Because seashells, which are a waste product in the seafood industry, are not recycled, several studies have investigated effective uses for discarded shells. Herein we report the Cd
2+ ion adsorption performances of ground scallop and pearl shells. The effects of the specific surface area and the crystallite size on the adsorption capacities of Cd
2+ ions were estimated. We found that ground seashells have potential to adsorb Cd
2+ ions.
We measured the removal ratio of Cd
2+ ions using ground shell particles with close to the same specific surface area. The removal ratio of the pearl shells(aragonite form, 9.0 m
2/g)and the scallop shells(calcite form, 12.3 m
2/g)was 84 % and 23 %, respectively. The pearl shells with low crystallite size exhibited excellent adsorption performance compared to the scallop shells and reagent calcium carbonate. When the aragonite particles were immersed in aqueous solutions including Cd
2+ ions, the ions were easily fixed as cadmium carbonate. On the other hand, the adsorbed amount was positively correlated with the specific surface area of the calcite particles. The adsorbed amount of Cd
2+ ions for aragonite and calcite shell particles depended strongly on the crystallinity and the specific surface area of shells, respectively.
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