KOH activated cattail-leaf-based carbon as an effective adsorbent for removal of methylene blue from aqueous solutions

Abstract

In this paper, activated carbon was prepared from cattail leaves (C-AC) by two-step procedures using KOH as the activation agent. The structure and morphology of C-AC were characterized by scanning electron microscopy, nitrogen adsorption and X-ray diffraction. C-AC that was highly porous and had a high specific surface area (1546.56 m 2 ·g –1 ) were obtained under activation at 750°C for 40 min, which the adsorption process and equilibrium of methylene blue closely obeyed the pseudo-second-order kinetic model and Langmuir isotherm. The adsorption capacity reached 498.95 mg·g –1 with 15 mg adsorbent in 100 mg·L –1 for 30 min at 303.15 K. The adsorption was endothermic, spontaneous, and a physically controlled process. This work provides a potential adsorbent from cattail leaves for purification of wastewater containing dyes.