Isotherm and thermodynamic studies of the biosorption of Humic acid from aqueous solution by pine sawdust-based activated charcoal

Abstract

In this work, activated charcoal was prepared from pine tree sawdust by chemical activation using phosphoric acid (PSDP) that was applied for the biosorption of Humic acid from aqueous medium. The effect of sorbent mass, humic acid initial concentration and solution temperature on the adsorption process were investigated by batch experiments. The equilibrium sorption data were analyzed by Langmuir and Freundlich isotherm models. The maximum adsorption capacities of PSDP obtained from Langmuir were 170.9, 182.1 and 209.6 mg/g at 25^oC, 45^oC and 65^oC, respectively. The adsorption of humic acid onto PSDP was spontaneous, favorable at higher temperature and endothermic in nature. Activated charcoal from pine tree sawdust proves to have high capacity adsorptive to natural organic compound (humic acid).