Simply synthesized sodium alginate/zirconium hydrogel as adsorbent for phosphate adsorption from aqueous solution: Performance and mechanisms. (March 2022)

• Record Type: Journal Article
• Authors: Qing, Zhuolin; Wang, Liangjie; Liu, Xinyao; Song, Zhiwei; Qian, Feng; Song, Yonghui
• Is Part Of: Chemosphere. Volume 291:Part 3(2022)
• Publication Date: 2022-03
• Subjects: Sodium alginate/zirconium hydrogel -- Phosphate -- Adsorption -- Electrostatic attraction -- Hydrogen bonding -- Ligand exchange; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.133103
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The traditional zirconium hydrogel beads were synthesized by multi-step method, which was comparatively complex. In this study, a high phosphate removal efficient sodium alginate/zirconium (SA/Zr) hydrogel was synthesized by a simple method, with the phosphate adsorption performance and mechanism be explored. The results showed that the adsorption capacity of SA/Zr hydrogel to phosphate was greatly affected by pH. With the increase of initial pH (3–11), the adsorption capacity of SA/Zr for phosphate descended. The phosphate adsorption capacity of SA/Zr hydrogel exceeded 120 mg PO4 3− /g at pH 2–7, while reaching the maximum adsorption capacity at pH 3 (256.79 mg PO4 3− /g). The process of adsorption kinetics was well fitted by intraparticle diffusion model, indicating that there was chemical adsorption during the adsorption process. The Redlich-Peterson isotherm model can well accord with isotherm data. In addition, the material showed high selectivity to phosphate. Besides, combining X-ray photoelectron spectroscopy with Zeta potential results suggested that when the pH value was less than 4.19, SA/Zr hydrogel adsorbed phosphate by electrostatic attraction and hydrogen bonding while the adsorption was made mainly through ligand exchange when pH value was higher than 4.19. Graphical abstract: Image 1 Highlights: Sodium alginate/zirconium (SA/Zr) hydrogel was prepared by a simply method. The maximum phosphate adsorption capacity of SA/Zr hydrogel was 246.23 mg/g. The material adsorbed phosphate by electrostatic attraction, hydrogen bonding and ligand exchange. The adsorbent showed high selectivity to phosphate.