Adsorption of Ethylenediaminetetraacetic Acid on a Gel-Type Ion-Exchange Resin for Purification of Liquid Waste Containing Cs Ions

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.

Preparation of Slow-Release Insecticides from Biogas Slurry: Effectiveness of Ion Exchange Resin in the Adsorption and Release of Ammonia Nitrogen

“…The unit adsorption capacity decreased to 1.79 mg/g when the resin addition was 0.7 g. This adsorption law was consistent with the research results by Zhuang [27]. This may be due to the number of ammonia nitrogen exchange sites increasing with the increasing resin amount [28], and the unit utilization efficiency of the resin decreased with the increase in the resin content, which may have been due to the fact that the ammonia nitrogen could not completely contact the resin. After comprehensive consideration, the amount of resin selected was 0.5 g, which showed a significant (p < 0.05) difference from the other addition amounts.…”

Sustainable One-Pot Synthesis of 5-(Hydroxymethyl)furfural from C6-Sugars by Enhanced H+ Exchange Heterogeneous Catalysis

“…In contrast, dried Amberlyst 15 subjected to treatment in water containing NaCl exhibited changes in the stretching vibrations of the sulfonate group, as evidenced by peaks at 1124 and 1175 cm –1 , implying that the tetrahedrons of sulfonate are substantially distorted due to the formation of direct ionic bonds with Na + (Figure C). This alteration closely resembled the characteristics of the sulfonate group in its Na + form (dry) . For the dried Amberlyst 15 after treatment in the organic solvent (MIBK), with a minimal amount of water and NaCl, the intensity of stretching vibrations of the sulfonate group at 1175 cm × 1 significantly increased with increasing amount of water (1%, 3%), as shown in Figure D,E.…”

“…The cation exchanger, including Amberlyst 15, comprises a copolymer of styrene as a cross-linking agent with a sulfonate functional group. 23 Amberlyst 15 was treated by the addition of NaCl in both water and an organic solvent and subsequently dried at 120 °C for 2 h. The chemical structural characteristics of the dried Amberlyst 15 samples were confirmed and compared in terms of functional groups using FT-IR spectroscopy (Figure 2). The distinctive bands corresponding to the aromatic C�C stretching and aliphatic C−H vibrations were observed at 1682 and 2924 cm −1 , respectively.…”

“…This alteration closely resembled the characteristics of the sulfonate group in its Na + form (dry). 23 For the dried Amberlyst 15 after treatment in the organic solvent (MIBK), with a minimal amount of water and NaCl, the intensity of stretching vibrations of the sulfonate group at 1175 cm × 1 significantly increased with increasing amount of water (1%, 3%), as shown in Figure 2D,E. This observation indicates that the exchange of Na + and H + in the catalytic system resulted in the formation of the free H + form, which is capable of serving as an acidic catalyst.…”

Vanadium(V) Removal from Aqueous Solutions and Real Wastewaters onto Anion Exchangers and Lewatit AF5

“…For the SBA resins (A400TL, SR7, PSR3, and PSR2), the characteristic bands located at 830–890 cm −1 , e.g., 887, 833, and 826 cm −1 for A400TL originate from quaternary ammonium functional groups, R–N + –(CH 3 ) 3 , stretching vibrations, and the C-Cl stretching vibration of the CH 2 Cl groups, whereas for WBA resins, these bands were not observed [ 18 ]. Additionally, for SBA resins, the peaks at 1460–1480 cm −1 of the C–N vibrations of R–N + –(CH 3 ) 3 appeared [ 18 , 20 ]. In Figure 4 d the spectra of Lewatit AF5 are present by the ATR-FTIR method.…”