Sequential removal of phosphate and copper(II) ions using sustainable chitosan biosorbent

Fwu-Long Mi; Wen-Yi Chen; Zhi-Run Chen; I-Wen Chang; Shao-Jung Wu

doi:10.1016/j.ijbiomac.2024.131178

Sequential removal of phosphate and copper(II) ions using sustainable chitosan biosorbent

Int J Biol Macromol. 2024 Mar 28;266(Pt 1):131178. doi: 10.1016/j.ijbiomac.2024.131178. Online ahead of print.

Authors

Fwu-Long Mi¹, Wen-Yi Chen², Zhi-Run Chen², I-Wen Chang², Shao-Jung Wu³

Affiliations

¹ Department of Biochemistry and Molecular Cell Biology, School of Medicine, Taipei Medical University, Taipei 110, Taiwan; Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
² Department of Chemical Engineering, Ming Chi University of Technology, New Taipei City 243, Taiwan.
³ Department of Chemical Engineering, Ming Chi University of Technology, New Taipei City 243, Taiwan. Electronic address: sjwu@mail.mcut.edu.tw.

PMID: 38554905
DOI: 10.1016/j.ijbiomac.2024.131178

Abstract

Although adsorbents are good candidates for removing phosphorus and heavy metals from wastewater, the use of biosorbents for the sequential treatment of phosphorus and copper has not yet been studied. Porous chitosan (CS)-based biosorbents (CGBs) were developed to adsorb phytic acid (PA), a major form of organic phosphate. This first adsorbate (PA) further served as an additional ligand (P-type ligand) for the CGBs (N-type ligand) to form a complex with the second adsorbate (copper). After the adsorption of PA (the first adsorbate), the spent CGBs were recycled and used as a new adsorbent to adsorb Cu(II) ions (the second adsorbate), which was expected to have a dual coordination effect through P, N-ligand complexation with copper. The interactions and complexation between CS, PA and Cu(II) ions on the PA-adsorbed CGBs (PACGBs) were investigated by performing FTIR, XPS, XRD, and SEM-EDS analyses. The PACGBs exhibited fast and enhanced adsorption of Cu(II) ions, owing to the synergistic effect of the amino groups of CS (the original ligand, N-type) and the phosphate groups of PA (an additional ligand, P-type) on the adsorption of Cu(II) ions. This is the first time that sequential removal of phosphorus and heavy metals by biosorbents has been performed using biosorbents.

Keywords: Adsorption; Biosorbents; Chitosan; Copper; Heavy metals; Phosphate.