Adsorption of 60Co(II) and 152+154Eu(III) radionuclides by a sustainable nanobentonite@sodium alginate@oleylamine nanocomposite.

A sustainable and efficient nanobentonite@sodium alginate@oleylamine (Nbent@Alg@OA) nanocomposite has been successfully synthesized via coating reaction of nanobentonite (Nbent) with alginate (Alg) and oleylamine (OA). The nanocomposite has been characterized and examined for the adsorption of 60Co(II) and 152+154Eu(III) radionuclides from simulated radioactive waste solution. FT-IR, XRD, SEM, and HR-TEM techniques have been applied to confirm the structural and morphological characteristics of the Nbent@Alg@OA nanocomposite. The effects of various parameters, such as pH of the medium, initial concentration of the radionuclides, contact time, and temperature on the adsorption of 60Co(II) and 152+154Eu(III) radionuclides were investigated by the batch adsorption technique. The results revealed that the optimum pH values for the adsorption of 152+154Eu (III) and 60Co (II) radionuclides were 4 and 5, respectively. The adsorption capacity of 152+154Eu(III) (65.6219 mg/g) was found greater than that of 60Co(II) (47.3469 mg/g). The adsorption process was found to be well described by the pseudo-second-order kinetic model. Furthermore, the equilibrium isotherm evaluation revealed that the Langmuir model was adequately matched with the adsorption data. According to the thermodynamic characteristics, the adsorption process was endothermic and spontaneous. Regeneration and reuse of Nbent@Alg@OA nanocomposite confirmed that the recycled nanocomposite was sufficiently efficient in several successive practical applications.

Promoted adsorptive removal of chromium(vi) ions from water by a green-synthesized hybrid magnetic nanocomposite (NFe3O4Starch-Glu-NFe3O4ED).

A novel magnetic starch-crosslinked-magnetic ethylenediamine nanocomposite, NFe3O4Starch-Glu-NFe3O4ED, was synthesized via microwave irradiation. The characteristics of the assembled NFe3O4Starch-Glu-NFe3O4ED nanocomposite were evaluated via XRD, FT-IR, TGA, BET, SEM and HR-TEM analyses. Its particle size was confirmed to be in the range 11.25-17.16 nm. The effectiveness of the designed nanocomposite for the removal of Cr(vi) ions was explored using the batch adsorption technique. Equilibrium results proved that the adsorptive removal of the target metal ions from aqueous solution was highly dependent on the optimized experimental parameters. The maximum adsorptive removal percentage values (%R) of Cr(vi) ions on NFe3O4Starch-Glu-NFe3O4ED obtained at pH 2.0 were 85.27%, 91.90%, and 96.47% using 10.0, 25.0, and 50.0 mg L-1 Cr(vi), respectively, for an equilibrium time of 30 min. The adsorption process was found to be strongly influenced by the presence of interfering salts including NaCl, CaCl2, KCl, MgCl2, and NH4Cl. Kinetic studies were performed and it was found that the pseudo-second and Elovich models well fitted the experimental data with the possible suggested ion-pair interaction mechanism. Different isotherm models were employed to assess the adsorption equilibrium, which was revealed by fitting Langmuir, Temkin and Freundlich models. The maximum uptake capacity based on the Langmuir model was 210.741 mg g-1. The effect of temperature and thermodynamics confirmed that adsorption was spontaneous, feasible, and endothermic in nature. Finally, the validity and applicability of using the NFe3O4Starch-Glu-NFe3O4ED nanocomposite to remove Cr(vi) ions from real water matrices were confirmed in the range of 91.2-94.7 ± 2.2-3.7%.

Nano-manganese oxide-functionalized-oleyl amine as a simple and low cost nanosorbent for remediation of ZnII/CoII and their radioactive nuclides 65Zn and 60Co from water.

The contribution of oleyl amine as a biodegradable and simple aliphatic compound containing amine functional group (-NH2) was discussed in this work with respect to the remediation process of heavy metal ions from aqueous solution. Manganese oxide nanoparticles were synthesized via combustion synthesis and then functionalized with oleyl amine to form a new nanosorbent (NMn3O4-OA).The characteristics of this nanosorbent were examined using different instruments, such as Fourier-transform infrared spectroscopy, thermal gravimetric analysis, X-ray powder diffraction and high-resolution transmission electron microscopy. The HR-TEM images confirmed nanoscale range for NMn3O4-OA between 41.30 and 61.86 nm. The influence of diverse parameters on remediation of ZnII/CoII was examined, involving pH of metal ion solutions (pH 1-7), reaction time (1-60 min), solid amount (5-100 mg) and ionic concentration (0.1-2.0 mol/L). The optimum conditions were found pH 7 and 5-20 min reaction time for the two metal ions. The maximum capacities for adsorptive remediation were found 202 and 100 mgg-1for ZnII and Co II, respectively.

A novel nanocomposite of Liquidambar styraciflua fruit biochar-crosslinked-nanosilica for uranyl removal from water.

Biochar adsorption has been protruded as a sustainable green and economic process for water remediation. This technology is facing high challenges in removing different pollutants, owning to the stable chemical and physical features of biochar. Therefore, a novel nanocomposite of Liquidambar styraciflua fruit biochar-crosslinked-nanosilica (BC-Gl-NSi) was synthesized and characterized (surface area = 60.754 m2 g-1 and particle size = 17.32-36.25 nm). The designed BC-Gl-NSi nanocomposite was explored for removal of uranyl ions by the batch adsorption technique under the influence of different factors including temperature, contact time, nanocomposite dosage, pH, uranyl ion concentration as well as co-existing ions. The adsorption process was principally confirmed to rely on the solution pH and reached 86.3% in pH 4.0. The results showed also that one-minute contact duration was sufficient to reach the maximum extraction of uranyl (30.0 mg L-1). Besides, [BC-Gl-NSi] exhibited excellent selectivity and good recovery of uranyl ions with other competing ions.