Sorption of radiocobalt and its EDTA complex on titanium antimonates

Capture of Co(II) from its aqueous EDTA-chelate by DTPA-modified silica gel and chitosan

“…However, this waste is still hazardous and has to be treated and stored properly. Many of the liquid waste streams from NPPs contain chelating agents, such as EDTA, originating from cleaning solutions used to decontaminate NPP structures [11]. Treatment of radioactive waste containing chelating agents by conventional methods like non-specific ion exchangers, precipitation or mixing with cement produces large amounts of waste to treat and dispose of [12,13].…”

“…Such materials are, for example, titanium antimonates [11], clay minerals [15], commercial anion exchangers [7,16], commercial cation exchangers [17], copolymers with amino groups [18], polyethyleneimine-agarose [19], and chitosan [20][21][22][23]. The studies above were based on either cation exchange between a dissolved metal-EDTA chelate and the ion exchanger or anion exchange where the whole metal-EDTA chelate was adsorbed.…”

“…The aim of this work was to study the applicability of DTPAfunctionalized silica gel and chitosan [24,25] to the adsorption of Co(II) in the presence of EDTA. Co(II) was selected as the target metal because its radioactive isotope 60 Co is one of the most problematic waste nuclides, with quite a long half-life (5.2 years) and high gamma decay energy [11]. DTPA-modified silica gel [24] and chitosan [25] have been found to be effective adsorbents for Co(II) from pure metal solutions.…”

Degradation of a cobalt(II)–EDTA complex by photocatalysis and H2O2/UV-C. Application to nuclear wastes containing 60Co

“…Some low-level liquid wastes contain radioactive 60 Co, which can be either trapped to suspended materials or formed complexes with organic compounds [4][5][6]. These effluents can be filtered to remove the particulate cobalt, but the soluble forms of cobalt require the use of other methods, such as (i) precipitation or (ii) ion exchange on either organic resins [7] or highly selective inorganic ion exchangers such as titanates [8]. These methods are unfortunately not suitable for use with soluble cobalt complexes.…”

“…These methods are unfortunately not suitable for use with soluble cobalt complexes. Ethylenediaminetetraacetic acid (EDTA) is one of the most ubiquitous ligands present in these low activity effluents because it is widely used at nuclear facilities for cleaning and decontamination purposes [7,9]. Cobalt and EDTA form a highly stable and soluble 1:1 complex (Fig.…”