Environmental Engineering Reference
In-Depth Information
2011
). Note that Standard HAs of Elliot Soil have
δ
13
C
=
−
22.6 ‰; Pahikee peat
have
δ
13
C
=
−
26.0 ‰, and Leonardite have
δ
13
C
=
−
23.8 ‰. Reference HAs
of Suwannee River have
δ
13
C
=
−
28.2 ‰, Pahikee peat have
δ
13
C
=
−
26.3 ‰,
Nordic Lake have
δ
13
C
=
−
27.8 ‰, and Summit Hill soil have
δ
13
C
=
−
26.3 ‰
(IHSS
2011
). In addition, carbon isotope composition of dissolved humic and ful-
vic acids shows that the
Δ
14
C values are ranged from
−
247 to
+
26 ‰ whilst the
average values are
−
170
±
79 ‰ for humic acid and
−
44
±
73 ‰ for fulvic
acid (Nagao et al.
2011
). This suggests that the residence time of fulvic acid in the
watershed is being shorter than that of humic acid (Nagao et al.
2011
).
4.1.3 Definition of Autochthonous Fulvic Acids and Chemical
Nature of Autochthonous DOM
The key autochthonously produced biochemical organic groups or substances
(Mostofa et al.
2009a
) identified in natural waters can be classified as: autoch-
thonous fulvic acids (C-like and M-like) of algal (cyanobacteriam) or phy-
toplankton origin; carbohydrates such as uranic acids, amino sugars and
neutral sugars including free mono-, oligo-. lipopoly-, exopoly-, homopoly-, and
heteropolysaccharides; nitrogen-containing organic compounds including amino
acids, proteins, amines, amides, urea, purines, pyrimidines, peptides, polypep-
tides, pyrrole, and indole; lipids, including saturated, monounsaturated, polyun-
saturated, branched-chain and odd-chain fatty acids (mostly composed of oleic
acid, arachidonic acid, eicosapentanoic acid, linoleic acid, docosahexaenoic acid,
cis-vaccenic acid, iso- and anteiso-C
15
and C
17
fatty acids, polyunsaturated C
22
and C
20
fatty acids, high molecular-weight, straight-chain (C
24
, C
26
, C
28
,C
30
)
fatty acids; organic acids including mono-, di- and tri-carboxylic acids, glycol-
late, and hydroxamate; allelopathic compounds. There are also steroidal alcohols
(sterols) such as 24-methyl-cholesta-5,24(28)-dien-3
ß
-ol, 24-ethylcholest-5-en-
3
ß
-ol, cholesta-5,22
E
-dien-3
ß
-ol, cholest-5-en-3
ß
-ol, cholesta-5,22-dien-3
ß
-ol,
27-Nor-24-methylcholesta-5,22-dien-3
ß
-ol, 4
α
,23,24-trimethyl-5
α
-cholest-22
E
-
en-3
ß
-ol (dinosterol), 24-methylcholesta-5,22-dien-3
ß
-ol, 24-ethylcholesta-5,22
E
-
dien-3
ß
-ol, 24-ethylcholesta-5-en-3
ß
-ol, 24-ethylcholesta-5,24(28)
E
-dien-3
ß
-ol,
24-n-propylcholesta-5,24(28)
E
-dien-3
ß
-ol, 3-methyllidene-7,11,15-trimethylhexa-
decan-1,2-diol (phytyldiol); vanillyl and syringyl phenols including vanillin, ace-
tovanillone, vanillic acid, syringaldehyde, acetosyringone and syringic acid from
lignin-derived oxidation products; bisnorhopane and various alkenones such as
four polyunsaturated C
37
and C
38
methyl- and ethyl- alkenones, 6,10,14-trimeth-
ylpentadecan-2-one; pigments including melanin, mycosporine-like amino acids
(shinorine, palythine, porphyra-334, palythene and usujirene); carotenoids (dia-
dinoxanthin, zeaxanthin, myxoxanthophyll, and echinenone); algal toxins (mostly
cyanobacterial toxins produced from blue-green algae) including microccystins,
nodularins, anatoxins, cylindrospermopsin, and saxitoxins; red tide toxins includ-
ing brevetoxins (Parlanti et al.
2000
; Mostofa et al.
2009b
; Zhang et al.
2009
;
Xiao and Wu
2011
; Coble
2007
; Norrman et al.
1995
; Hanamachi et al.
2008
;
