Adsorption Characteristics of Zr(Ⅳ) From Nitric Acid Solution Using a Silica-Based Macroporous HDEHP Adsorbent

A silica-based HDEHP/SiO₂-P adsorbent was synthesized to adsorb Zr(Ⅳ) from nitric acid solution. The adsorption behavior of Zr(Ⅳ) from nitric acid solution containing some typical fission products (FPs) was studied. The adsorbent exhibited much higher affinity for Zr(Ⅳ) over other FPs within a wide HNO₃ concentration range. Also, the obtained results indicate that the Zr(Ⅳ) adsorption capacity reaches to 0.456 mmol/g at 298 K. The adsorption kinetics and isotherm are well described by the pseudo-second-order model and the Langmuir equation, respectively. Adsorbed Zr(Ⅳ) onto HDEHP/SiO₂-P can be effectively eluted by H₂C₂O₄ solution in equilibrium time of about 1 h, and the desorption ratio reaches 98%.