Isotherm and Thermodynamic Studies of the Biosorption of Humic Acid from Aqueous Solution by Pine Sawdust based Activated Charcoal

Abstract

Activated charcoal was prepared from pine tree sawdust by chemical activation by means of phosphoric acid (PSDP) that was used for Humic acid bio sorption from aqueous medium. The influence of humic acid initial concentration, sorbent mass, and solution temperature on sorption process was investigated. Langmuir and Freundlich isotherm models were used to analyze the equilibrium sorption data. The maximum adsorption capacities of PSDP obtained from Langmuir were 170.9, 182.1 and 209.6 mg/g at 25°C, 45°C and 65°C, respectively. Humic acid adsorption 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).