Application of the response surface methodology for optimizing the adsorptive removal of chromate using a magnetic crosslinked chitosan nanocomposite

Abstract

Experimental design was used to optimize the adsorptive removal of chromate using a synthesized crosslinked chitosan with a magnetic NiFe2O4 core. In this regard, the response surface methodology which is based on central composite design, was used to determine the relation between the parameters influencing the adsorption efficiency. The statistical parameters of the resulting model were R2 = 0.9922, and F‐value = 164.48. As a final step, a nonlinear optimization was performed and the respective optimal values for pH, amount of the adsorbent, initial concentration of the pollutant, and contact time were determined as 4, 0.8 g L−1, 150 ppm, and 25 min, and the predicted removal efficiency at a 95% confidence level was determined as 100.8 ± 1.8%, which was in good agreement with the experimental value (i.e., 95.5 ± 5.7%).