title: Arsenic removal using hydrous nanostructure iron(III)-titanium(IV) binary mixed oxide from aqueous solution.
abstract: The synthetic bimetal iron(III)-titanium(IV) oxide (NHITO) used was characterized as hydrous and nanostructured mixed oxide, respectively, by the Föurier transform infra red (FTIR), X-ray diffraction (XRD) pattern and the transmission electron microscopic (TEM) image analyses. Removal of As(III) and As(V) using the NHITO was studied at pH 7.0 (+/-0.1) with variation of contact time, solute concentration and temperature. The kinetic sorption data, in general, for As(III) described the pseudo-first order while that for As(V) described the pseudo-second order equation. The Langmuir isotherm described the equilibrium data (303 (+/-1.6)K) of fit was well with the Langmuir model. The Langmuir capacity (q(m), mg g(-1)) value of the material is 85.0 (+/-4.0) and 14.0 (+/-0.5), respectively, for the reduced and oxidized species. The sorption reactions on NHITO were found to be endothermic and spontaneous, and took place with increasing entropy. The energy (kJ mol(-1)) of sorption for As(III) and As(V) estimated, respectively, is 9.09 (+/-0.01) and 13.51 (+/-0.04). The sorption percentage reduction of As(V) was significant while that of As(III) was insignificant in presence of phosphate and sulfate. The fixed bed NHITO column (5.1 cm x 1.0 cm) sorption tests gave 3.0, 0.7 and 4.5L treated water (As content < or = 0.01 mg L(-1)) from separate As(III) and As(V) spiked (0.35+/-0.02 mg L(-1)) natural water samples and from high arsenic (0.11+/-0.01 mg L(-1)) ground water, respectively when inflow rate was (0.06 L h(-1)).
authors.affiliation: Department of Chemistry, Presidency College, 86/1 College Street, Kolkata, West Bengal 700073, India.
authors.forename: Kaushik
authors.initials: K
authors.lastname: Gupta
authors.forename: Uday Chand
authors.initials: UC
authors.lastname: Ghosh
mesh_terms: D000327:Adsorption; D001151:Arsenic / Q000633:toxicity*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D010087:Oxides / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013431:Sulfates / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification / Q000379:methods; D014961:X-Ray Diffraction
chemical_list: D010087:Oxides; D010710:Phosphates; D013431:Sulfates; D014874:Water Pollutants, Chemical; D014025:Titanium; D007501:Iron; D001151:Arsenic