title: Kinetic modeling of adsorption of di-2-pyridylketone salicyloylhydrazone on silica gel.
abstract: The kinetics of DPKSH (di-2-pyridylketone salicyloylhydrazone) adsorption onto silica gel has been investigated at (25+/-1) degrees C and pH 1 and 4.7. The kinetics of adsorption of DPKSH is discussed using three kinetic models, the first-order Lagergren model, the pseudo-second-order model, and the intraparticle diffusion model. The adsorption of DPKSH, at pH 1 and 4.7, onto silica gel proceeds according to the pseudo-second-order model and the correlation coefficients were very close to 1. The intraparticle diffusion of DPKSH molecules within the silica gel particles was identified as the rate-limiting step. The parameters of the pseudo-second-order model are q(max,calc)=1.02 x 10(-4) and 1.5 x 10(-4) g DPKSH/g silica; k(2)=3.01 x 10(4) and 9.67 x 10(4) h(-1)g silica/g DPKSH, respectively, for pH 1 and 4.7.
authors.affiliation: Instituto de Química, Universidade de São Paulo, Caixa Postal 26077, CEP 05513-970, São Paulo, SP, Brazil.
authors.forename: P
authors.initials: P
authors.lastname: Antonio
authors.forename: K
authors.initials: K
authors.lastname: Iha
authors.forename: M E V
authors.initials: ME
authors.lastname: Suárez-Iha
mesh_terms: D000327:Adsorption; D006835:Hydrazones / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008956:Models, Chemical; D011725:Pyridines / Q000737:chemistry*; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D006835:Hydrazones; D011725:Pyridines; C518763:di-2-pyridylketone salicyloylhydrazone; D058428:Silica Gel; D012822:Silicon Dioxide