Radiation induced modified CMC-based hydrogel with enhanced reusability for heavy metal ions adsorption

The study attempted solving hazardous heavy-metal problems by creating a new eco-friendly functional hydrogel adsorbent (CSB-hydrogel). By utilizing γ-irradiation induced grafting and co-polymerization, the CSB-hydrogels were synthesized from a main bio-polymer {Sodium Carboxymethyl Cellulose (CMC)} and two active vinyl monomers {Sodium Styrene Sulfonate (SSS) and Bis[2-(Methacryloyloxy)Ethyl] Phosphate (BMEP)}. As well as the compression moduli, the CSB-hydrogels showed significant difference in the swelling capacities with the variety of BMEP-amounts. The author then examined the CSB-hydrogels’ multi-metal-ion adsorption capacities by performing the ion-capturing experiments with a varying species mixture solution and by utilizing ICP-MS analysis technique. The CSB-hydrogels demonstrated their highly-efficient recovery functionalities for most of the metal ions in the solution; especially, higher than 70% for nickel. Moreover, the CSB-hydrogels showed sufficient performance after 4-time repetitive adsorption-desorption treatments. With the high heavy-metal capturing-efficiency and the re-usability, the CSB-hydrogels were revealed to have a high potential as a new eco-friendly environment-purifying material.