Evaluation of fluoride adsorption in solution by synthetic Al₂O₃/CeO₂: A fixed‐bed column study

Abstract

A highly efficient fluoride adsorbent Al2O3/CeO2 was synthesized in this work and used it to fluoride removal in the fixed‐bed adsorption through changing the different experimental conditions (influent F− concentration, flow velocity, and bed heights). The adsorption capacity was 9.72 mg/g. In addition, the Adams–Bohart and Thomas models were used to fit and evaluate the column breakthrough curve of fluoride removal process by Al2O3/CeO2, and the correlation coefficients (R2) of the Thomas model were close to 1 under all experimental conditions. The structure of Al2O3/CeO2 and the adsorption mechanism were confirmed by X‐ray diffraction (XRD), Fourier‐transform infrared spectroscopy (FT‐IR), N2 adsorption and desorption isotherm, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X‐ray photoelectron spectroscopy (XPS). Moreover, the adsorption of fluoride (F−) was mainly through metal binding (MF) and hydroxyl binding (AlOH⋯F) on the surface of the Al2O3/CeO2. Furthermore, the regeneration and coexisting anions studies of Al2O3/CeO2 were carried out, and the efficiency of adsorption was still above 70% after five cycles. Practitioner Points Removal of fluoride was studied by fixed‐bed experiment, and the adsorption capacity of composite Al2O3/CeO2 was 9.72 mg/g. The metal complex played important role in fluoride removal and reusability makes a long‐term application for fluoride adsorption. Fluoride wastewater is pumped to the fixed‐bed column, and fluoride ions are absorbed by Al2O3/CeO2 through fluoride metal complex and aluminum hydrofluoride.

A dense structure constructed by flake and spherical aluminum: Simultaneously enhanced anti‐wear and anti‐corrosion properties of epoxy/polytetrafluoroethylene composite coatings

“…CF bonds appeared in the spectra of C 1s (Figure 10b) and F 2p (Figure 10d), 35,36 demonstrating that part of PTFE was transferred to the dual surface. In addition, peaks of metal fluorides (MF n ) (M = Fe, Al, et al), FeF 3 , FeF 2 and Al‐F appeared in the XPS spectrums of F 2p, 37 Fe 2p 38 and Al 2p, 39 respectively (Figure 10d–f), which was attributed to the tribochemical reactions taking place between PTFE and metal dual ball or Al powders. During sliding friction, the CC or CF main chain bonds of PTFE will break, under the action of oxygen and water molecules in the atmosphere, carboxyl groups were formed, and the carboxyl groups can chelate to the steel ball or Al powders, 37,40 thereby forming a robust tribofilm.…”

Application of artificial neural network for prediction of fluoride removal efficiency using neutralized activated red mud from aqueous medium in a continuous fixed bed column.

“…The continuous xed bed column potentiality was evaluated by the breakthrough time period and removal quantity given in Eq. 1 (Chen et al 2021;Tor et al 2009). To know the effective efforts of the xed bed glass column systems applying various easy numerical models were succeeded.…”

“…Arti cial neural network (ANN) is a powerful prediction tool for the identi cation of the relevant parameters and their correlation relationships are very complex. Removal of toxicants from aqueous solutions using different prediction models has been used current time by numbers of researchers (Chen et al 2021;Wan et al 2021).…”

The Constructing of the Oxide Phase Diagram for Fluoride Adsorption on La-Fe-Al: A Collaborative Study of Density Functional Calculation and Experimentation

“…For example, activated alumina has a large specific surface area and a rich aperture structure. It is the most common kind of fluoride-removal adsorbent [28,29]. Relevant studies have shown that Fe is a typical transition metal, widely distributed in environmental minerals.…”