadratic model about the adsorption rate associated with above factors was derived,through which the optimum adsorption conditions was gained.The kinetic equations and adsorption isotherms were fitted.The results showed that the dosage of Fe3O4 and the initial concentration of MB were significant factors.The adsorption rate reached 99.09%at the optimized conditions of nano-Fe3O4 4.08 g/L,graphene oxide 4.76 g/L,adsorption temperature 40℃,the initial concentration of MB 18.5 mg/L.The adsorption performance was well fitted with the Langmuir isotherm model.MGO was folded lamellar structure containing carboxyl,carbonyl,hydroxyl and epoxy groups.It is an efficient and green adsorbent for dye wastewater treatment.