http://www.eng.uwo.ca/research/grc/pdfs/2011/Boparai_et_al_Kinetics.pdf

Kinetics and thermodynamics of cadmium ion removal by adsorption onto nano zerovalent iron particles.

Fluoride removal from water by adsorption—A review

http://edge.rit.edu/content/P13418/public/Reference%20Documents/Fluoride%20Removal/Review%20of%20fluoride%20removal%20from%20drinking%20water.pdf

Review of fluoride removal from drinking water.

Fluoride in drinking water and defluoridation of water.

This paper demonstrates the synthesis of multi-wall carbon nanotubes and silica nanocomposite (CNT/SiO2). Successful realization of MWCNT/SiO2 nanostructure was observed by scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and high-resolution transmission electron microscopy studies. The as-prepared nanocomposite was evaluated as an adsorbent to remove lead, Pb(II), from aqueous solutions. The resulting MWCNT/SiO2 manifests propitious adsorption performance (~95%) over silica nanoparticles (~50%) and CNTs (~45%). Lagergren’s pseudo-first order, pseudo-second order and intraparticle diffusion models were used to analyse the kinetic data obtained at different initial Pb(II) concentrations. The adsorption kinetic data were described well by the pseudo-second order model with R2 of 0.99. The activation energy (Ea) of the adsorption process was calculated as 15.8 kJ mol−1. Adsorption data were described well by the Langmuir and Temkin models. Th...

Nanocomposite of carbon nanotubes/silica nanoparticles and their use for adsorption of Pb(II): from surface properties to sorption mechanism

This paper presents the synthesis of iron(III)−aluminum(III) mixed oxide with some of its physicochemical characteristics and fluoride adsorption behavior thereon. Results showed that the optimum i...

Adsorption of Fluoride from Aqueous Solution by a Synthetic Iron(III)−Aluminum(III) Mixed Oxide

Adsorption of fluoride by hydrous iron(III)-tin(IV) bimetal mixed oxide from the aqueous solutions

Fluoride removal efficiency from aqueous solution by synthetic iron(III)–aluminum(III)–chromium(III) ternary mixed oxide

Fluoride occurs in some drinking water sources at levels that are hazardous to health. Tests were conducted to assess the ability of a mineral-based adsorbent to take-up fluoride ion. Consequently, in search of novel adsorbent media, crystalline and hydrous iron(III)-zirconium(IV) hybrid oxide (IZHO) was synthesized, and tested to determine its capacity and kinetics for fluoride adsorption. The Fourier Transform Infrared (FTIR) spectrum of IZHO indicated the presence of Fe–O–Zr linkage which showed hybrid nature of the synthetic oxide. The optimum pH range for fluoride adsorption was ranged between 4.0 and 7.0. The analyses of the isotherm equilibrium data using the Langmuir and the Redlich–Peterson model equations by linear and non-linear methods showed that the data fitted better with latter model than the former. Thermodynamic analysis showed spontaneous nature of fluoride adsorption, and that took place with the increase of entropy. The kinetic data obtained for fluoride adsorption on IZHO at pH 6.8 (±0.1) and room temperature (303±2 K) described both the pseudo-first order and the reversible first-order equations equally well (r
 2= ∼0.98–0.99), and better than pseudo second order equation (r
 2= ∼0.96–0.98) for higher concentrations (12.5 and 25.0 mg/dm3) of fluoride. The kinetics of fluoride adsorption on the mixed oxide took place with boundary layer diffusion. External mass transport with intra-particle diffusion phenomena governed the rate limiting process, which has been confirmed from the Boyd poor non-linear kinetic plots.

Krishna Biswas

Papers

Adsorption of Fluoride from Aqueous Solution by a Synthetic Iron(III)−Aluminum(III) Mixed Oxide

Adsorption of fluoride by hydrous iron(III)-tin(IV) bimetal mixed oxide from the aqueous solutions

Fluoride removal efficiency from aqueous solution by synthetic iron(III)–aluminum(III)–chromium(III) ternary mixed oxide

Adsorption kinetics of fluoride on iron(III)-zirconium(IV) hybrid oxide

Agglomerated nanoparticles of hydrous Ce(IV) + Zr(IV) mixed oxide: Preparation, characterization and physicochemical aspects on fluoride adsorption