Removal of chromium ions by a bionanocomposite hydrogel based on starch-g-poly(acrylic acid) reinforced by cellulose nanofibers through a fix-bed adsorption column

A cellulose nanofibers reinforced starch-graft-poly(acrylic acid) (St-g-P(AA)) nanocomposite hydrogel was developed as a bio adsorbent to remove chromium ions [Cr(VI)] using a fix-bed adsorption column (FBC). The influence of several factors on adsorption column efficiency was investigated in this study, including pH, starting concentration of Cr(VI) ions, and solution input flow rate. Following the first study, the appropriate pH, starting concentration, and flow rate ranges were determined to be 4-6, 20-60 mg/L, and 5-15 mL/min, respectively. The surface response approach based on the Box-Behnken model was used to statistically examine the influence of each independent parameter on response performance (removal efficiency) and anticipate the optimal result. The findings showed that the pH of the solution had the most significant impact. The maximum removal efficiency of the nanocomposite hydrogel was 50.26 percent at pH = 6, an initial concentration of 20 mg/L, and a flow velocity of 10 mL/min. The Langmuir isotherm model successfully matched the results, and the maximum adsorption capacity was calculated to be 23.47 mg/g.