Kinetics and equilibrium studies of the adsorption of methylene blue on Euryale ferox shell‐based activated carbon

Abstract

Euryale ferox shells were used to prepare activated carbon (AC) by physiochemical activation using potassium hydroxide as the activation agent at 800°C for 2 h. The as-prepared AC surface area was 2028 m2 g−1, while the average pore diameter and total pore volume were 3.425 nm and 0.98 cm3 g−1, respectively. The equilibrium and kinetics for the adsorption of methylene blue (MB) on E. ferox shell-based AC were investigated at 20°C. The equilibrium data for MB adsorption were in agreement with Langmuir equation, and the maximum adsorption value was 617 mg g−1. Adsorption was denoted by two simplified kinetic models, pseudo-first-order and pseudo-second-order equations, respectively. The MB adsorption was well fitted to the pseudo-second-order model. Thermodynamics parameters were calculated and discussed and the adsorption of MB on E. ferox shell-based AC was exothermic and spontaneous.