Combination of two-dimensional correlation spectroscopy and parallel factor analysis to characterize the binding of heavy metals with DOM in lake sediments

- MDOM exhibited more HM binding sites than ADOM.
- PARAFAC-derived components in MDOM had higher log KM values than those in ADOM.
- Cu(II) exhibited stronger binding capacity than Zn(II) for both MDOM and ADOM.
- More aromatic functional groups and binding sites accounted for high binding capacity.
- 2D-COS was a better approach than PARAFAC analysis for exploring HM-DOM interaction.