Adsorption of Pb2+, Cu2+ and Cd2+ by sulfhydryl modified chitosan beads

Yuru Yang; Lei Zeng; Zongkun Lin; Huabin Jiang; Aiping Zhang

doi:10.1016/j.carbpol.2021.118622

Adsorption of Pb²⁺, Cu²⁺ and Cd²⁺ by sulfhydryl modified chitosan beads

Carbohydr Polym. 2021 Nov 15:274:118622. doi: 10.1016/j.carbpol.2021.118622. Epub 2021 Sep 1.

Authors

Yuru Yang¹, Lei Zeng¹, Zongkun Lin¹, Huabin Jiang¹, Aiping Zhang²

Affiliations

¹ Institute of Biomass Engineering, South China Agricultural University, Guangzhou 510642, P.R. China.
² Institute of Biomass Engineering, South China Agricultural University, Guangzhou 510642, P.R. China. Electronic address: aiping@scau.edu.cn.

PMID: 34702451
DOI: 10.1016/j.carbpol.2021.118622

Abstract

A chitosan-based bead was synthesized by crosslinking as well as sulfhydryl modification reaction and its removal ability of Pb²⁺, Cu²⁺ and Cd²⁺ was investigated. The test results showed that the crystal structure of chitosan was destroyed completely and the specific surface area was greatly increased after modification. The adsorption of Pb^{2+, Cu2+ and Cd2+ by the beads was} carried out at different pH, ionic strength, contact time and initial concentration and the maximum adsorption capacities were 273.7 mg/g, 163.3 mg/g and 183.1 mg/g, respectively. Furthermore, due to the large ion radius of Pb²⁺, its adsorption was seriously disturbed by other ions in the competitive adsorption process. Finally, the adsorption processes of Pb²⁺, Cu²⁺ and Cd²⁺ were well fitted by the Langmuir isotherm model and the pseudo second-order kinetics model, respectively. Combined with the results of X-ray photoelectron spectroscopy, chemical coordination is the main adsorption mechanism.

Keywords: Adsorption; Chitosan; Heavy metal ions; Kinetics and isotherms; Meso-23-dimercaptosuccinic acid.