Remediation of radioiodine using polyamine anion exchange resins

Capture of aqueous radioiodine species by metallated adsorbents from wastestreams of the nuclear power industry: a review

“…It must also be considered that many of the aqueous streams, from which iodine removal could be attempted, feature extreme pHs [21]. Even mildly acidic conditions change iodine speciation from predominantly iodide to more hydrophobic species, while a high pH entails high concentrations of hydroxide and possibly carbonate anions [22], which can severely limit the exchange of anions on to the solid phase, due to competition for binding sites [23][24][25].…”

“…IX is used widely for water treatment within the nuclear industry [26,27]. However, the harsh operational conditions already detailed preclude the use of conventional IX technology [23]. The competition from the many coexisting anionic Fig.…”

“…This is because it has historically been shown that the most effective chemistry for radioiodine immobilisation and retention is conversion to a stable iodide salt [7,15,28]. Yet, the hydrophobic nature of the resin matrix promotes interactions with more hydrophobic iodine species [23,29]. This complicates control of speciation in the adsorbent and the final wasteform stability.…”

“…This is possibly because the iodide anion is rather high in the known series of selectivity for conventional anion-exchange resins and in some conditions, established IX technology is sufficient for its effective removal [29,39]. However, with the remarkable chemical conditions that must be overcome within this remit, the application of HSAB is close to essential [23,24,40]. To the best of our knowledge, this is the first comprehensive review of metallated adsorbents for aqueous iodide immobilisation.…”

Calcium-loaded hydrophilic hypercrosslinked polymers for extremely high defluoridation capacity via multiple uptake mechanisms

“…The polyamine resin Purolite MTS9850 has an anion-exchange capacity of ~6.25 mmol•g -1 and the chelating resin Puromet MTS9501 (which has selectivity for alkali earth metals) has a reported cation-exchange capacity of only ~1.83 mmol•g -1 . 58,59 The capacity of HHCP2 was rather lower than expected in comparison, even given the extra mass present in the theoretical repeating unit of the polymer. This would suggest that HHCP2 featured a greater % of partial crosslinking, with the extra methoxy groups adding to the mass ( Figure S8).…”