XAFS study of Cu sorption products on smectites treated with alpha-amino acids

The interaction between Cu-exchanged smectites with different layer charge, a montmorillonite and a beidellite, and .alpha.-amino acids, glycine and cysteine, was studied. Sequential extn. procedures were carried out in order to test the possibility of removing metals from the mineral structure. Cu sorption is dominated by cation exchange, whereas after the amino acid treatment, Cu-amino acid-smectite complexes occupy the interlayer positions. The formation of a stable chelate complex with .alpha.-amino acids permits Cu to be resistant to migration in soils and groundwaters. X-ray absorption spectroscopy was used to define the local environment of Cu taken up by smectites.