ASSESSMENT OF IODINE REMOVAL EFFICIENCY OF SORBENT MATERIALS THROUGH BATCH AND CONTINUOUS FLOW EXPERIMENTS AND THEIR FORMULATION INTO CONSOLIDATION WASTE FORMS

Abstract

The development of nuclear power has always been accompanied by the problem of the safe operation of nuclear power plants. This research focuses on iodine capture using MOFs, immobilization, and safe disposal were important issues for the development of nuclear power. In particular, several function materials were developed, formulated into different structures, and investigated for iodine capture and immobilization using gas or aqueous phase. Metal-organic frameworks (MOFs) were investigated thoroughly for iodine capture from off-gas streams; however, fewer studies have systematically investigated the performance and structure-property relationships of MOFs on iodine removal. In the first part of the research, Zr-UiO-66 and Ni-MOF-74 were successfully synthesized ad adsorbents for iodine in cyclohexane solution. Adsorption temperature, iodine concentration, and ion interference were investigated in the performance of iodine capture. Ni-MOF-74 outperformed Zr-UiO-66 in immobilizing iodine from the solution by achieving a maximum iodine removal efficiency of 97% at 60 °C Besides the results showed that the presence of other interfering ions marginally affects the iodine removal efficiency over both MOF sorbents. Then, continuous-flow experiments were conducted to assess the efficacy of these candidate adsorbents under more realistic conditions. The second part of the research focuses on addressing this issue by converting these iodine-laden MOFs into suitable waste consolidated forms for long-term disposal. Cement type III was used to solidify and stabilize the waste for disposal. The obtained findings show that the ability of the cement waste form to permanently trap iodine for safe geological disposal.