title: Adsorption of Pb(2+) ions on nanosized gamma-Fe(2)O(3): formation of surface ternary complexes on ligand complexation.
abstract: Adsorption of Pb(2+) ions on the combustion derived nanosized gamma-Fe(2)O(3) and its thiourea complex composite is reported. The adsorbents upon adsorption of Pb(2+) ions are characterised by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray microanalysis and infrared spectroscopy techniques. The eluent is characterised by atomic absorption spectroscopy for the estimation of Pb(2+) ions. The reduction in the amount of lead after adsorption was estimated to be around 50% in case of complex composite adsorbent and around 15% in case of the gamma-Fe(2)O(3) adsorbents. Orthorhombic PbSO(4) precipitated out from the eluent and is reported with a model reaction. Adsorption of lead onto the complex composite is explained through the formation of a surface tertiary complex. The advantage of employing a thiourea-gamma-Fe(2)O(3) complex composite as solid adsorbent for the adsorption of heavy metal pollutants is envisaged in the present investigation.
authors.affiliation: Department of Chemistry, Gulbarga University, Gulbarga 585106, India.
authors.forename: N N
authors.initials: NN
authors.lastname: Mallikarjuna
authors.forename: A
authors.initials: A
authors.lastname: Venkataraman