Crayfish Carapace Powder Adsorbing Heavy Metal Ions from Aqueous Solution: Capacity, Characterization, Mechanism. Issue 1 (2nd January 2016) - Wang, Yuntao
ABSTRACT: Crayfish carapace powder is a low cost natural absorbent effective for the removal of heavy metals. Its adsorption capacity was far superior to its extracts—namely, chitin and chitosan. To understand the mechanism of heavy metals removed by this material, various techniques were implemented to characterize the samples. Scanning electron microscopy and X-ray diffraction analysis showed there was metal carbonate crystal formed on the surface of carapace granules after adsorbing heavy metal ions. The ion exchange between Ca 2+ and M 2+, chelation between M 2+ and chitin, protein, chemical precipitation, and physical adsorption may be the external mechanism of adsorption.