Single and bicomponent anionic dyes adsorption equilibrium studies on magnolia-leaf-based porous carbons

Abstract

A new type of porous carbon is prepared by cost-effective pyrolysis carbonization and subsequent alkali activation of an easily available biomass, magnolia leaf (ML). The as-prepared ML porous carbons (MPCs) show high specific surface areas and suitable pore size distributions. Surface characterization of ML and MPC-1 were investigated by N₂ adsorption, FT-IR, SEM and TEM. Two anionic azo dyes were used, namely, orange II (OII) and methyl orange (MO), to simulate the textile effluent. Batch experiments of OII and MO in a single dye system (SDS) and a binary dye system (BDS) onto MPC-1 were investigated as a function of pH, contact time and species concentration. The adsorption process followed the Langmuir isotherm model with high coefficients of correlation (R² > 0.999). The pseudo-second order kinetic model fitted well to the experimental results. This study indicates that MPCs demonstrated superior OII and MO adsorption capabilities and could be employed as a low cost alternative to commercially available porous carbon for the removal of dyes from wastewater.