Removal of Cr(VI) from Wastewater Using Graphene Oxide Chitosan Microspheres Modified with α–FeO(OH)

Abstract

Graphene oxide and chitosan microspheres modified with α–FeO(OH) (α–FeO(OH)/GOCS) are prepared and utilized to investigate the performance and mechanism for Cr(VI) removal from aqueous solutions and the possibility of Fe secondary pollution. Batch experiments were carried out to identify the effects of pH, mass, and volume ratio (m/v), coexisting ions, time (t), temperature (T), and Cr(VI) initial concentration (C0) on Cr(VI) removal, and to evaluate adsorption kinetics, equilibrium isotherm, and thermodynamics, as well as the possibility of Fe secondary pollution. The results showed that Cr(VI) adsorption increased with C0, t, and T but decreased with increasing pH and m/v. Coexisting ions inhibited Cr(VI) adsorption, and this inhibition increased with increasing concentration. The influence degrees of anions and cations on the Cr(VI) adsorption in descending order were SO42− > PO42− > NO3− > Cl− and Ca2+ > Mg2+ > Mn2+, respectively. The equilibrium adsorption capacity of Cr(VI) was the highest at 24.16 mg/g, and the removal rate was 97.69% under pH = 3, m/v = 1.0 g/L, T = 298.15 K, and C0 = 25 mg/L. Cr(VI) adsorption was well fitted to a pseudo-second-order kinetic model and was spontaneous and endothermic. The best fit of Cr(VI) adsorption with the Langmuir and Sips models indicated that it was a monolayer and heterogeneous adsorption. The fitted maximum adsorption capacity was 63.19 mg/g using the Sips model under 308.15 K. Cr(VI) removal mainly included electrostatic attraction between Cr(VI) oxyanions with surface Fe–OH2+, and the adsorbed Cr(VI) was partially reduced to Cr(III) and then precipitated on the surface. In addition, there was no Fe secondary pollution during Cr(VI) adsorption.

Synergistic effect of metals and cross linkers on surface modification of iron aluminum oxyhydroxide‐PVA polymer films for enhanced catalytic activity in transesterification reaction

“…The stretching vibration of ‐OH is responsible for the band at 3406 cm −1 . The band at 1642 cm −1 is attributed to the symmetric bending of C=O in FeOOH, 23 and the bending vibration of FeOOH gives rise to the bands at 528 cm −1 24 . The FTIR spectrum of the cross‐linked films shows the formation of cross‐links between PVA and GA.…”

“…The band at 1642 cm À1 is attributed to the symmetric bending of C=O in FeOOH, 23 and the bending vibration of FeOOH gives rise to the bands at 528 cm À1 . 24 The FTIR spectrum of the cross-linked films shows the formation of cross-links between PVA and GA. The band of -OH stretching becomes narrower due to the cross-linking between the functional groups of PVA and GA.…”

Iodide ion-imprinted chitosan beads for highly selective adsorption for nuclear wastewater treatment applications

“… Suitable for the adsorption of adsorbates that are responsive to magnetic fields in which the FeO changes the magnetization dynamics of the beads. [ 48 , 54 ] SiO 2 Anionic dye (AR73) N/A 1)Enhanced Adsorption capacity of the dye anions. Improve the mechanical, interfacial, and thermal properties.…”

Removal of Toxic Hexavalent Chromium from Wastewater by Activated Carbon Generated from Liming Pelt Trimming with Tannin

“…The polyamine-modified carbon nanotubes (PA-CNTs) have been introduced to remove Cr(VI) (Liu et al 2023;Jia et al 2022). Graphen oxide-CaO, Graphen oxide-CaO and graphene Oxide chitosan α-FeO(OH) hybrid nanocomposite have been developed to remove Cr(VI) from wastewater (Singh et al 2022 a;Singh et al 2022 b;Liu et al 2022). Recently, surface modified water hyacinth , coconut tree fiber (Kumari et al 2020), poly-aniline coated sugarcane bagasse were employed as an adsorbent to remove Cr(VI).…”