Defluoridation of water by Tea-bag model using La³⁺ modified synthetic resin@chitosan biocomposite

The aim of this work is to gain a better understanding of the formation of lanthanum complex onto iminodiacetic acid and chitosan (CS@La-IDAMP) composite for effective removal of fluoride from aqueous solution using a tea-bag model for the first time. The surface textural and chemical properties of the synthesized composites were characterized by FTIR, SEM with EDAX and mapping images. The experimental data revealed that the fluoride adsorption was rapid, maximum fluoride removal could be removed within 12 min contact time at neutral pH in room temperature under batch equilibrium model. The equilibrium data for adsorption of fluoride on the synthesized blends were well represented by the Freundlich isotherm, giving a maximum adsorption capacity of 17.50 mg/g. The adsorption kinetic models were also examined and it was found that all the sorption processes were better described by the pseudo-second-order model. This results suggested that the efficiency of the fluoride removal process was mainly controlled by electrostatic attraction and ion-exchange mechanism. Furthermore, the CS@La-IDAMP material was tested for the regeneration ability with the suitable regenerant to make this process as cost-effective. Finally, it can be concluded that the composite material is the potential adsorbent for the treatment of fluoride from water.