REDISTRIBUTION OF STRONTIUM DURING CRYSTALLIZATION OF AMORPHOUS FERRIHYDRITE TO GOETHITE

Sorption of strontium on an amorphous ferrihydrite has been studied un der a proceeding of its crystallization to goethite. Sorption fraction of strontium decreased from approximately 100% to 60% during the crys tallization. A sequential extraction technique was applied to study a degree of biding of strontium on the amorphous ferrihydrite and the cr ystalline geothite. Its result suggested that most of strontium sorbed on the iron(III) compounds was reversible form, but some amount of st rontium once sorbed on the amorphous ferrihydrite was transferred into an irreversible form on the crystalline geothite during the crystalli zation. The model calculation was carried out to study the redistribut ion behavior of strontium during the crystallization. From this calcul ation, it is likely that strontium sorbed on the amorphous ferrihydrit e was trapped into the crystalline geothite when the amorphous ferrihy drite was once dissolved to be crystallized to geothite.