title: Adsorption of tungsten onto zeolite fly ash produced by hydrothermally treating fly ash in alkaline solution.
abstract: Fly ash (FA) was hydrothermally treated in an alkaline solution to produce zeolite fly ash (Z-FA). The properties of the FA and Z-FA were investigated. The amounts of tungsten (W) adsorbed onto the FA and Z-FA surfaces were evaluated. Z-FA was produced by hydrothermally treating FA in an alkaline solution. The specific surface area and pore volume of the Z-FA were greater than those of the FA. More W was adsorbed onto the Z-FA surface than onto the FA surface. The adsorption isotherms for W were fitted using both the Freundlich and Langmuir equations. The equilibrium concentrations of W adsorbed onto the FA and Z-FA surfaces were subsequently reached within 20 h. The pseudo-second-order model more accurately described the data than did the pseudo-first-order model. Sodium hydroxide solutions (1-50 mmol/L) were used to easily recover W from Z-FA, indicating that Z-FA was useful for recovering W from aqueous solutions.
authors.affiliation: Faculty of Pharmacy, Kinki University.
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Ogata
authors.forename: Yuka
authors.initials: Y
authors.lastname: Iwata
authors.forename: Naohito
authors.initials: N
authors.lastname: Kawasaki
mesh_terms: D000327:Adsorption; D000468:Alkalies / Q000737:chemistry*; D060729:Coal Ash; D006863:Hydrogen-Ion Concentration; D012972:Sodium Hydroxide / Q000737:chemistry*; D013816:Thermodynamics; D014414:Tungsten / Q000737:chemistry*; D017641:Zeolites / Q000737:chemistry*
chemical_list: D000468:Alkalies; D060729:Coal Ash; D017641:Zeolites; D012972:Sodium Hydroxide; D014414:Tungsten