Combination of two-dimensional correlation spectroscopy and parallel factor analysis to characterize the binding of heavy metals with DOM in lake sediments.
Enhanced knowledge on the binding of heavy metal (HM) with dissolved organic matter (DOM) is essential for understanding the toxicity and migration of HMs. In this study, two-dimensional correlation spectroscopy (2D-COS) and parallel factor (PARAFAC) analysis were combined to characterize the metal binding properties of DOMs, which were respectively extracted from macrophyte- and algal-dominant sediments (named MDOM and ADOM) in a eutrophic shallow lake. 2D absorption COS revealed that MDOM exhibited more HM binding sites (193, 195, 196, 199, 201, 203, 205, 207, 208, 212, 217 nm) than ADOM (201, 205 nm). PARAFAC analysis identified one protein- and two humic-like components from all titrated samples, with each component exhibiting different binding behaviors. The modified Stern-Volmer model showed that PARAFAC-derived components in MDOM had higher conditional stability constants (logKM) than in ADOM, suggesting that macrophyte-dominant sediments might play a more important role in the detoxification of HMs. Meanwhile, low binding abilities of Zn(II)-DOM complexes indicated that the toxicity of zinc in eutrophic lakes should not be overlooked. More aromatic functional groups and binding sites were suggested to be responsible for the high binding ability. 2D-COS was a better approach than PARAFAC analysis for exploring HM-DOM interaction.
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China; State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Xianlin Campus, Nanjing University, Nanjing 210023, China.
Huacheng
H
Xu
Guanghui
G
Yu
Liuyan
L
Yang
Helong
H
Jiang
D001665:Binding Sites; D003300:Copper / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods; D005163:Factor Analysis, Statistical; D019015:Geologic Sediments / Q000032:analysis*; D006812:Humic Substances / Q000032:analysis; D007700:Kinetics; D060106:Lakes; D019216:Metals, Heavy / Q000032:analysis* / Q000737:chemistry; D011506:Proteins / Q000032:analysis; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D015032:Zinc / Q000737:chemistry
D006812:Humic Substances; D019216:Metals, Heavy; D011506:Proteins; D014874:Water Pollutants, Chemical; D003300:Copper; D015032:Zinc
Dissolved organic matter; Heavy metal; Lake sediments; Parallel factor (PARAFAC) analysis; Two-dimensional correlation spectroscopy (2D-COS)