Microporous activated carbon developed from KOH activated biomass waste: surface mechanistic study of methylene blue dye adsorption

In this work, sugarcane bagasse waste (SBW) was used as a lignocellulosic precursor to develop a high surface area activated carbon (AC) by thermal treatment of the SBW impregnated with KOH. This sugarcane bagasse waste activated carbon (SBWAC) was characterized by means of crystallinity, porosity, surface morphology and functional groups availability. The SBWAC exhibited Type I isotherm which corresponds to microporosity with high specific surface area of 709.3 m(2)/g and 6.6 nm of mean pore diameter. Further application of SBWAC as an adsorbent for methylene blue (MB) dye removal demonstrated that the adsorption process closely followed the pseudo-second order kinetic and Freundlich isotherm models. On the other hand, thermodynamic study revealed the endothermic nature and spontaneity of MB dye adsorption on SBWAC with high acquired adsorption capacity (136.5 mg/g). The MB dye adsorption onto SBWAC possibly involved electrostatic interaction, H-bonding and pi-pi interaction. This work demonstrates SBW as a potential lignocellulosic precursor to produce high surface area AC that can potentially remove more cationic dyes from the aqueous environment.

Automated summary

In this study, sugarcane bagasse waste was used to develop high surface area activated carbon for methylene blue dye removal. The adsorption process followed pseudo-second order kinetic and Freundlich isotherm models, involving electrostatic interaction, H-bonding, and pi-pi interaction. The activated carbon showed high adsorption capacity for MB dye, indicating its potential for removing cationic dyes from aqueous environments.