Environmental Engineering Reference
In-Depth Information
Problems
(1) Mention the ten key organic ligands of DOM that can complex trace metal ions.
(2) Mention the key DOM components that show fluorescence properties.
Explain the application of fluorescence properties to identify the complexa-
tion between metal ions (M) and DOM in aqueous media.
(3) Mention the DOM components of natural origin that can complex metal ions
in aqueous solution.
(4) Mention the key possible fluorophores in the molecular structures of fulvic
acid, humic acid, and tryptophan.
(5) Explain the theory of multisite Stern-Volmer equation for the determination
of M-DOM complexation.
(6) Explain the kinetics of the M-fulvic acid complexation regarding the binding
sites of fulvic acid.
(7) Derive the equation for the conditional stability constant of M-DOM com-
plexes in aqueous solution.
(8) How does SRFA behave as homogeneous and heterogeneous complexant to
trace metals?
(9) Explain the binding sites in fulvic acid and humic acid and how they differ
from autochthonous DOM and tryptophan.
(10) Explain the mechanism for the complexation of metal ions with DOM and
explain how the functional groups in tryptophan amino acid form complexes
with trace metal ions.
(11) Describe the effects of the M-DOM complexation that depend on the order
of complex formation of transition metals and other metals to DOM in natural
waters.
(12) Explain the electronic configuration of transition metals (Cu
2
+
and Cr
3
+
),
alkaline earths (Ca
2
+
), and heavy metals (Sb
3
+
) and how does it influence
the interaction with functional DOM groups in M-DOM complexation.
(13) Explain why transition metals generally have higher bonding properties with
DOM functional groups than alkali or alkaline earth metals.
(14) What are the controlling factors for the M-DOM complexation in aqueous
solution? Describe four important factors that can regulate the M-DOM
complexation in aqueous solution.
(15) Why are the fluorescence excitation-emission maxima shifted in metal-DOM
complexes? Explain the mechanisms.
(16) Explain the importance of M-DOM complexation in the aquatic
environment.
Acknowledgments
We thank Prof. Li Siliang of Institute of Geochemistry, Chinese Academy
of Sciences, China; Dr. Kazuhide Hayakawa of the Lake Biwa Environmental Research Institute,
Japan; and Dr. Youhei Yamashita of Hokkaido University, Japan for their constructive comments
and generous assistances. This work was financially supported by the Institute of Geochemistry, the
Chinese Academy of Sciences, Guiyang, China. This work was partly supported by Field Science
Education and Research Center, Kyoto University, Japan; University Turin, Italy; and Chinese
