Effect of the magnetic core in alginate/gum composite on adsorption of divalent copper, cadmium, and lead ions in the aqueous system

Khalid Z Elwakeel; Marwan M Ahmed; Abdullah Akhdhar; Huda M Alghamdi; Mohamed G M Sulaiman; Mohammed F Hamza; Ziya A Khan

doi:10.1016/j.ijbiomac.2023.126884

Effect of the magnetic core in alginate/gum composite on adsorption of divalent copper, cadmium, and lead ions in the aqueous system

Int J Biol Macromol. 2023 Dec 31;253(Pt 4):126884. doi: 10.1016/j.ijbiomac.2023.126884. Epub 2023 Sep 12.

Authors

Khalid Z Elwakeel¹, Marwan M Ahmed², Abdullah Akhdhar², Huda M Alghamdi², Mohamed G M Sulaiman², Mohammed F Hamza³, Ziya A Khan²

Affiliations

¹ University of Jeddah, College of Science, Department of Chemistry, Jeddah, Saudi Arabia; Environmental Chemistry Division, Environmental Science Department, Faculty of Science, Port Said University, Port Said, Egypt. Electronic address: kelwkeel@uj.edu.sa.
² University of Jeddah, College of Science, Department of Chemistry, Jeddah, Saudi Arabia.
³ School of Nuclear Science and Technology, University of South China, Heng Yang 421001, PR China; Nuclear Materials Authority, El-Maadi, Cairo, P.O. Box 530, Egypt.

PMID: 37709221
DOI: 10.1016/j.ijbiomac.2023.126884

Abstract

The change of composition of an adsorbent material has been widely used as a method to increase its adsorption capacity, particularly concerning adsorbents made of polysaccharides. Introducing magnetic adsorbents into contaminated water treatment systems is a highly promising strategy, as it promotes the metal ions removal from water. Considering this, gum Arabic (GA) was associated with alginate (Alg), when magnetite nanoparticles were present or absent, to produce beads that were utilised to take up Cu(II), Cd(II), and Pb(II) from aqueous solution. After a complete characterisation (for which Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and swelling were used), the adsorption properties were established using batch and column tests. The magnetic beads (MAlg/GA) demonstrated improved adsorption in comparison with the beads made without magnetite (Alg/GA) under the same conditions. In normal adsorption conditions (pH 6.0, 25 °C, 2.5 g L^-1 of adsorbent dosage), the highest uptake capacities recorded for the MAlg/GA beads were: for Cu(II), 1.33 mmol g^-1; Cd(II), 1.59 mmol g^-1; and for Pb(II), 1.43 mmol g^-1. The pseudo-second-order kinetics and Langmuir isotherm models provided good fits for the adsorption of these metals. Overall, ion exchange and physical forces led to the uptake of these metals by both Alg/GA and MAlg/GA; moreover, the functional groups on the beads played crucial roles as binding sites. Additionally, it was observed that flow rates of >2 mL min^-1 did not produce noticeable changes in uptake levels over the same flow period. It was found that the efficient eluting agent was HNO₃ (0.2 M). In some cases, the metals were not removed fully from the used beads during the first five cycles of regeneration and reuse. The results of this investigation show that these beads are efficient adsorbents for the removal of metal ions from spiked well water samples.

Keywords: Flow rate; Gum Arabic-alginate; Heavy metal extraction; Polysaccharides; Well water.

MeSH terms

Adsorption
Alginates / chemistry
Cadmium / chemistry
Copper* / chemistry
Hydrogen-Ion Concentration
Ions
Kinetics
Lead
Magnetic Phenomena
Water Pollutants, Chemical* / chemistry

Substances

Copper
Cadmium
Alginates
Lead
Water Pollutants, Chemical
Ions