Évaluation de la capacité d’adsorption du naphtalène sur une mousse de tannin

The aim of the present study was to synthesize a tannin foam from white spruce bark and to evaluate its capacity to adsorb naphthalene, a polycyclic aromatic hydrocarbon which is very often found in contaminated soils and groundwater underlying these contaminated soils. The adsorption tests were carried out in batch mode. Adsorption process of naphthalene reached equilibrium after 1 hour of contact and was well described by Freundlich and Langmuir isotherms, with a slight advantage for the Langmuir model. Maximum adsorption capacity of naphthalene was determined (qm= 12.77 mg/g) and pseudo second order model described very well the process. The reaction rate constant for naphthalene removal was k2 = 0.036 g/mg.min. The relatively low enthalpy value (ΔadH0< 200 kJ/mol) indicated that during adsorption process, very low interactions occurred between naphthalene and tannin foam, such as Van Der Waals attraction or electrostatic strengths.