Á¦¸ñ | Design and Application of Materials for Sequestration and Immobilization of 99Tc (2023) | ||||
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Design and Application of Materials for Sequestration and Immobilization of 99Tc (2023)
Bhupendra Kumar Singh, Nurul Syiffa Mahzan, Nur Shahidah Abdul Rashid, Samiratu Atibun Isa, Muhammad Aamir Hafeez, Sarah Saslow, Guohui Wang, Changki Mo, and Wooyong Um
Environmental Science and Technology, 57, 6776-6798
DOI: https://doi.org/10.1021/acs.est.3c00129
ABSTRACT
99Technetium (99Tc) is a hazardous radionuclide that poses a serious environmental threat. The wide variation and complex chemistries of liquid nuclear waste streams containing 99Tc often create unique, site specific challenges when sequestering and immobilizing the waste in a matrix suitable for long-term storage and disposal. Therefore, an effective management plan for 99Tc containing liquid radioactive wastes (such as storage (tanks) and decommissioned wastes) will likely require a variety of suitable materials/matrixes capable of adapting to and addressing these challenges. In this review, we discuss and highlight the key developments for effective removal and immobilization of 99Tc liquid waste in inorganic waste forms. Specifically, we review the synthesis, characterization, and application of materials for the targeted removal of 99Tc from (simulated) waste solutions under various experimental conditions. These materials include (i) layered double hydroxides (LDHs), (ii) metal–organic frameworks (MOFs), (iii) ion-exchange resins (IERs) as well as cationic organic polymers (COPs), (iv) surface modified natural clay materials (SMCMs), and (v) graphene-based materials (GBMs). Second, we discuss some of the major and recent developments toward 99Tc immobilization in (i) glass, (ii) cement, and (iii) iron mineral waste forms. Finally, we present future challenges that need to be addressed for the design, synthesis, and selection of suitable matrixes for the efficient sequestration and immobilization of 99Tc from targeted wastes. The purpose of this review is to inspire research on the design and application of various suitable materials/matrixes for selective removal of 99Tc present globally in different radioactive wastes and its immobilization in stable/durable waste forms.
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