Synthesis and applications of eco-magnetic nano-hydroxyapatite chitosan composite for enhanced fluoride sorption

• Published in: Carbohydrate polymers 2015-12, Vol.134, p.732-739
• Main Authors: Pandi, Kalimuthu, Viswanathan, Natrayasamy
• Format: Article
• Language: English
• Subjects: Adsorption; Chemistry Techniques, Synthetic; Chitosan; Chitosan - chemistry; Composite; Durapatite - chemistry; Eco-magnetic; Fluoride; Fluorides - chemistry; Fluorides - isolation & purification; Kinetics; Magnetite Nanoparticles - chemistry; Nano-hydroxyapatite; Nanocomposites - chemistry; Sorption; Thermodynamics; Water - chemistry; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - isolation & purification
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2015.08.003

•Defluoridation study was carried out using eco-magnetic Fe3O4@n-HApCS composite.•Fe3O4@n-HApCS composite possesses higher defluoridation capacity (DC) than individual components.•In field studies, the composite reduce fluoride concentration below the tolerance limit.•Fe3O4@n-HApCS composite can easily recover and separate by external magnetic field. Adsorption is a significant reaction occurs between adsorbent/water interface for controlling the pollutants in the aqueous environment. In this regard, an eco-magnetic biosorbent was prepared by uniform deposition of magnetic Fe3O4 particles on the surface of nano-hydroxyapatite (n-HAp)/chitosan (CS) nanocomposite namely Fe3O4@n-HApCS composite as versatile sorbent for fluoride sorption. The resulting Fe3O4@n-HApCS nanocomposite was characterized by FTIR and SEM with EDAX techniques. The defluoridation capacity (DC) was found to depend on the contact time, pH, co-existing anions, initial fluoride concentration and temperature. The sorption isotherm was investigated by Freundlich, Langmuir and Temkin isotherm models using the batch method. The thermodynamic parameters revealed the feasibility, spontaneity and endothermic nature of fluoride sorption. The results of this research work designated that Fe3O4@n-HApCS composite having the excellent defluoridation capacity than the individual components and interesting to note that the easy magnetic separation of Fe3O4@n-HApCS composite from aqueous medium.