Preferential and Enhanced Adsorption Ability of ZrO2 Nanoparticles for the Removal of Cationic, Anionic and Azo Dyes: Isotherm and Kinetic Studies

Abstract

Adsorption of Coomassie Brilliant Blue R-250, Congo Red and Acridine Orange from aqueous solution has been examined using ZrO2 nanoparticles, which proved to be a novel adsorbent. ZrO2 nanoparticles have been prepared by simple chemical precipitation method. The characterization of ZrO2 nanoparticles has been carried out by UV-vis spectroscopy, FTIR, XRD, TEM and FESEM. ZrO2 nanoparticles were found tetragonal in structure, spherical in morphology, and illustrated constricted size window (8–12 nm). The findings depicted that adsorbate removal on ZrO2 nanoparticles was affected significantly by change in adsorbent dose, pH and initial dye concentration w.r.t to contact time. The isotherms were well elaborated using Langmuir and Freundlich adsorption isotherms. The adsorptive kinetics was also investigated with pseudo-second-order to evaluate constant corresponding to rate. Moreover, the ZrO2 nanoparticles along with adsorbed dyes were desorbed. The identities of recovered nanoparticles as well as the adsorbed dyes were found to be same.