Selective Adsorption of Arsenic(V) lon by Use of Iron(III) Hydroxide-Loaded Coral Limestone

Abstract By use of iron(III) hydroxide-loaded coral limestone (abbreviated Fe-coral) as an adsorbent, a trace level of arsenic(V) ion in aqueous solution could be efficiently and selectively adsorbed onto the adsorbent surface. The arsenic adsorptibility of the Fe-coral depended upon the amount of iron(III) hydroxide loaded on the coral limestone. The arsenic adsorption was almost unaffected by the initial pH of the solution in the pH range 2–10, and was not practically influenced by the addition of such anions as chloride, nitrate, sulfate, perchlorate, and acetate in the aqueous solution. However, only coexisting phosphate caused a great depression in the arsenic adsorption. The arsenic absorbed onto Fe-coral was hardly desorbed in contact with an aqueous solution under a wide pH range (3.5–10). The arsenic adsorption was effectively applied to a column-type operation.