Anshul’s research while affiliated with Dr. B. R. Ambedkar National Institute of Technology Jalandhar and other places

Chitosan- and Carboxymethyl cellulose-based hydrogel materials are synthesized by incorporating Bentonite and characterized with different characterization techniques like FTIR, FESEM, EDX and XRD. The most optimized conditions for getting maximum percentage swelling were 50 °C temperature, 25 ml of solvent, pH (9), 20 h of reaction time and 1:1 ratio of reactants (CMC/Chitosan), and 0.05 (mol/L) of Bentonite. The synthesized hydrogel materials are evaluated for the removal of toxic dyes like Rose Bengal and Malachite Green. Different kinetic models were used to measure the kinetic parameters, and different isotherm models were used to evaluate the type of adsorption take place on hydrogel materials. During Adsorption process, 91.75% of Rose Bengal and 96.09% of Malachite Green have been removed. The pseudo-second-order kinetic model has been found as the best fitted model for adsorption of dyes on the synthesized hydrogel. From adsorption isotherm studies, it was concluded that the Langmuir model was found to be the best fitted model and the adsorption was found to be homogenous and physical adsorption. The activation energy values for Rose Bengal and Malachite Green were found to 2.36 and 1.22 kJ/mol, respectively, at room temperature which further supports the adsorption is homogenous and by physical interaction means. The negative values of change in Gibbs free energy from 303 K temperature to 333 K temperature further confirmed the adsorption process is spontaneous for both the dyes. The synthesized hydrogel material was found to be an excellent adsorbent to remove these toxic dyes from the waste water and can be utilized as a green and sustainable material for waste water remediation. Graphical abstract