Removal of arsenic and cadmium by akaganeite fixed-beds

The possibility of using a packed-bed (in column configuration) of akaganeite to remove oxyanions like As(V) and cations like Cd from aqueous solutions was the aim of the present study. Synthesized..akaganeite was used in two forms, i.e., in fine powder (of nanocrystals) and in the form of grains (as granular). The main examined parameters were: 1) the quantity of sorbent in the column and 2) the presence (or not) of ionic strength. The bed depth-service time (BDST) model was applied to the sorption results to model the column operation. The removal efficiency of As(V) anions by the sorptive column was found to be higher than that of Cd cations. The presence of increased ionic strength caused a serious increase of removal efficiency for the case of arsenic anions. Granular akaganeite was less effective in all cases, but still, it remained a good adsorbent.