Low-cost preparation of silica aerogel for optimized adsorptive removal of naphthalene from aqueous solution with central composite design (CCD)

Abstract

Nanostructured silica aerogels are expensive porous materials with unique properties. Thus, the application of a cost-effective synthesis method will be highly effective for large-scale. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), BET surface area and contact angle and the density was determined by the pycnometry method. To investigate the adsorptive performance of silica aerogel, naphthalene pollutant was used as an organic pollutant model in the wastewater. In this study the process variables such as contact time, concentration of adsorbent, pH of solution and interaction of these variables in the adsorption process for the removal of the naphthalene from water by silica aerogel were evaluated. Furthermore, to achieve the predicted model and prepare the optimum condition of the process, the central composite design of the response surface methodology was utilized. According to the results of ANOVA table, a second order nonlinear model was obtained to predict the removal of naphthalene. The model adequacy was guaranteed by the assessment of statistical parameters such as coefficient of determination (R2=0.903), adjusted R2 (0.877) and adequate precision (19.23). In the kinetic study, the pseudo-second order model was consistent with the experimental results.