In order to elucidate the evolution mechanism of heavy metal species in landfill cells, three-dimensional excitation emission matrix fluorescence spectroscopy (3DEEM), fluorescence quenching titration and parallel factor analysis (PARAFAC) were employed to study the complexation process between Cu(Ⅱ) and colored dissolved organic matter (CDOM) from landfill with different ages. The experimental results indicated that the landfilled CDOM comprised protein-like, humic-like and fuvic-like matter. The relative content of protein-like matter decreased during the landfill process, whereas the humic-like and fuvic-like matter increased during the process. The range of the conditional stability constants and the percentage of fluorophores participated the complextion between Cu(Ⅱ) and protein-like matter with different ages were 4.00-5.75 and 22.78%-95.30%, respectively. Those parameters changed slightly for humic-like matter with different ages, which ranged from 4.71 to 5.54 and from 42.35% to 61.46%, respectively. As regard to fulvic-like matter, those parameters were 4.44-5.25 and 46.14%-57.22%, respectively. The complexation ability of humic-like substances with Cu(Ⅱ) decreased during the landfill process, though the percentage of fluorophores participated the complexation increased. The complexation ability of humic-like substances with Cu(Ⅱ) was stronger than that of fulvic-like matter, though the percentage of fluorophores participated the complexation in humic-like matter was low compared with fulvic-like matter.
Keywords: colored dissolved organic matter(CDOM); complexation; copper; municipal solid waste landfill; parallel factor(PARAFAC) analysis.