Adsorptive removal of chromium(VI) from aqueous solution using binary bio-polymeric beads made from bagasse

Abstract

Abstract In this study, bio-polymeric gel beads were made from synthetic and laboratory-made CMC (bagasse). Calcium chloride cross-linked with sodium alginate (Na-Alg) added to CMC displayed great affinity for the removal of hexavalent chromium (Cr(VI)) ions present in an aqueous solution. Activated carbon obtained from bagasse was also used for adsorptive removal of Cr(VI) ions from aqueous solution. The effect of different adsorption parameters such as pH, contact time and adsorbent dosage was studied. Bio-polymeric gel beads and activated carbon were prepared and characterized by SEM, FTIR and XRD. The maximum percentage removal for synthetic and bagasse bio-polymeric gel beads reaches 94.56% and 98.42% values at a pH of 4.0 at 25 °C and for activated carbon 64.79% value at a pH of 6.0 at 25 °C. Higher degree of substitution results in an increase in the percentage removal of Cr(VI) ions due to the increase in the surface area and the binding sites of the adsorbent. Our study suggests that bio-polymeric gel beads made from laboratory-made CMC (bagasse) can be used in a more cost-effective and efficient way for the removal of harmful chromium ions.

Keywords

• Carboxymethyl cellulose (CMC)
• Sodium alginate
• Gel beads
• Activated carbon