Efficient removal of low concentrations of copper and lead ions in water using chitosan-condensed tannin composite microspheres

• Published in: INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
• Main Authors: Wang, Liang; Chen, Xinyi; Xi, Xuedong; Lee, Seng Hua; Lum, Wei Chen; Huang, Yuxiang; Du, Guanben; Zhou, Xiaojian; Zhang, Jun
• Format: Article
• Language: English
• Published: ELSEVIER 2024
• Subjects: Biochemistry & Molecular Biology; Chemistry; Polymer Science
• Online Access: https://www-webofscience-com.uitm.idm.oclc.org/wos/woscc/full-record/WOS:001359183200001
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2024.137438

Condensed tannin was solidified onto chitosan microspheres to prepare chitosan-tannin (CT) composite micro- spheres with a simple preparation method to study its performance in adsorbing copper (Cu2+) and lead ions (Pb2+) in aqueous media. The study investigated the influence of the mass ratio of tannin and chitosan, pH value, adsorption time, and initial concentrations of Cu2+ and Pb2+ on the adsorption capacity of Cu2+ and Pb2+ ions. Additionally, the study examined the adsorption isotherms and kinetics of Cu2+ and Pb2+ on CT composite microspheres. The adsorption process aligns more closely with the fitting results of the Langmuir model. The maximum capacity for saturated monolayer adsorption of CT composite microspheres for Cu2+ and Pb2+ was 37.6 and 52.9 mg/g, respectively. The adsorption process of CT composite microspheres for Cu2+ and Pb2+ was primarily driven by single-layer chemical adsorption. In addition, metal ions adsorbed onto CT composite microspheres can be released by treating them with a dilute solution of strong acid. Furthermore, the CT composite microspheres exhibited impressive removal efficiencies of 82 % and 95 % for Cu2+ and Pb2+ respectively, even at low concentrations of 2 mg/L. The CT composite microspheres have the ability to easily separate the adsorbed Cu2+ and Pb2+ ions.