Statistical analysis of expanded graphite-decorated cobalt ferrite as adsorbent for removal of Congo Red dye using response surface methodology

In this study, exfoliated graphene-decorated cobalt ferrite was fabricated and used as an adsorbent toward Congo Red dye. The relationship between the adsorption parameters and the dye removal from the aqueous solution was explored using response surface methodology. We found that the removal efficiency using the decorated adsorbent far surpassed that obtained using non-decorated ferrite materials. In addition, to achieve maximal removal efficiency against Congo Red dye (87.46%) using the as-synthesized adsorbent, experimental parameters should consist of initial dye concentration of 58.20 mg.L-1, contact time of 189 min and pH of 6.05. ANOVA analysis results indicate that the model is statistically significant because the high R-2 and low P-value. Validation experiments further confirm those results. (C) 2020 The Authors. Published by Elsevier Ltd.