ORIGINAL ARTICLES   

Minerva Biotecnologica 2016 June;28(2):75-80

Copyright © 2016 EDIZIONI MINERVA MEDICA

lingua: Inglese

Non-cross-linked membrane and beads of chitosan for efficient heavy metal removal

Masih KARIMI ALAVIJEH ¹, Fardin MOUMIVAND ¹, Akram ZAMANI ^{1, 2}, Keikhosro KARIMI ^{1, 2}

¹ Department of Chemical Engineering, Isfahan University of Technology, Isfahan, Iran; ² Industrial Biotechnology Group Institute for Biotechnology and Bioengineering, Isfahan University of Technology, Isfahan, Iran

BACKGROUND: The objective of this study was preparation of non-crosslinked beads and membrane of chitosan and their application for removal of heavy metals from aqueous solutions.
METHODS: An acetic acid processing was employed for preparation of the membrane and beads of chitosan. Then they were used for removal of Fe3+, Pb2+, and Cd2+ with low concentration of 15, 12, and 16 ppm, respectively. The chitosan beads were also subjected to a process of 12 subsequent biosorption cycles which were performed for 20 min in fresh heavy metal solutions.
RESULTS AND CONCLUSIONS: The results showed that Fe3+ and Pb2+ were rapidly removed from the solution, and their removal capacities were higher than that of Cd2+ by both type of the prepared chitosan forms. Using the membrane and beads about 99% of Fe3+ and Pb2+ and 20% of Cd2+ were eliminated from the metal solution after 20 min. Pseudo-second order model described the kinetics of Pb2+ and Fe3+ adsorptions very well. In contrast, intraparticle diffusion model predicted the kinetics of Cd2+ removal with a high accuracy. The beads exhibited 93±0, 55±3, and 37±4 % of their Pb2+ and Fe3+ removal efficiencies after 4th, 6th, and 9th cycles, respectively. However, the beads could not adsorb Pb2+ and Fe3+ in 10-12th cycles, instead they released a part of the adsorbed metals during these cycles.