Removal of Cr (III) and Cr (VI) ions by adsorbent based on Titanium Dioxide

In this paper, the adsorption of trivalent chromium cations by a sample of sodium-modified TiO2 was studied. XRF analysis of the TiO2 surface was performed. The dependence of the adsorption value on the duration of the interaction in the system of the adsorbent–solution of chromium compound was investigated. The influence of the acidity of the solution and the equilibrium concentration of chromium ions on the adsorption value was also determined. It is shown that the adsorption kinetics of trivalent chromium ions is best described by the pseudo-second-order equation and the diffusion kinetic model. Freundlich's adsorption theory best describes equilibrium adsorption. Mass spectrometry proved the enhanced adsorption of trivalent chromium ions from a mixture with hexavalent chromium. This statement was evidenced by Raman spectroscopy of the surface of Na-TiO2. The maximum adsorption of Cr (III) ions is 62 mg/g. The separation factor of trivalent chromium and hexavalent chromium is 7.279