Adsorption of ammonia on activated carbon from aqueous solutions

Abstract

AbstractIn this study, adsorption of ammonia on activated carbon from aqueous solutions has been studied in a batch stirred cell. Experiments have been carried out to investigate the effects of temperature, ammonia concentration, and activated carbon dose on ammonia adsorption. The experimental results manifest that the ammonia adsorption rate on activated carbon increases with its concentration in the aqueous solutions. Ammonia adsorption also increases with temperature. The ammonia removal from the solution increases as activated carbon mass increases. The Langmuir and Freundlich equilibrium isotherm models are found to provide a good fitting of the adsorption data, with r2 = 0.9749 and 0.9846, respectively. The adsorption capacity of ammonia obtained from the Langmuir equilibrium isotherm model is found to be 17.19 mg g−1. The kinetic study shows that ammonia adsorption on the activated carbon is in good compliance with the pseudo‐second‐order kinetic model. The thermodynamic parameters (▵G°, ▵H°, ▵S°) obtained indicate the endothermic nature of ammonia adsorption on activated carbon. © 2008 American Institute of Chemical Engineers Environ Prog, 2008