A new way to ensure selective zirconium ion adsorption

This work studies the adsorption of zirconium ions by mesoporous titanium dioxide with surface arsenate groups. Experimental maximal adsorption values of zirconium ions were found to be 109.6 mg/g in neutral medium. This process depends on the interaction time, the equilibrium concentration of zirconium ions, and the acidity of the solution. Adsorption kinetics fit well into the kinetic model based on the pseudo-second-order equation (R${}^2$ = 0.9984). Equilibrium adsorption of zirconium ions is well described by Langmuir's adsorption theory (R${}^2$ = 0.9856 and χ${}^2$ = 1.307). Although zirconium ions are less actively adsorbed from a neutral medium than strontium or yttrium ions, in the 2% nitric acid only zirconium is adsorbed out of the mixture of zirconium, strontium, and yttrium. The results obtained by inductively coupled plasma mass spectrometry have shown that the investigated adsorbent selectively adsorbs zirconium ions from their mixture with strontium and yttrium in the range of solution acidity pH = 0–1. The average percentage of maximum extraction of zirconium ions is 94.3 ± 2.4%, and the highest percent of zirconium ions taken up from the mixture with strontium and yttrium is ∼98.4%. Investigated titanium dioxide selectively separate ${}^{90}$Zr from ${}^{90}$Sr with the presence of 1000-fold excess of stable ${}^{88}$Sr in radioactive liquid β${}^{\text{−}}$ source. This fact is extremely valuable for the age dating of ${}^{90}$Sr-containing device in nuclear forensics or the determination of ${}^{90}$Sr in low activity background samples.