Equilibrium adsorption studies on removal of diclofenac sodium from aqueous solution using sawdust-polyaniline (SD-PAn) composites

摘要

In this work, equilibrium adsorption studies were carried out for the removal of antiinflamatory drug diclofenac sodium (DS) from aqueous solutions using sawdust-polyaniline(SD-PAn) composite as a potential sorbent at 20, 30, and 40°C. The composite sorbent was characterized by FTIR and SEM analysis. The particles exhibited porous and rough surface. The equilibrium uptake data was interpreted by the Langmuir, the Freundlic, the Temkin, and the Dubinin-Redushkevich (D-R) isotherm models. The maximum adsorption capacity was found to decrease with increase in temperature, thus indicating exothermic nature of the adsorption process. The thermodynamic parameters were evaluated using Langmuir, Flory-Huggins, Frumkin, and modified-Frumkin models. The negative values of ΔG _(ads) ~0 and ΔH ~0 indicated spontaneous and exothermic nature of the adsorption process, respectively.