Brilliant Yellow dye adsorption onto sepiolite using a full factorial design

Batch adsorption experiments were carried out in order to evaluate the maximum adsorption conditions of the anionic dye Brilliant Yellow (BY) from aqueous solutions on sepiolite using a 23 full factorial design. The three factors were temperature, the initial pH of the solution, and the ionic strength of the dispersion. The optimization of the factors to obtain maximum adsorption was carried out by incorporating effect plots, normal probability plots, interaction plots, analysis of variance (ANOVA), Pareto charts, surface plots, and contour plots. The statistical design experiments, designed to reduce the total number of experiments required, indicated that, within the selected conditions, all the parameters influenced at a significance level of 5%. In addition, some of the possible interactions between these parameters also influenced the adsorption process, especially those that were of first order. A regression model was suggested and fitted the experimental data very well.

Research Highlights
► Batch adsorption experiments were carried out in order to evaluate the maximum adsorption conditions of the anionic dye Brilliant Yellow (BY) from aqueous solutions on sepiolite using a 23 full factorial design.
► The statistical design of the experiments combined with techniques of regression was applied in optimizing the conditions of maximum adsorption of the dye onto sepiolite.
► The initial pH of the dispersion exerted the greatest influence on the amounts of dye adsorbed Qe.