Preparation of Graphene Oxide-Maghemite-Chitosan Composites for the Adsorption of Europium Ions from Aqueous Solutions

• Published in: Molecules (Basel, Switzerland) Vol. 27; no. 22; p. 8035
• Main Authors: Lujanienė, Galina, Novikau, Raman, Joel, Edith Flora, Karalevičiūtė, Karolina, Šemčuk, Sergej, Mažeika, Kęstutis, Talaikis, Martynas, Pakštas, Vidas, Tumėnas, Saulius, Mažeika, Jonas, Jokšas, Kęstutis
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 19.11.2022; MDPI
• Subjects: Adsorbents; Adsorption; Aqueous solutions; Chitosan; composite; Composite materials; Efficiency; Eu(III); Europium; Graphene; graphene oxide; Ions; Iron oxides; maghemite; Mossbauer spectroscopy; Nanomaterials; Nanoparticles; Natural waters; Neural networks; Nuclear energy; Nuclear power plants; Physical characteristics; Pollutants; Radioactive wastes; Raman spectroscopy; Spectroscopy; Spectrum analysis; Germany; chitosan; graphene oxide; Eu(III); adsorption; composite; ANFIS; maghemite
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules27228035

The adsorption of Eu(III) on composites synthesised from graphene oxide (GO), maghemite (MGH), and chitosan (CS) has been studied using different approaches. The physicochemical and morphological characteristics of the composites GO-MGH, GO-CS, GO-MGH-CS I, II, and III were determined by XRD, Mössbauer spectroscopy, FTIR, Raman spectroscopy, and TEM. According to the results of batch experiments, the maximum experimental adsorption capacity was 52, 54, 25, 103, and 102 mg/g for GO-MGH, GO-CS, GO-MGH-CS I, II, and III, respectively. The data obtained are in better agreement with the Langmuir, pseudo-second-order, and pseudo-first-order models only for GO-MGH. Thus, the adsorption of Eu(III) on the composites was a favourable, monolayer, and occurred at homogeneous sites. The nature of adsorption is chemical and, in the case of GO-MGH, physical. Tests of the composites in natural waters showed a high removal efficiency for Eu(III), Pu(IV), and Am(III), ranging from 74 to 100%. The ANFIS model has quite good predictive ability, as shown by the values for R , MSE, SSE, and ARE. The GO-MGH-CS composites with the high adsorption capacity could be promising candidates for the removal of Eu(III) and the pre-concentration of Pu(IV) and Am(III) from natural waters.