title: Calcined Mg-Fe-CO(3) LDH as an adsorbent for the removal of selenite.
abstract: Mg-Fe-CO(3) layered double hydroxide (LDH) with a Mg/Fe molar ratio of 2.0 was synthesized by co-precipitation method and its calcined product (CLDH) was obtained by heating Mg/Fe-LDH at 500 degrees C. Sorption of SeO(2-)(3) on CLDHs was studied and the results indicate that the sorption capacity of CLDHs was higher than that of uncalcined LDHs. Isotherms for SeO(2-)(3) sorption by CLDHs were well described using the Freundlich and Langmuir equations. The thermodynamic parameters, viz. DeltaG*, DeltaH*, DeltaS* were calculated to predict the nature of adsorption. The negative and positive values of DeltaG* and DeltaH* indicate that the adsorption process is spontaneous and endothermic in nature, respectively. The adsorption process followed first-order kinetics.
authors.affiliation: Institute of Minerals and Materials Technology (IMMT) (Formerly Regional Research Laboratory), Bhubaneswar 751 013, Orissa, India.
authors.forename: J
authors.initials: J
authors.lastname: Das
authors.forename: B
authors.initials: B
authors.lastname: Sairam Patra
authors.forename: N
authors.initials: N
authors.lastname: Baliarsingh
authors.forename: K M
authors.initials: KM
authors.lastname: Parida