Supporting data from: Green-synthesized zeolite Y–supported zero-Valent iron nanocomposite for enhanced adsorptive reduction of hexavalent chromium from aqueous solutions

Hexavalent chromium (Cr(VI)), a major pollutant in tannery wastewater,
poses significant environmental and health risks. Zeolite Y possesses a
high cation-exchange capacity but low affinity for Cr(VI), which
predominantly exists in anionic forms in aqueous solutions. This study
aimed to modify Zeolite Y with zero-valent iron nanoparticles (nZVI) to
enhance its capacity to adsorb Cr(VI). The Zeolite Y/nZVI composite was
synthesized using green tea extract. nZVI effectively reduces Cr(VI) to
less toxic Cr(III), which precipitates as Cr(OH)₃. The composite was
characterized using X-ray diffraction (XRD), Fourier transform infrared
(FTIR) spectroscopy, scanning electron microscopy–energy dispersive X-ray
spectroscopy (SEM–EDX), particle size analysis (PSA), and pH point-zero
charge analysis. The highest Cr(VI) adsorption capacity was achieved under
acidic conditions (pH = 1), elevated temperature (343 K), an initial Cr
(VI) concentration of 30 ppm, and a contact time of 45 min. The adsorption
data were well fitted to the Langmuir isotherm and pseudo-second-order
kinetic models. The thermodynamic analysis indicated that the adsorption
process was endothermic and spontaneous at higher temperatures. The
modification of Zeolite Y with Zeolite Y/nZVI enhanced the adsorption
capacity from 0.9 mg/g to 7.1 mg/g.