Sulfur crosslinks from thermal degradation of chitosan dithiocarbamate derivatives and thermodynamic study for sorption of copper and cadmium from aqueous system

Soon Kong Yong, William M. Skinner, Nanthi S. Bolan, Enzo Lombi, Anitha Kunhikrishnan, Yong Sik Ok

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Pristine chitosan beads were modified with sulfur (S)-containing functional groups to produce thiolated chitosan beads (ETB), thereby increasing S donor ligands and crosslinks. The effect of temperature, heating time, carbon disulfide (CS2)/chitosan ratio, and pH on total S content of ETB was examined using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The total S content of ETB increased with increasing CS2/chitosan ratio and decreased with decreasing pH and increasing temperature (>60 °C) and heating time (at 60 °C). Spectroscopic analyses revealed the presence of thiol (–SH)/thione, disulfide (–S–S–), and sulfonate groups in ETB. The thiolation mechanism involves decomposition of dithiocarbamate groups, thereby forming thiourea crosslinks and trithiocarbonate, resulting in –SH oxidation to produce –S–S– crosslinks. The partially formed ETB crosslinks contribute to its acid stability and are thermodynamically feasible in adsorbing Cd and Cu. The S-containing functional groups added to chitinous wastes act as sorbents for metal remediation from acidic environments.

Original languageEnglish
Pages (from-to)1050-1059
Number of pages10
JournalEnvironmental Science and Pollution Research
Volume23
Issue number2
DOIs
Publication statusPublished - 2016 Jan 1
Externally publishedYes

Keywords

  • Chemisorption
  • Chitosan
  • Mercapto group
  • Oxidation
  • Soft Lewis base
  • Thioamide

ASJC Scopus subject areas

  • Environmental Chemistry
  • Pollution
  • Health, Toxicology and Mutagenesis

Fingerprint Dive into the research topics of 'Sulfur crosslinks from thermal degradation of chitosan dithiocarbamate derivatives and thermodynamic study for sorption of copper and cadmium from aqueous system'. Together they form a unique fingerprint.

  • Cite this