Development of graphene oxide‐incorporated biopolymer‐carboxymethyl tamarind kernel gum‐based hydrogel as an effective adsorbent for the sequestration of dye pollutants

Abstract The present study describes the facile synthesis of graphene oxide (GO) and GO/carboxymethyl tamarind kernel gum (CMTKG)‐based hydrogel composite. The synthesized GO/CMTKG/PAM hydrogel composite was applied as an adsorbent for the selective sequestration of toxic crystal violet (CV) and methylene blue (MB) from an aqueous medium. The impact of various controlling parameters such as contact time, pH, concentration, adsorbent dosage, and temperature was studied. The experimental data obtained from the isotherm and kinetics modeling showed a good correlation with the Langmuir isotherm and pseudo‐second‐order kinetics model, respectively. The optimized concentration of dye was 40 mg L −1 for CV and 20 mg L −1 for MB, and the adsorption capacity (q max ) was calculated to be 111 mg g −1 for CV dye and 25 mg g −1 for MB dye. The synthesized adsorbent exhibits excellent recyclability for dye uptake after six consecutive cycles. Furthermore, the simultaneous adsorption of CV and MB from the binary system was carried out to ascertain the utility of the adsorbent in a wide range of adsorption systems. The adsorbent was also found to act as a proficient adsorbent in various water samples. These results demonstrated that synthesized hydrogel can be successfully applied as an adsorbent for the sequestration of dye effluents in real‐time applications. Highlights Hydrogel composite was successfully synthesized via a free radical mechanism. It is an efficient adsorbent for removing cationic dyes from aqueous solutions. It shows selectivity towards cationic dyes and works in a binary mixture of cationic dyes. It shows good removal efficacy in different water samples, including real wastewater samples. It also shows proficient removal efficacy after six consecutive regeneration cycles.