Application of Taguchi method for optimization of process parameters in adsorption of methylene blue by nanocomposite hydrogel adsorbents

Utilization of new methods for removal of chemical substance, such as dyes, from the outlet wastewater of different factories outlet is an important issue. In recent years, various methods have been utilized including the polymeric hydrogels for removal of dyes and heavy metals from aqueous solutions. In this work, nanocomposite hydrogel adsorbents on the basis of poly vinyl alcohol containing 0, 4, 8 and 12 wt.% (based on dry basis) of montmorillonite were prepared using a cyclic freezing-thawing process. The capabilities of the adsorbents for adsorption of a cationic dye, methylene blue, were studied in aqueous solutions having different temperatures, pH and solution concentrations. The Taguchi method was utilized to optimize the controllable factors, including the montmorillonite loading level, the solution temperature and pH and the methylene blue concentration in adsorption solution. Based on the Taguchi method, the percentage contribution of each parameter on the removal of methylene blue was determined using the Analysis of Variance (ANOVA) method and the following order was found: temperature of solution > concentration of methylene blue in solution > montmorillonite loading level in adsorbent > pH of solution. In general, the results indicated that the prepared nanocomposite hydrogel adsorbents are suitable materials for adsorption of cationic dyes and they can be used in practical applications.

Keywords:

Nanocomposite hydrogel , Adsorption , Taguchi method , Poly- (vinyl alcohol) , Montmorillonite , Methylene blue