Effective adsorption of Chromium (III) ions from the tannery effluent wastewater using Cerium Oxide (CeO2) nanoparticles

This investigation focuses on chromium (III) ions' efficient adsorption from wastewater tanning effluent by cerium oxide (CeO2) nanoparticles. The properties of cerium oxide (CeO2) nanoparticles were examined through the use of FTIR, XRD, EDX, TGA, TEM and SEM analyses. The present investigation sought to scrutinise various parameters, namely adsorbent dosage, temperature and pH of the solution. The Langmuir, Freundlich, Temkin and Harkins–Henderson isotherm models were employed, and the resulting coefficients were determined as 0.99, 0.80, 0.95 and 0.68, respectively. In comparison with other models, the Langmuir model was found to be more suitable for elucidating the adsorption process. The study also obtained results concerning kinetics, with the Pseudo-first-order exhibiting a value of 0.989, Pseudo-second order showing 0.947, Intraparticle diffusion generating 0.969 and Elovich model producing 0.905. As per the results, the Pseudo-first-order kinetic equation was determined as the most appropriate one for characterising the kinetics of the reaction. The experimental study shows that the synthesised adsorbent removed chromium (III) ions highly efficiently from the tannery effluent wastewater. After being regenerated with a basic eluent (NaOH), CeO2 nanoparticles can be employed for chromium adsorption at least twice with an efficiency retention of roughly 85% and 75%, respectively.