Desorption of phenol from Lantana camara, forest waste: Optimization using response surface methodology and kinetic studies

In the present work, desorption studies to recover the adsorbed phenol from HCl treated adsorbent were carried out with ethanol solution. The experimental conditions like ethanol concentration, desorption time and temperature were optimized using response surface methodology. From the central composite design, a quadratic model was developed to relate the process variables to the percentage desorption as the response. From the analysis of variance (ANOVA), the most significant factor on the response was determined. The predicted percentage desorption values from the model was in good agreement with the experimental values. Therefore to understand the mechanism involved in desorption of phenol, desorption kinetics were performed at optimum conditions. The modelling of desorption data were done using pore-diffusion and first-order kinetic model. The data followed first-order kinetic model better than the pore-diffusion model. The percentage desorption was found to be 82.1% showing that ethanol is effective in desorbing phenol from the adsorbent.