Preparation of Activated Carbon Derived from Waste Peanut Shells to Remove Dye from Water in a Batch System

Abstract

Majority of peanut shells are thrown away or incinerated, which give rise to wasting resources and potential contamination. In this study, activated carbon (AC) from waste peanut shells were prepared with pyrolysis and K₂CO₃ activation process. The obtained peanut shell activated carbon (PSAC) were used to remove methylene blue (MB) in water. The orthogonal experiment design method was adopted to find the most suitable activation process. The modeling of adsorption isotherm and kinetic were conducted to explore the removal mechanism. The characterization results revealed that PSAC had a mesoporous structure with BET surface area of 735.6 m²/g and average pore diameter of 3.120 nm. Based on MB removal efficiency, the orthogonal experiments revealed that the order of the significant factor for PSAC preparation was activation temperature > activation time > impregnation ratio. The optimal parameters for preparing PSAC were at activation temperature 700 °C, activation time 90 min, and impregnation ratio 3:1. The equilibrium adsorption was simulated well by Langmuir isotherms model and the maximum adsorptivity was 615.92 mg/g. The adsorption kinetics followed the pseudo-second order model, which suggested that chemisorption was involved during the adsorption. Reusing experiments indicated PSAC had satisfactory reusability and stability for MB removal.

Keywords:

• Peanut shell
• activated carbon
• chemical activation
• adsorption isotherms
• kinetics

Data Availability

The data used to support the findings of this study are available from the corresponding author upon request.

Additional information

Funding

This work was supported by Research Climbing Program of Xiamen University of Technology (XPDKQ19015).