茶叶基多孔炭的制备及对甲基橙吸附的研究

Preparation and adsorption study of waste tea-based porous carbon for methyl orange dyes

为减少废弃茶叶对环境的污染以及增加其高附加值,以废弃茶叶为碳源,采用化学活化法制备出茶叶基多孔炭。利用扫描电子显微镜、X射线衍射仪和氮气等温吸附对所得多孔炭进行表征,研究了其对甲基橙(MO)废水的吸附性能并分析了多孔炭对MO的等温吸附模型和动力学模型。结果表明,制备出的茶叶基多孔炭具有丰富的孔隙结构,其中NaOH作为活化剂制备的多孔炭HPC-NaOH比表面积达到3026 m^(2)/g,其中微孔面积为2811 m^(2)/g,总孔体积为1.54 m^(3)/g。当MO初始质量浓度为200 mg/L,HPC-NaOH投加量为1.5 g/L时,HPC-NaOH的最大吸附量为1264.66 mg/g,MO去除率高达94.85%。多孔炭HPC-NaOH对MO的吸附过程符合Langmuir吸附等温模型和准二级动力学模型,表明吸附过程属于单分子化学吸附类型。

In order to reduce the environment pollution caused by waste tea and increase its high added value.In this paper,waste tea was used as raw material and waste tea-based porous carbon was prepared by chemical activa⁃tion with waste tea as raw material.The tea-based porous carbon were characterized by scanning electron micro⁃scope,X-ray diffraction and nitrogen adsorption/desorption.The adsorption performance of methyl orange(MO)in wastewater was studied and the isothermal adsorption model and kinetic model of tea-based porous carbon on MO were further analyzed.The results showed that the tea-based porous carbon had rich pore structure and the specific surface area of porous carbon HPC-NaOH reached 3026 m^(2)/g with a microporous surface area of 2811 m^(2)/g and the total pore volume of 1.54 m^(3)/g.With the initial concentration of MO of 200 mg/L and a dosage of 1.5 g/L,the maxi⁃mum adsorption capacity of porous carbon HPC-NaOH was 1264.66 mg/g and the removal rate of MO was as high as 94.85%.the adsorption process of porous carbon HPC-NaOH for MO was conformed to Langmuir model and the pseudo-second-order kinetic equation,indicating that the adsorption process belonged to the chemical adsorption of a single molecular layer.