title: Adsorption of di-2-pyridyl ketone salicyloylhydrazone on Amberlite XAD-2 and XAD-7 resins: characteristics and isotherms.
abstract: The adsorption of DPKSH onto Amberlite XAD-2 (styrene resin) and XAD-7 (acrylic ester resin) has been investigated, at (25+/-1) degrees C and pH 4.7. The experimental equilibrium data were fitted to the Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) models. These three models provide a very good fit for both resins and the respective constants KL, KF, and KDR were calculated. For the same DPKSH concentration interval, the minimum time of contact for adsorption maximum at XAD-7 was smaller than at XAD-2 and the maximum amount of DPKSH adsorbed per gram of XAD-2 is smaller than at XAD-7. The investigation indicates that the mean sorption energy (E) characterizes a physical adsorption and the surfaces of both resins are energetically heterogeneous. The constants obtained in these studied systems were correlated and compared with those obtained for the silica gel/DPKSH system.
authors.affiliation: Instituto de Química, Universidade de São Paulo, Caixa Postal 26077, CEP 05513-970, São Paulo, Brazil.
authors.forename: P A M
authors.initials: PA
authors.lastname: Freitas
authors.forename: K
authors.initials: K
authors.lastname: Iha
authors.forename: M C F C
authors.initials: MC
authors.lastname: Felinto
authors.forename: M E V
authors.initials: ME
authors.lastname: Suárez-Iha
mesh_terms: D000327:Adsorption; D002627:Chemistry, Physical / Q000379:methods; D003102:Colloids / Q000737:chemistry*; D005782:Gels; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008422:Materials Testing; D008956:Models, Chemical; D011137:Polystyrenes / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry*; D012117:Resins, Synthetic / Q000737:chemistry*; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
chemical_list: D003102:Colloids; D005782:Gels; D011137:Polystyrenes; D011145:Polyvinyls; D012117:Resins, Synthetic; C012101:XAD-4 resin; D058428:Silica Gel; D012822:Silicon Dioxide; C003771:Amberlite XAD-2 resin; C046797:amberlite