Adsorption of Rare Earths(Ⅲ) Using an Efficient Sodium Alginate Hydrogel Cross-Linked with Poly-γ-Glutamate

Abstract

With the exploitation of rare earth ore, more and more REEs came into groundwater. This was a waste of resources and could be harmful to the organisms. This study aimed to find an efficient adsorption material to mitigate the above issue. Through doping sodium alginate (SA) with poly-γ-glutamate (PGA), an immobilized gel particle material was produced. The composite exhibited excellent capacity for adsorbing rare earth elements (REEs). The amount of La3+ adsorbed on the SA-PGA gel particles reached approximately 163.93 mg/g compared to the 81.97 mg/g adsorbed on SA alone. The factors that potentially affected the adsorption efficiency of the SA-PGA composite, including the initial concentration of REEs, the adsorbent dosage, and the pH of the solution, were investigated. 15 types of REEs in single and mixed aqueous solutions were used to explore the selective adsorption of REEs on gel particles. Scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy analyses of the SA and SA-PGA gel beads suggested that the carboxyl groups in the composite might play a key role in the adsorption process and the morphology of SA-PGA changed from the compact structure of SA to a porous structure after doping PGA. The kinetics and thermodynamics of the adsorption of REEs were well fit with the pseudo-second-order equation and the Langmuir adsorption isotherm model, respectively. It appears that SA-PGA is useful for recycling REEs from wastewater.

Simultaneous Removal and Recovery of Metal Ions and Dyes from Wastewater through Montmorillonite Clay Mineral

“…To the best of the authors' knowledge, no data related to the adsorption of Ce(III) cations onto K10-Mt are available. The adsorption capacity values reported in literature for the uptake onto different supports [115][116][117] are of the same order of magnitude or lower than those obtained in the present work.…”

Complexation and conformation of lead ion with poly-γ-glutamic acid in soluble state

“…The molecular structure of γ-PGA contains amide linkages between the γ-amino and γ-carboxylic acid functional groups, leaving the γ-carboxylate group available for cation binding. The γ-PGA is of a particular research interest because of its potential implication in the removal of heavy metals in water treatment [16, 17]. The γ-PGA showed a great affinity to Cu(II), Al(III), Cr(III), Fe(III) and Pb(II), which induce flocculation [18–20].…”

Characteristics of novel polymer based on pseudo-polyamino acids GluLa-DPG-PEG600: binding of albumin, biocompatibility, biodistribution and potential crossing the blood-brain barrier in rats

“…It has been developed poly mers based on amino acids with good biocompati bility like hydrogel based on poly γ-glutamic acid (γ-PGA) and ε-polylysine (ε-PL) or able to adsorb rare earth elements like sodium alginate hydrogel linked with poly-γ-glutamate [2,3]. Scientists also developed specific polymers for drug delivery, for example lysinebased hydrogels for the oral delivery which are pHsensitive or safe detoxifying agent like poly(γ-glutamic acid) [4,5].…”