Use of experimental design to evaluate the adsorption of chromium (VI) by alginate/polyaniline beads

Low-cost decorated sodium alginate beads with polyaniline (Alg@PANI beads) were easily prepared using a cross-linking method, and employed for the adsorption of Cr(VI) from aqueous solutions. The effect of several influencing parameters, including temperature, contact time, Cr(VI) concentration, and adsorbent dosage, was investigated and optimized using central composite design (CCD) under response surface methodology (RSM). The analysis of variance (ANOVA) of the quadratic model and the analyzed model revealed that the models were statistically significant, with a low P-value (<0.0001) and a high correlation coefficient value (R-2 = 0.93). The optimum parameters for total adsorption were as follows: adsorbent dose 0.027 g, pH 2, contact time 45 min, temperature 38 degrees C, and Cr(VI) concentration 29.24 ppm. The findings of this study indicate that the prepared Alg@PANI beads could be effectively used to remove Cr(VI) ions from aqueous solutions.