among differentsize ferrihydrite fractions as adsorbed and dissolved Zn (Table 1). Thus, the difference in the Zn concentration between the and (i i + 1)th fractions, C Zn,i − C Zn,i+1, was thought to be the concentration of Zn adsorbed on ferrihydrite aggregates having the corresponding size range. In the similar way to the ferrihydrite ...