title: Removal of fluoride from water using iron oxide-hydroxide nanoparticles.
abstract: A novel and facile method for the synthesis of uniform stoichiometric powder form of non-magnetic iron oxide-hydroxide nanoparticles with spherical morphology and its application for defluoridation of drinking water is reported. X-ray powder diffraction analysis (XRD), BET surface area, FTIR, field emission scanning electron microscopy (FESEM) and Transmission electron microscopy (TEM) images were used to characterize nanoscale iron oxide-hydroxide. Transmission electron microscopy (TEM) image revealed the formation of iron oxide-hydroxide nanoparticles with spherical morphology. The iron oxide-hydroxide nanoparticles showed an excellent ability to remove fluoride (F-) from contaminated water over a wide range of pH. The influences of temperature, stirring speed, pH, adsorbent dose and contact time were studied. The equilibrium data were tested with various isotherm models and finally, a calculation procedure was reported for the calculation of adsorbent requirement. The fluoride adsorbed nanoparticles was regenerated upto 70% using sodium hydroxide or hydrochloric acid solution. The iron oxide-hydroxide nanoparticles can be used as an effective and replicable adsorbent media for defluoridation of water in presence of competing anions like chloride, iodate, iodide and sulphate.
authors.affiliation: Defence Research Laboratory, Post Bag No. 2, Tezpur 784001, Assam, India.
authors.forename: Prasanta Kumar
authors.initials: PK
authors.lastname: Raul
authors.forename: Rashmi Rekha
authors.initials: RR
authors.lastname: Devi
authors.forename: Iohborlang M
authors.initials: IM
authors.lastname: Umlong
authors.forename: Saumen
authors.initials: S
authors.lastname: Banerjee
authors.forename: Lokendra
authors.initials: L
authors.lastname: Singh
authors.forename: Mihir
authors.initials: M
authors.lastname: Purkait