Environmental Engineering Reference
In-Depth Information
et al.
2004
; Yamashita and Tanoue
2004
,
2008
; Wada et al.
2007
; Hanamachi et al.
2008
; Ortega-Retuerta et al.
2009
; Aoki et al.
2008
; Biddanda and Benner
1997
;
Hulatt et al.
2009
; Bertilsson and Jones
2003
; Chen and Gardner
2004
; Stedmon
and Markager
2005a
; Stedmon et al.
2007a
,
b
; Wetz and Wheeler
2007
; Zhao et al.
2009
).
Re-suspension of algae or phytoplankton in ultrapure water (Milli-Q), arti-
ficial sea water and natural waters can release new organic compounds, either
under irradiation or under dark incubation. These organic substances, produced
either under irradiation (Fig.
1
a) or in the dark (Fig.
1
b, c) show fluorescence
(excitation-emission matrix, EEM) properties. The EEM spectra of autochtho-
nous DOM (Fig.
1
a, b) are roughly similar to those of allochthonous fulvic acid
and show two fluorescence peaks at peak C- and A-regions (Fig.
1
d). In contrast,
they are different from allochthonous humic acids that show more than two peaks
at peak C-region (Fig.
1
f). Based on the similarities of the EEM spectra, the key
component of autochthonous fluorescent DOM is defined as “autochthonous ful-
vic acid (C-like)” of algal or phytoplankton origin. The other component (Fig.
1
c)
is defined as “autochthonous fulvic acid (M-like)” of algal or phytoplankton ori-
gin, based on the similarities with the marine humic-like component (Coble
1996
,
2007
). Identification of autochthonous DOM of algal or phytoplankton origin is
(a)
(b)
(c)
Peak A
Peak C
Peak C
Peak A
Peak M
(d)
(e)
Peak C
Peak A
Peak C
Peak M
Peak A
Ex wavelength (nm)
Fig. 1
Comparison of the fluorescent components of autochthonous fulvic acid (C-like) pro-
duced under microbial respiration of lake algae (
a
), autochthonous fulvic acid (C-like) under
photorespiration or assimilation of algal biomass (
b
) and autochthonous fulvic acid (M-like)
under microbial respiration of algae (
c
) with aqueous samples of standard Suwannee River Ful-
vic Acid (
d
) and Suwannee River Humic Acid (
e
) identified using PARAFAC modeling on the
EEM spectra of their respective samples.
Data source
Mostofa KMG et al., (unpublished data)
