Abstract
The present work demonstrates a comparative study on the synthesis of "Eucalyptus" sawdust-derived porous carbons by two distinct methods including thermal carbonization and thermochemical activation. The representative sample-PAC demonstrate a remarkable specific surface area (SSA similar to 2841 m(2) g(-1)), total pore volume (V-T similar to 1.2850 cm(3) g(-1)), well-developed pore-size distribution, ample amount of oxygen content (12.34 at. %), and amorphous nature with some pi-electron-rich graphitic domains. When used for MB adsorption experiment, PAC demonstrate a remarkable MB adsorption capacity of PAC (625 mg g(-1) at an initial concentration of 200 mg L-1) attributed to the primary role of hierarchical micro-mesoporosity with enough population of micropores of optimum pore size (similar to 1.5 nm) comparable to the kinetic diameter of MB (1.4 nm). Various parameters such as effect of morphology, effect of pH, regeneration/recyclability of spent adsorbent, and MB adsorption in real waste water were comprehensively studied. Additionally, adsorption kinetics and thermodynamics studies were also explored which indicate a kind of physical endothermic mechanism existing for the biomass-derived ACs. Moreover, the distinct types of interactions including electrostatic interactions, pi-pi interaction, and hydrogen linkage, generated between the oxygen-functionalized aromatic ring of sorbent surface and dye molecule, also facilitate the efficient MB adsorptive removal. Lastly, to demonstrate the practical application, an experiment comprising of a fixed bed of PAC on a continuous flow MB filtration unit results in a 98% removal of MB from wastewater which therefore highlights the potential of prepared material as an efficient sorbent for industrial wastewater remediation.