Enhanced surface decontamination of radioactive Cs by self-generated, strippable hydrogels based on reversible cross-linking

• Published in: Journal of hazardous materials Vol. 362; pp. 72 - 81
• Main Authors: Yang, Hee-Man, Park, Chan Woo, Lee, Kune-Woo
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.01.2019
• Subjects: Magnetic separation; Phenylboronic acid-diol ester bond; Radioactive cesium; Strippable hydrogel; Surface decontamination; Strippable hydrogel; Phenylboronic acid-diol ester bond; Magnetic separation; Radioactive cesium; Surface decontamination
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2018.08.064

•A self-generated, strippable hydrogel containing adsorbents was developed for surface decontamination.•The hydrogel is composed of polyvinyl alcohol and phenylboronic acid grafted alignate.•The strippable hydrogel effectively removed 137Cs from the various surfaces including a porous cement surface.•A new eco-friendly volume-reduction method for radioactive waste was suggested. A self-generated, strippable hydrogel containing adsorbents was developed to remove the radioactive cesium from surfaces by adsorption for wide-area surface decontamination. Two aqueous polymeric solutions of polyvinyl alcohol (PVA) and phenylboronic-acid-grafted alginate (PBA-Alg) were easily applied to surfaces and subsequently self-generated a hydrogel based on the PBA-diol ester bond. Compared to the strippable coating and chemical gels, the PBA-diol ester bond-based hydrogel was easily peeled off the surfaces without a drying step due to its high elasticity, which is more practical and time saving. The resulting hydrogel displayed high 137Cs removal efficiencies of 91.61% for painted cement, 97.505% for aluminum, 94.05% for stainless steel, and 53.5% for cement, which was 2.3 times higher than that of Decongel due to the presence of the adsorbent in the hydrogel having an excellent Cs distribution coefficient (3.34 × 104 mL/g). Moreover, the volume of radioactive waste generated after the surface decontamination could be reduced by a simple magnetic separation of the adsorbent from the used hydrogel, which can reduce the waste disposal cost. Therefore, our hydrogel system has great potential as a new, cost-effective surface decontaminant in various nuclear industry fields including wide-area environmental remediation after a nuclear accident or terrorist attack.