Groundnut shell chemically treated with KOH to prepare inexpensive activated carbon: Methylene blue adsorption and equilibrium isotherm studies

Abstract

Groundnut shell activated carbon (GNSAC) is made from groundnut shells using potassium hydroxide (KOH) at 600 °C in a nitrogen atmosphere. The properties of the products were examined using FT-IR, XRD , SEM with EDS , and BET analysis. The activating temperature of 600 °C and the impregnation ratio of 1:1 were observed as optimum for achieving the highest surface area (412 m 2 /g). The adsorption efficiency of optimized GNSAC (1:1) was evaluated using a methylene blue (MB) dye solution. The effects of contact time, pH, adsorbent dose, and beginning dye concentration on the removal efficiency of MB were investigated among the GNS/KOH ratios of a 1:1 sample used as the adsorbent. Additionally, the Langmuir and Freundlich adsorption models were used to support the adsorption isotherms . According to the adsorption data at these ideal conditions, GNSAC is capable of absorbing 83.33 mg/g of dye at equilibrium as demonstrated by the Langmuir isotherm. This result demonstrates that GNSAC is a potentially useful material for wastewater treatment .