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

Abstract

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 activation with waste tea as raw material. The tea-based porous carbon were characterized by scanning electron microscope, 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 3 026 m2/g with a microporous surface area of 2 811 m2/g and the total pore volume of 1.54 m3/g. With the initial concentration of MO of 200 mg/L and a dosage of 1.5 g/L, the maximum adsorption capacity of porous carbon HPC-NaOH was 1 264.66 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.

Keywords

• waste tea-based porous carbon
• methyl orange
• adsorption
• dynamics