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 Author: Wang L.; Chen X.; Xi X.; Lee S.H.; Lum W.C.; Huang Y.; Du G.; Zhou X.; Zhang J.
• Format: Article
• Language: English
• Published: Elsevier B.V. 2024
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85209078846&doi=10.1016%2fj.ijbiomac.2024.137438&partnerID=40&md5=ed0ea532385ff4f207b114e7d1303196

Condensed tannin was solidified onto chitosan microspheres to prepare chitosan-tannin (CT) composite microspheres 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. © 2024 Elsevier B.V.