Strippable Polymeric Nanocomposites Comprising “Green” Chelates, for the Removal of Heavy Metals and Radionuclides

Abstract

The issue of heavy metal and radionuclide contamination is still causing a great deal of concern worldwide for environmental protection and industrial sites remediation. Various techniques have been developed for surface decontamination aiming for high decontamination factors (DF) and minimal environmental impact, but strippable polymeric nanocomposite coatings are some of the best candidates in this area. In this study, novel strippable coatings for heavy metal and radionuclides decontamination were developed based on the film-forming ability of polyvinyl alcohol, with the remarkable metal retention capacity of bentonite nanoclay, together with the chelating ability of sodium alginate and with “new-generation” “green” complexing agents: iminodisuccinic acid (IDS) and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC). These environmentally friendly water-based decontamination solutions are capable of generating strippable polymeric films with optimized mechanical and thermal properties while exhibiting high decontamination efficiency (DF ≈ 95–98% for heavy metals tested on glass surface and DF ≈ 91–97% for radionuclides 241Am, 90Sr-Y and 137Cs on metal, painted metal, plastic, and glass surfaces).

Natural Polymers and Their Nanocomposites Used for Environmental Applications

“…Soil can be affected by pollution with heavy metals or radionuclides, having a severe consequence on ecosystems and human health [ 84 , 134 , 135 , 136 , 137 ]. 137 Cs, 90 Sr, and uranium are the most known radioactive isotopes, which present a significant danger for the modern world [ 138 ]. Moreover, the presence of nanomaterials and bioplastics in soils requires specific materials to be able to entirely biodegrade the polymers in the soil and thus maintain the ecological restoration and soil quality.…”

“…The PVA/bentonite nanoclay/sodium alginate/iminodisuccinic acid (IDS) or 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC) nanocomposites were prepared by Toader et al [ 138 ] by a casting method for surface decontamination of environmentally friendly water solutions. Their testing showed a decontamination efficiency (DF) in the range of 95–98% and 91–97% for heavy metals tested on a glass surface and the radionuclides 241 Am, 90 Sr-Y, and 137 Cs on metal, painted metal, plastic, and glass surfaces, respectively.…”

Peelable Nanocomposite Coatings: “Eco-Friendly” Tools for the Safe Removal of Radiopharmaceutical Spills or Accidental Contamination of Surfaces in General-Purpose Radioisotope Laboratories

“…The decontamination process with the peelable coatings method is possible via two main mechanisms: complexation and adsorption [25]. Figure S6 (from the Supporting info One of the major objectives of this study was to establish the adequate composition of the decontaminating formulation, for achieving maximal results in terms of decontamination efficiency.…”

“…Owing to their ecological composition and design, these formulations can significantly reduce the volume of waste generated after decontamination, while still ensuring a high decontamination efficiency. These innovative, inexpensive, 'eco-friendly', strippable nanocomposite films, designed for radionuclides decontamination, were obtained from water-based, non-toxic, formulations comprising readily biodegradable [21][22][23] components: polymeric matrices (gelatin, sodium alginate, polyvinyl alcohol), a new generation [12,24,25] 'green' chelating agent (iminodisuccinic acid), glycerol, and bentonite nanoclay. These new formulations are suitable for the decontamination of the surfaces (e.g., workbenches, sinks, gloveboxes, flooring, etc.)…”

Peelable Alginate Films Reinforced by Carbon Nanofibers Decorated with Antimicrobial Nanoparticles for Immediate Biological Decontamination of Surfaces

“…Depending on the polymeric matrix, the active ingredients, solvents, and compositions being employed, the coatings possess variable physical and chemical properties that make them suitable for a particular application [13]. Several types of peelable coatings have been developed for decontamination purposes [9,10,13,[19][20][21][22][23][24][25][26][27]. However, there are fewer publications on biological decontamination of surfaces than on radioactive or CWA contaminants.…”