caa a22 4500 463170342 CHVBK 20180406164811.0 cr unu---uuuuu 170326e20070201xx s 000 0 eng 10.1007/s10450-007-9000-1 doi (NATIONALLICENCE)springer-10.1007/s10450-007-9000-1 Adsorption kinetics of fluoride on iron(III)-zirconium(IV) hybrid oxide [Elektronische Daten] [Krishna Biswas, Durjoy Bandhoyapadhyay, Uday Ghosh] 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±2K) 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 25.0mg/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. Springer Science+Business Media, LLC, 2007 Adsorption nationallicence Fluoride nationallicence Kinetics nationallicence Isotherm nationallicence Iron(III)-zirconium(IV) oxide nationallicence C i : The initial concentration (mg/dm3) of fluoride in solution nationallicence C e : The concentration of fluoride (mg/dm3) in solution at equilibrium nationallicence C a : The concentration of fluoride (mg/dm3) in solution at any time, t nationallicence C b : The concentration of fluoride in solid phase (mg/g) at any time, t nationallicence C a 0 : The initial concentration of fluoride in solution (mg/dm3) nationallicence C b 0 : The initial concentration of fluoride in adsorbent phase (mg/g) nationallicence Cae : The equilibrium concentration of solute in solution (mg/dm3) nationallicence q e : The adsorption capacity (mg/g) at equilibrium nationallicence q m : The monolayer adsorption capacity (mg/g) nationallicence q t : The adsorption capacity (mg/g) at any time, t nationallicence B L : The Langmuir adsorption equilibrium constant (dm3/mg) nationallicence A L : The Langmuir constant (dm3/g) nationallicence A RP : The Redlich-Peterson model isotherm constant (dm3/g) nationallicence B RP : The Redlich-Peterson model isotherm constant (dm3/mg) RP n nationallicence n RP : The Redlich-Peterson isotherm model exponent nationallicence k 1 : The pseudo-first order rate constant (time−1) nationallicence k 2 : The pseudo-second order rate constant (mg/g time) nationallicence t : time (min) nationallicence Xa : The fractional conversion of solute nationallicence k # : (=k 1+k 2) the overall rate constant (time−1) nationallicence k 1 : The rate of forward reaction (time−1) nationallicence k 2 : The rate of backward reaction (time−1) nationallicence k B : (=−k #) the rate constant (time−1) of Bhattacharya and Venkobachar model kinetics nationallicence R L : The equilibrium parameter nationallicence Δ G 0 : The Gibbs free energy change (kJ/mol) nationallicence Δ H 0 : The enthalpy change (kJ/mol) nationallicence Δ S 0 : The entropy change (kJ/mol/K) nationallicence R : The universal gas constant (8.314 J/mol/K) nationallicence T : The absolute temperature (K) nationallicence D f : The film diffusion coefficient (cm2/s) nationallicence D p : The pore diffusion coefficient (cm2/s) nationallicence r 0 : The mean radius (cm) of particles nationallicence k i : The diffusion rate constant (mg/g min0.5) nationallicence F : The fraction of solute adsorbed nationallicence Bt : A mathematical function of F nationallicence C L : Liquid phase equilibrium concentration of adsorbate (mg/dm3) nationallicence C s : Solid phase adsorbate concentration at equilibrium (mg/g) nationallicence Biswas Krishna Department of Chemistry, Presidency College, 86/1 College Street, 700073, Kolkata, India aut Bandhoyapadhyay Durjoy Department of Chemistry, Presidency College, 86/1 College Street, 700073, Kolkata, India aut Ghosh Uday Department of Chemistry, Presidency College, 86/1 College Street, 700073, Kolkata, India aut Adsorption Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 13/1(2007-02-01), 83-94 0929-5607 13:1<83 2007 13 10450 https://doi.org/10.1007/s10450-007-9000-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10450-007-9000-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Biswas Krishna Department of Chemistry, Presidency College, 86/1 College Street, 700073, Kolkata, India aut NATIONALLICENCE 700 1- Bandhoyapadhyay Durjoy Department of Chemistry, Presidency College, 86/1 College Street, 700073, Kolkata, India aut NATIONALLICENCE 700 1- Ghosh Uday Department of Chemistry, Presidency College, 86/1 College Street, 700073, Kolkata, India aut NATIONALLICENCE 773 0- Adsorption Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 13/1(2007-02-01), 83-94 0929-5607 13:1<83 2007 13 10450 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer