Alginate-incorporated chitosan sorbent beads for effective remediation of heavy metal ion-contaminated aqueous media

Purpose The purpose of this study is to prepare alginate-mediated chitosan sorbent beads for the uptake of heavy metal ions of Cu(II), Ni(II) and Cr(III) from the aqueous media. Design/methodology/approach The chitosan-based beads were prepared using the sol–gel method and then characterised for surface morphology, elemental analysis, chemical functionality and crystalline and thermal properties using advanced analytical techniques. The metal ions’ adsorption capacity of the sorbent beads was measured using atomic absorption spectroscopy under various physicochemical conditions. Findings The native chitosan beads expressed the point of zero charge of 4.1, whereas the chitosan/alginate beads expressed it as 8.4. The results revealed that the equilibrium sorption capacity of the chitosan-based sorbents improved from 8.60 to 28.02 mg/L, 9.42 to 28.98 and 8.26 to 29.42 mg/L for Cu(II), Ni(II) and Cr(III) metal ions in the aqueous media, respectively. The experimental data were examined on the Langmuir and the Freundlich isotherms and found to fit with the R2 > 0.90. Practical implications Anthropogenic activities generate and dispose of heavy metal ions in water bodies, thus deteriorating the quality of aquatic life. The removal of such ions would improve the quality of water. Originality/value The prepared alginate-mediated chitosan beads could offer a sustainable solution for decontaminating heavy metal ions from polluted water.