MODELING OF ADSORPTION' STUDIES OF PHENOL AND SALICYLIC ACID ON DUOLITE RESIN

Abstract

Phenolic compounds are undesirable pollutants in the environment, specifically in aquatic media. Salicylic acid is a phenolic compound, and together with phenol, which is its precursor, it is present in wastewaters from different industries. Adsorption being one of the most common ways for these wastewater treatment, a mathematical model to describe the adsorption phenomenon is developed. Langmuir Isotherm is taken as the basis to predict the equilibrium concentrations of the adsorbed and the solute phases. For modeling the adsorption kinetics, a linear driving force (LDF) approximation was used. The LDF rate constant accounting for macropore diffusion and adsorption and the film mass transfer resistance were grouped in an overall mass transfer coefficient. The model developed is solved by the PDEPE TOOLBOX of MATLAB 7.1.0. and the adsorption of phenol and salicylic acid onto Duolite resin is compared. The adsorptive capacity of the Duolite is more for phenol (96.13 mg/g) than that of salicylic acid (43.01 mg/g). The model well predicts this phenomenon, as the adsorption of phenol is more than that of the salicylic acid on the considered Duolite resin for the different runs carried out