Electrospinning of polyacrylonitrile nanofibers embedded with zerovalent iron and cerium oxide nanoparticles, as Cr(VI) adsorbents for water treatment

Abstract

Zerovalent iron (ZVI) and cerium oxide (CeO 2 ) nanoparticles (NPs) embedded in polyacrylonitrile nanofibers (NFs) were obtained via electrospinning. Each NF was characterized using Fourier transform infrared spectroscopy and X-ray diffraction. The scaffold morphology and average diameter of the NFs were determined using scanning electron microscopy (SEM). Energy dispersive X-ray spectroscopy (EDS) mapping and Raman spectroscopy were used to characterize the NPs dispersion in the NFs. The Cr(VI) removal efficiency (%E) of ZVI and CeO 2 NPs was compared with the efficiency of their corresponding NFs. CeO 2 NPs showed 79% Cr(VI) removal; the efficiency was better for their NFs (96%). Regeneration of ZVI NFs was 98 %E. ZVI NPs were the best adsorbent with 99.9% efficiency. An adsorption mechanism was proposed using Langmuir, Freundlich, and Temkin isotherm models. SEM-EDS analyses revealed that Cr adsorbed on the NP and NF surfaces.

The adsorption, kinetics, and interaction mechanisms of various types of estrogen on electrospun polymeric nanofiber membranes

“…The results indicate that the cumulative adsorption capacity of the four estrogenic hormones increased for each material until equilibrium was established between the adsorbates and adsorbent. The time to reach equilibrium depended on the concentration of the adsorbate and the amount of adsorbent [67]. Both factors were kept constant to compare the capacities of the different materials.…”

Electrospun polyurethane nanofibers coated with polyaniline/polyvinyl alcohol as ultrafiltration membranes for the removal of ethinylestradiol hormone micropollutant from aqueous phase

“…The experimental data set points adhere completely to the line of best fit, also observed by the high regression coefficient (R 2 ) of 0.998 and the calculated adsorption capacity of 2.16 mg/g is extremely close to the experimental value of 2.11 mg/g. The plausible reason that indicates these findings could be the inhomogeneous surface of available active sites on the modified adsorbent PU membrane since the adsorption rate is dependent on the concentration of hormone in the solution and the number of available sites that can actively accommodate the hormone [73]. All the supporting values of the given models are presented in Table 5.…”

Adsorption of Estrogenic Hormones in Aqueous Solution Using Electrospun Nanofibers From Waste Cigarette Butts: Kinetics, Mechanism, and Reusability

“…The results indicate that the cumulative of four EHs' adsorption capacity increases similarly for WCENFs until equilibrium was established between the adsorbates and adsorbent. The time to reach equilibrium depends on the concentration of adsorbate and the amount of adsorbent (Vazquez-Velez et al 2020). Both factors were kept constant to compare the capacities with the literature.…”

“…The regression coefficients are 0.99, and the calculated adsorption capacities of E2, EE2, and E1 are 0.544, 0.711, and 0.549 compared to the experimental values 0.532, 0.687, and 0.551, respectively. The slight difference indicates that the active sites were not homogenous on the surface because the adsorption rate is determined by the hormone concentration and the number of active sites available on the material(Vazquez-Velez et al 2020). These findings confirm the suitability of this model for describing E1, E2, and EE2 adsorption on WCENFs.…”