A Novel Chitosan/Nano-Hydroxyapatite Composite for the Adsorptive Removal of Cd(II) from Aqueous Solution.

Content Provider	Europe PMC
Author	El Kaim Billah, Rachid Ayouch, Ikrame Abdellaoui, Youness Kassab, Zineb Khan, Moonis Ali Agunaou, Mahfoud Soufiane, Abdessadik Otero, Marta Jeon, Byong-Hun
Editor	Böker, Alexander Predoi, Daniela
Copyright Year	2023
Abstract	A novel polymer bio-composite based on nano-hydroxyapatite (n-Hap) and chitosan (CS) (CS/n-Hap) was synthesized to effectively address toxic cadmium ions removal from water. The composition and structure of CS/n-Hap bio-composite were analyzed through different characterization techniques. XRD patterns affirmed that the crystalline structure of n-Hap remained unaltered during CS/n-Hap synthesis, while FT-IR spectrum sustained all the characteristic peaks of both CS and n-Hap, affirming the successful synthesis of CS/n-Hap. Adsorption studies, including pH, adsorbent dosage, contact time, initial Cd(II) concentration, and temperature, were carried out to explain and understand the adsorption mechanism. Comparatively, CS/n-Hap bio-composite exhibited better Cd(II) adsorption capacity than pristine CS, with an experimental maximum uptake of 126.65 mg/g under optimized conditions. In addition, the kinetic data were well fitted to the pseudo-second-order model, indicating the formation of chemical bonds between Cd(II) and CS/n-Hap during adsorption. Furthermore, the thermodynamic study suggested that Cd(II) adsorption onto CS/n-Hap was endothermic and spontaneous. The regeneration study showed only about a 3% loss in Cd(II) uptake by CS/n-Hap after five consecutive cycles. Thus, a simple and facile approach was here developed to synthesize an eco-friendly and cost-effective material that can be successfully employed for the removal of toxic heavy metal ions from water.
Journal	Polymers
Volume Number	15
PubMed Central reference number	PMC10058910
Issue Number	6
PubMed reference number	36987304
e-ISSN	20734360
DOI	10.3390/polym15061524
Language	English
Publisher	MDPI
Publisher Date	2023-03-19
Access Restriction	Open
Rights License	Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). © 2023 by the authors.
Subject Keyword	nano-hydroxyapatite chitosan bio-composite cadmium adsorption mechanism
Content Type	Text
Resource Type	Article
Subject	Chemistry Polymers and Plastics