Abstract
Because of its excellent chelating property, ethylenediaminetetraacetic acid (EDTA) is used as a complex agent, not only for heavy metals, but also for radioactive isotopes during the decontamination of nuclear facilities. The removal of EDTA was investigated by adsorption with commercially available, gel-type, anion-exchange resins (AERs), which are based on cross-linked polystyrene with positive tertiary amine groups. Because of the positive charge on AERs, they could adsorb EDTA effectively even in a solution mixed with ions of cesium (Cs) via electrostatic attraction. Because EDTA adsorption by cation-exchange resins (CERs) was not possible, it was concluded that the negative charges on CERs do not contribute to the interaction with EDTA. The maximum adsorption capacity (qmax) of AER (2 g/L) for EDTA removal, calculated by the Langmuir isotherm model was 0.47 mmol/g for initial EDTA concentrations in the range of 0.01–1 mM in the EDTA/Cs mixed solution. The Langmuir isotherm model was found to be suitable for EDTA adsorption on AERs, indicative of monolayer adsorption. The results clearly suggested that the AERs could efficiently remove EDTA, regardless of the presence of nuclides, such as Cs ions in the aqueous solution.
Highlights
Because of its excellent chelating ability, ethylenediaminetetraacetic acid (EDTA) has been used as an adsorbent of heavy metal ions generated from the industrial processes [1,2], and in environmental pollutants (e.g., NOx and SO2 ) that cause acid rain and smog [3,4,5,6,7]
Most of the radioactive liquid wastes (RLWs), that are generated during the operation and from the decommissioning of nuclear power plants, usually contain a high EDTA concentration, with various kinds of surfactants [9,10]
The adsorption behavior of EDTA on the ion-exchange resins (IERs) was investigated under various adsorption conditions, such as adsorption time, initial EDTA concentration, pH, and the quantity of adsorbents used to elucidate the adsorption mechanism
Summary
Because of its excellent chelating ability, ethylenediaminetetraacetic acid (EDTA) has been used as an adsorbent of heavy metal ions generated from the industrial processes [1,2], and in environmental pollutants (e.g., NOx and SO2 ) that cause acid rain and smog [3,4,5,6,7]. Most of the radioactive liquid wastes (RLWs), that are generated during the operation and from the decommissioning of nuclear power plants, usually contain a high EDTA concentration, with various kinds of surfactants [9,10]. The adsorption technique has been applied to separate EDTA from liquid waste using various adsorbents, such as metal oxide [14,15,16], goethite [17], mesoporous silica [18], and activated carbon [19]. Ion-exchange resins (IERs), which are generally used in water treatment, could be a potential candidate for use in the separation and removal of EDTA in RLWs. IERs have been used as adsorbents for the purification or separation of biomaterials (e.g., proteins and amino acids) [22,23], pharmaceuticals [24], organic species (e.g., acids and alcohols) [25,26], CO2 [27], and metal ions [28,29]. The adsorption behavior of EDTA on the IERs was investigated under various adsorption conditions, such as adsorption time, initial EDTA concentration, pH, and the quantity of adsorbents used to elucidate the adsorption mechanism
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
