Adsorption of Tungsten onto Zeolite Fly Ash Produced by Hydrothermally Treating Fly Ash in Alkaline Solution

作者：Ogata Fumihiko; Iwata Yuka; Kawasaki Naohito^*

来源：Chemical & Pharmaceutical Bulletin, 2014, 62(9): 892-897.

DOI：10.1248/cpb.c14-00291

• fly ash
• hydrothermally treated in an alkaline solution
• tungsten
• adsorption

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 20h. 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.

• 出版日期2014-9