828
K. M. G. Mostofa et al.
degradation in seawater (Mostofa and Sakugawa 2009; Zhang et al. 2009;
Stedmon et al. 2007). The current works do not distinguish between the photoinduced, microbial and metal-complexation processing of the autochthonous DOM
and do not differentiate between e.g. autochthonous fulvic acids and terrestrial fulvic and humic acids. Such a differentiation and the elucidation of the behavior of
the single components should be a key focus for future research.
An increase in water temperature due to global warming may significantly alter
the biogeochemical functions in natural aquatic ecosystems. However, there is
currently no study that examines the temperature effect on the metal-complexation features of fluorescent DOM in waters, which might be another key issue for
future study. It may lead to understand the impacts of global warming on M-DOM
complexation in the aquatic environments.
Fluorescent whitening agents (FWAs) and household detergents show fluorescence properties and are widely distributed in the waters and sediments of rivers, lakes and oceans (Mostofa and Sakugawa 2009; Mostofa et al. 2005, 2010;
Managaki and Takada 2005; Stoll and Giger 1998; Poiger et al. 1999; Baker
2002; Yamaji et al. 2010). The complexation of trace elements with FWAs such as
diaminostilbene-type (DAS1) and distyryl biphenyl (DSBP) and household detergents might be an interesting concern for future research.
The stability constants for the formation of ternary complexes are similar to those of DOM in surface waters (Tables 1 and 2) (Khalil and Taha 2004;
Khalil and Fazary 2004; Radalla 2010; Rosas et al. 2010; Shiozawa et al. 2011).
Considering the similarity of the stability constants, ternary complex formation
should be taken into account in a speciation description of M-DOM complexation.
It could be vital to understand the high variability of stability constants in natural
waters and should be a focus for future research.
9 Nomenclature
CDOM Chromophoric dissolved organic matter
DOM
Dissolved organic matter
EDTA
Ethylenediaminetetraacetic acid
EHA
Elliot soil humic acid standard
EPS
Extracellular polymeric substances
FA
Fulvic acid
FDOM Fluorescent dissolved organic matter
HA
Humic acid
I
Ionic strength
Log 10 K Conditional stability constant (logarithm)
LFSE
Ligand field stabilization energy
LHA
Leonardite coal humic acid standard
SRFA
Suwannee River fulvic acid
SRHA
Suwannee River humic acid
K. M. G. Mostofa et al.
degradation in seawater (Mostofa and Sakugawa 2009; Zhang et al. 2009;
Stedmon et al. 2007). The current works do not distinguish between the photoinduced, microbial and metal-complexation processing of the autochthonous DOM
and do not differentiate between e.g. autochthonous fulvic acids and terrestrial fulvic and humic acids. Such a differentiation and the elucidation of the behavior of
the single components should be a key focus for future research.
An increase in water temperature due to global warming may significantly alter
the biogeochemical functions in natural aquatic ecosystems. However, there is
currently no study that examines the temperature effect on the metal-complexation features of fluorescent DOM in waters, which might be another key issue for
future study. It may lead to understand the impacts of global warming on M-DOM
complexation in the aquatic environments.
Fluorescent whitening agents (FWAs) and household detergents show fluorescence properties and are widely distributed in the waters and sediments of rivers, lakes and oceans (Mostofa and Sakugawa 2009; Mostofa et al. 2005, 2010;
Managaki and Takada 2005; Stoll and Giger 1998; Poiger et al. 1999; Baker
2002; Yamaji et al. 2010). The complexation of trace elements with FWAs such as
diaminostilbene-type (DAS1) and distyryl biphenyl (DSBP) and household detergents might be an interesting concern for future research.
The stability constants for the formation of ternary complexes are similar to those of DOM in surface waters (Tables 1 and 2) (Khalil and Taha 2004;
Khalil and Fazary 2004; Radalla 2010; Rosas et al. 2010; Shiozawa et al. 2011).
Considering the similarity of the stability constants, ternary complex formation
should be taken into account in a speciation description of M-DOM complexation.
It could be vital to understand the high variability of stability constants in natural
waters and should be a focus for future research.
9 Nomenclature
CDOM Chromophoric dissolved organic matter
DOM
Dissolved organic matter
EDTA
Ethylenediaminetetraacetic acid
EHA
Elliot soil humic acid standard
EPS
Extracellular polymeric substances
FA
Fulvic acid
FDOM Fluorescent dissolved organic matter
HA
Humic acid
I
Ionic strength
Log 10 K Conditional stability constant (logarithm)
LFSE
Ligand field stabilization energy
LHA
Leonardite coal humic acid standard
SRFA
Suwannee River fulvic acid
SRHA
Suwannee River humic acid