« Mise au point d’une systématique de caractérisation
des interactions Matière Organique Naturelle Dissoute
(MOND) – Contaminants métalliques »
Thèse de Doctorat soutenue par:
M. Yoann LOUIS
En vue d’obtenir le titre de Docteur de l’Université du Sud Toulon-Var
Directeurs de Thèse :
Dr. S. MOUNIER Université du Sud Toulon Var – PROTEE
(PROcessus de Transferts et d'Echanges dans l'Environnement)
Dr. D. OMANOVIĆ Institut Ruđer Bošković – LPCT
(Laboratory for Physical Chemistry of Traces)
Université du Sud Toulon Var
21 novembre 2008
Subvention N° 03/1214910/T
Matière Organique NAturelle en miLIeu SAlé
1
SUMMARY
1.Introduction
2.Analytical protocol improvements
3.Concentrated Marine DNOM study
4.Natural Estuarine ecosystem study
5.Conclusions & perspectives
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
2
I.
Introduction
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
3
1.
Trace metals in the environment
ATMOSPHERE
Metals
Metals
SOILS
AQUATIC ENVIRONMENT
(Coastal and estuarine system)
Metals
Metals
WATER
SEDIMENTS
Anthropogenic origin
Natural origin
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
4
1.
Trace metals in the environment
Toxicity ≠ Total concentration
Toxic metals:
not needed
Pb, Hg, Cd, …
When metal became toxic ?
 depend on its speciation
“Oligoelements”:
necessary for metabolism
Metals
Cu, Fe, F, Mg, Mn, Zn, …
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
5
2.
Trace metals speciation in the water column
Filtration (0.45µm)
“Not” or less
bioavailable
Particulate > 0.45 µm
Micro-organisms
(bacteria, virus,…)
M
M
Dissolved < 0.45 µm
Inorganic Ligands
Could be
bioavailable
Cl-, NO3-, SO42- …
bioavailable
M
M n+
Organic and Inorganic
Particules
M
M
Organic Ligands
EDTA, DNOM …
M
Water
column
M
“Not” or less
bioavailable
Métal
Metal trap:
toxic
Generally
toxicLess
for biota
Dissolved metal
speciation
[MTOTAL] ≠ [MTOXIC]
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
6
3.
DNOM Origin?
Heterogeneous origins  heterogeneous and complex structure
Anthropogenic activities
Plants, animals, µorganisms
decomposition
River input
Photosynthesis
Bacterial activity
degradation
Humification&
Polymerization
 DNOM modifications
Phytoplankton activity
Representation of
a simplified NOM
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
7
4.
DNOM speciation
“Analytical speciation”
“structural” determination
separation
Dialysis, UF
CFFFF, HPSEC
HPLC, GC
C18, Chelex
…
and
“Mechanistical speciation”
Interactions characterization
analysis
GFAAS
ICP-MS
CV-AFS
Voltammetry
...
Specific components determination
Less usable for metal behavior prediction
ISE
Voltammetry
Fluorescence Quenching
…
Results usable in speciation codes for
prediction
(for example MOCO from IFREMER)
No Functional characterization
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
8
4.
DNOM speciation
DNOM-Metal interaction study
1e-7
Continuous distribution
Discrete distribution
+
[L]T (M)
8e-8
Used to describe the DNOM reactivity
M
1
KkMthermo
kM-1
6e-8
+
DNOM
4e-8
KHthermo
DNOM
2e-8
0
2
4
6
8
+
10
KCompthermo
logK
•Continuous model: NICA-Donnan
•Discrete model: WHAM
For 1 DNOM: All K and [LiT] determined = “Chimiotype”
 For Metal-DNOM interaction study: Need a technique to measure only
or
DNOM
L
M
Assuming a kinetic of 1st order
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
9
5.
Analytical tool used to measure trace metal: DPASV
3 electrodes system:
Counter electrode (Pt)
Metal-Ligand
Reference electrode (Ag/AgCl/KClsat)
Complex
DNOM
Working electrode (Hg)
Direct measurement of
Stirrer
Purging (N2)free & inoganic copper fraction
Escan
dep
=
Metal addition
OxydationStep
step
Reduction
Edep
electrolabile
After tdep =fraction
5 min
(= bioavailable
fraction)
Escan
1.6e-8
1.4e-8
eIntensity (A)
L
I=f([M])
1.2e-8
1.0e-8
8.0e-9
6.0e-9
L
DNOM
Voltamogram
4.0e-9
DNOM
L
L
2.0e-9
DNOM
DNOM
0.0
-0.5
-0.4
-0.3
-0.2
-0.1
0.0
0.1
Escan (V)
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
10
6.
Metal logarithmic scale titration (Garnier et al., 2004, Env. Technol. 25, 589-599)
pCuT
-9.50
-9.00
-8.50
-8.00
-7.50
-7.00
-6.50
-6.00
-5.50
-6.50
Discrete fitting of
experimental data with
PROSECE program
-7.00
(Speciation calculus + optimization)
-5.00
-5.00
-5.50
-6.00
-7.50
-8.00
-8.50
-9.00
[Metal added]: From nM to µM
Determination of Kequilibrium, [LT]
Determination of k1, k-1, [LT]
 New characterization of the DNOM: reactivity
-9.50
Data at equilibrium  Kequilibrium, [LT]
7.4
pCuT
7.0
1:1
Sal11 exp
Sal11 calc
Metal complexed
by DNOM
6.6
6.2
Kinetic  k1, k-1, [LT]
5.8
1.6E-08
5.8
6.2
6.6
7.0
7.4
1.4E-08
For each point:
1.2E-08
2h of equilibrium
1.0E-08
Measurements
every 6 min.
Cu (M)
7.8
pCulab
8.2
CuT
Culabile
8.0E-09
6.0E-09
4.0E-09
7.8
2.0E-09
8.2
0.0E+00
0
50
t (mn)
100
150
8.6
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
11
7.
Pseudopolarography measurements (Nicolau et al., 2008, ACA 618, 35-42)
Measured if:
UV, pH=2,
Edep << Edep for CC
Labile fraction = Free + inorganic fraction : bioavailable
Dissociable organic fraction: Probably not bioavailable
Not measured fraction = electroinactive in the Edep range used
Voltammograms
Pseudopolarogram
16
16
12
struja / A (nA)
Intensity
A
struja / (nA)
Intensity
Edep for CC
measurements
14
14
10
8
6
12
10
8
6
Direct ML
complex
reduction
Labile
fraction
4
4
2
0
-1.2
pote
-1.0
ncija
-0.8
l aku
-0.6
mula
-0.65
-0.4
cije
/
V
-0.60
-0.50
-0.45
/
cijal
n
e
t
po
-0.55
V
2
0
-1.4 -1.3 -1.2 -1.1 -1.0 -0.9 -0.8 -0.7 -0.6 -0.5 -0.4
potencijal akumulacije
/V
Deposition
potential (V)
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
12
8.
Goals of the study
Analytical protocol determination
adapted to low [DOC] and [Metal]
Real complex natural
ecosystem study
Improvements:
•Technical
•Analytical
•Mathematical
“Model DNOM” definition
Based on the concentrated
sample from GDR MONALISA
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
13
II. Analytical Protocol
determination
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
14
1. Technical and mathematical improvements
pCuT
8.0
7.5
7.0
6.5
6.0
6.0
6.5
5e-9
7.5
pCulabile
7.0
4e-9
8.0
3e-9
i (A)
8.5
experimentals points
fitted curve
peak 1
peak 2
baseline
2e-9
•Limit adsorption (Teflon use)
•Precise metal additions (automatic pumps 500µl)
1e-9
•Avoid pollution with additions (tubing separation)
0
•Avoid evaporation (N2 wet purging)
-0.5
-0.4
-0.3
-0.2
-0.1
•Mathematical baseline and peak definition
E (V)
•Multi-PROSECE (more optimization loop & confidence interval calculus)
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
9.0
0.0
15
2.
Analytical improvement: Surface Active Substances (SAS)
interferences (Louis et al., 2008, ACA 606, 37-44)
Edep
Escan
e-
e-
Intensity (nA)
12
Escan
I
14

[Cu]meas

[LT]
Distorded shape
10
8
6
-0.45V with SAS
4
2
0
-0.5
-0.45V without SAS
-0.4
-0.3
-0.2
-0.1
0.0
Escan (V)
SAS
SAS
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
16
Analytical process to get rid of SAS interferences during the
stripping step
Additional experiment A.C Voltametry (Phase angle: 90° measure of capacitive current)
250
Classical used tdep
12
100
50
0
0
200
Eacc= -0.45 V
10
i (nA)
150
Intensity (nA)
i (nA)
-0.6V
dep = V
Eacc= E-0.45
+ 3sec at -1.6V
80
Eacc= -1.6 V
14
200
100
Edep = -0.6V
+ 3s at -1.6V
8
Classical Edep
used for Cu
Max. Ads.
At pzc
-
60
+
40
20
6
Edep = -1.6V
4
t
acc
400
0
-1.6
600
-1.4
-1.2
-1.0
(s)
-0.6
-0.4
-0.2
0.0
Eacc (V)
2
ΔI ↑ = Itcap- It0cap = SAS quantity ↑
0
-0.5
-0.8
-0.4
-0.3
-0.2
Full circles Edep=60 s
Dotted circles Edep=60 s + 1s at -1.6V
Triangles Edep =60s (After UV)
-0.1
0.0
(V)
High influence of SAS at tdepE = 300
s and Edep ≈ - 0.5 V
scan
Only 1% of the total deposition time (297s)
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
17
Influence of these SAS on the apparent [LT]
1e-8
Without 3sec
[LT]= 335 nM
Intensity (A)
8e-9
logK=6.17
6e-9
With 3sec
[LT]= 160 nM
4e-9
logK=6.47
2e-9
0
0
200
Ruzić linearization
400
600
800
1000
[Cu] (nM)
[LT] change from 335 nM to 160 nM
 Artificially « Hidden Metal » by SAS  bad speciation determination  toxicity
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
18
3.
Analytical protocol for DNOM study
Potentiometry
Raw sample
Log addition window
determination :
Add1= 10% Mini
Final conc.:
1mgC/L  1µM
10 mgC/L  10µM
(Chelex)
(4)
(1)
(3)
DOC
Filtration
at 0.45µm
(8)
(5)
For concentrated samples
Pseudo  Edep
(2)
UV at pH2
Salinity or majors
ions by Ionic
Chromatography
(6)
(9)
Total Metal
(Optional)
H+ , Ca2+ competition
(After Chelex)
(7)
(10)
“Chimiotype”
PROSECE
(11)
Log additions at Edep,
Kinetic experiment
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
19
III. Study of a natural seawater sample
(MONALISA project)
(Article submitted to Marine Environmental Research)
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
20
1.
Sampling site: Balaguier Bay
> 100 nM
Military port
~ 15 nM
~ 5 nM
Site interest:
Coastal Semi-Closed Area under
anthropogenic influences
Goal: Give standard DNOM usable in metal
speciation/transport program
1000L seawater sampling (online filtration and nanofiltration and reverse osmosis concentration by GDR
MONALISA, ISM-LPTC: E. Parlanti, PhD of Arnaud Huguet).
Concentrated from 1000 L to ~10 L, [DOC]final= 30.4 mg/L
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
21
2.
Potentiometry on Concentrated DNOM
(Garnier et al., 2004, Water Research, 38, 3685-3692)
Carboxylic
like
LH1
LH2
LH3
LH4
LHiT
(meq/molC)
210 ± 10.8
54 ± 2.4
80.4 ± 1.2
100.8 ± 1.2
pKa
3.6 ± 0.1
4.8 ± 0.1
8.6 ± 0.1
12.0 ± 0.4
Carboxylic-like
Phenolic-like
5
pH
12
4
10
3
2
1
0
6
-1
-2
4
181.2
60% 40%
70% 30%
Total
acidic
Sites
446.4
/2.7
165.3
Lu and Allen (2002) : Suwanee River
Erreur (%)
8
265.2
Phenolic
like
(also concentrated by RO)
(Letizia and Gnudi, 1999)
-3
-4
2
0
0.02
0.04
0.06
0.08
nOH-ajouté (mmol)
-5
0.1
0.12
0.14
PROSECE Fitting for 4 types of acidic sites (DOC=1.2mmolC.L-1).
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
22
3. Exploratory experiment: Pseudopolarography coupled with
logarithmic addition
100
Edep = -0.5V
2nd site saturation
CuT (%)
80
60
1st site saturation
40
20
0
8
7
6
5,6
5
4,6
4
pCuT
Estimation of a [1st site]: 90% x 2.5µM = 2.25 µM (= 1.87 meq/molC)
Estimation of a [2nd site]: 50% x 25µM - [1st site]: = 10.25 µM (= 8.54 meq/molC)
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
23
4.
Log addition and Cu2+ competition with H+ and Ca2+
≈ 2µM of Cu bound to specific sites
Strong affinity toward proton
 phenolic-like sites
Strong affinity of copper for
the studied DNOM
% Cu lab
Model Marine DNOM complexing parameters = DNOM “Chimiotype”
% Cu lab
(Comparable to standards OM used in NICA-Donnan /WHAM models, obtained for soil/river extracted OM)
Ca additions
LH1
LH2
LHiT
210 ± 10.8 54 ± 2.4
(meq/mol
Edep = -0.5V,C)pH = 8.2, DOC = 1.2mmolC.L-1.
pH
LH3
LH4
80.4 ± 1.2
100.8
± 1.2
[Cu] = 12.5µM, pH = 8.2
[Cu]T = 4µM.
T
Hight complexing
calcium competition
Strong
pKa
3.6 ±site
0.1specific
4.8 ± 0.1
8.6 ± 0.1
12.0 ± 0.4
Comparison of 2 different Edep (-0.5V and -1.5V).
toeffect
copper
Total metal binding site Total acidic
LM1
LM2
density LMT
sites density
Closed to12
values estimated with
446 pseudo
LMiT (meq/molC)
1.72
±0.13
10.25
±2.7
logKCuL
9.9
±0.1
6.9
±0.1
logKCaL
2.5
±0.4
5.5
±0.6
pKa
8.6
±0.1
8.2
±0.3
coupled with log add.
~3% of
(= Buffle, 1988)
Phenolic-like sites
Complexing parameters determined after simultaneous fitting by PROSECE of the 3 experiments
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
24
5. MINEQL simulation of natural DNOM according to
determined model marine DNOM
Experimental points
DNOM simulated by Mineql adjusting only [DOC]
Difference between modeled DNOM and experimental points
<<5%
seawater sample treated with Chelex (DOC = 0.09 mmolC.L-1); pH = 8.2, Salinity 37.
• Correct simulation validating the characterization protocol
• DNOM reactivity is not strongly modified by concentration step
Model DNOM determined usable
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
25
6. Simulation of copper speciation for the studied marine
environment
Condition: Majors ions for salinity of 38, DOC = 0.09 mmolC.L-1, Cutot = 14.8nM
80% of total copper complexed as organic forms
 >90% found in several paper: Influence of SAS ?
 specific behavior of the studied DNOM and high copper content
7.5
8.3
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
26
IV. Estuarine DNOM Study
(Article submitted to Marine Chemistry)
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
27
1. Sampling site: Krka, Croatia (2007&2008)
• Sampling in the water column: 
gradient of salinity
Salinity
0
-1
0
Brackish
20
30
FSI layer
10
40
-2
-3
Depth (m)
•Low tide on Adriatic sea  stratified estuary
•Pristine watershed
•Potential anthropogenic inputs in estuary
•On site measurements in nearby laboratory
•Challenge is to give data on speciation
and kinetic in this natural area
-4
-5
-6
Seawater
-7
-8
-9
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
28
2.
Simplified protocol used
Potentiometry
Raw sample
Log addition window
determination :
Add1= 10% Mini
Final conc.:
1mgC/L  1µM
10 mgC/L  10µM
(Chelex)
(4)
(1)
(3)
DOC
Filtration
at 0.45µm
(8)
(5)
Pseudo  Edep
(2)
UV at pH2
Salinity or majors
ions by Ionic
Chromatography
(6)
(9)
Total Metal
(Optional)
H+
, Ca2+ competition
(After Chelex)
(7)
(10)
No concentration step
and no use of Chelex
PROSECE
(11)
Log additions at Edep,
Kinetic experiment
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
29
3. Salinity, DOC and Copper profiles
DOC (µMC)
Salinity
0
10
20
30
40
40
50
60
70
80
(Elbaz-Poulichet F. et al., 1991)
Cu1988
T (nM)
1.78 in may
2
4
6
8 10 12
0
-2
B
C
-4
-6
DOC
-8
12
80
10
70
8
CuT
Depth (m)
A
60
6
50
4
40
2
0
10
20
30
Salinity
40
0
10
20
30
40
Salinity
• Same curve shape for 2007  & 2008 
• Oligotrophic freshwater  Very few carbon content, DOC est. < DOC sea  low anthrop. inputs
• Non conservative behavior: Bigger amount of metal & DOC in the FSI  “special layer”
• Additional source of DOC in the FSI: can be due to an exacerbated biological activity (Svensen et al, 2006)
• Increase of copper in the FSI: particulate/dissolved metal exchange due to salinity increase
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
30
4. Comparison of the kinetic and at Equilibrium approach
Data obtained for only 1 sample: Example from Salinity 11, April 2007
8.0
8.0
7.0
pCuT
pCuT
6.5
6.5
6.0
6.0
5.5
5.5
Log K at Equilibrium
5.5
5.5
1.4E-07
8.0E-08
6
6.0E-08
4
4.0E-08
Average of Log k1 kinetic
Log k1 kinetic
6.0
6.0
erreur (%)
erreur
(%)
55
LT
LT (mol/L)
(mol/L)
logk1
logk1 &
& logKth
logKth
8
Log K kinetic
Average of Log K kinetic
Average of LT kinetic
1.2E-07
LT kinetic
LT at Equilibrium
1.0E-07
6.5
6.5
7.0
7.0
00
7.5
pCulab
pCulab
10
7.5
7.5
10
10
8.0
-5
8.5
-10
2.0E-08
Fitting
Data at Equilibrium
9.0
5.0E-08
4.5E-08
2
0.0E+00
7.7
7.5
pCuT
7.3
7.1
6.9
Good agreement between the
constants obtained at equilibrium
and with the kinetic approach
3.5E-08
Culabile (M)
7.9
4.0E-08
3.0E-08
2.5E-08
2.0E-08
1.5E-08
1.0E-08
Fitted Kinetic data
5.0E-09
0.0E+00
0
1000
2000
3000 4000
t (s)
5000
6000
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
7000
8000
31
4. Comparison of the kinetic and at Equilibrium approach
14
A
Good agreement between
constants determined at
equilibrium or kinetic
13
120
LiT Kinetic (nM)
2007 (,) and 2008 (,).
B
logKM Li Kinetic
150
12
90
60
11
At equ: Higher M/L ratio  better
[L] determination
8
10
7
6
9
5
5
6
7
8
60
90
120
LiT at equilibrium (nM)
150
9
10
11
12
13
14
logKM Li at equilibrium
Kinet.: more points after each
addition less equilibrium
dependent, kinetic parameters
determined
pCuT
7.0
6.5
6.0
6.0
4e-8
A
B
6.5
Culabile (M)
• kinetic first point estimation of Culab at t0
• Is the solution at equilibrium with the at
equ. Approach
•Both approaches are complementary
7.5
3e-8
7.0
7.5
8.0
pCulabile
Apparent overestimation of Kinetically
determined logK (or underestimation
of the at equ. approach) due to:
8.0
k1
2e-8
1e-8
k-1
8.5
0
9.0
0
2000
4000
6000
Time (s)
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
8000
32
5. Complexing parameters results
5
10
20
log K equ
i
&
LiT (nM)
In MINEQL:Cu (%)
50 100 200 8.5 9.5 10.5 11.5 12.5 13.5 0
10
20
80
90 100
0
83%
Depth (m)
-2
-4
Cu2+(M)
-6
1e-12 1e-11 1e-10
Depth (m)
0
-8
-10
A
0
B
10
20
Salinity
30
40
C
-2
-4
-6
-8
-10
Expected variation with salinity
Organic Cu
Observed variation
90 to 99%
strong (,) and weak (,) ligands, 2007 (,) and 2008 (,),
In dotted line in inset: toxicity limit of 10 pM (Sunda et al., 1987).
Difference  Autochthonous DNOM production in the estuary
Higher affinity for ligands from seawater origin
In the FSI: Higher inorganic and free copper content (up to 20pM) in spite of [ligands] increase
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
33
6. Simulation of DNOM reactivity under a Cu contamination
Omanović et al., 2006
Cu2+ (M)
CuT (nM)
0 2 4 6 8 10 12 14
0
B
A
-2
Depth (m)
1e-12
1e-11
Reaction time (min)
1e-10 0 20 40 100
200
300
C
2006
≈ 2h30
≈ 4h30
-4
-6
Used for
prediction
-8
2008
time
2008 2006
t50%
t99%
•Higher [Metal] in summer due to traffic of touristic boats
•Calculated free copper concentration potentially toxic for µorganisms at the surface in summer
•Lower reactivity of the FSI DNOM
•Compared to hydrodynamics variations tequ. are quite long  system probably not at
equilibrium in the estuary
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
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depth (m)
7. Comparison of the measured DNOM vs. the model DNOM
Determined with
the simplified
protocol
simulated from
model marine
DNOM
Higher free [Cu] with the use of model DNOM > toxicity limit
Bigger difference for marine sample  ≠ DNOM behavior between Toulon & Šibenik
Model DNOM not sufficient, even if DNOM is from same origin  This ≠ show the necessity
to study samples representatives of the studied system
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
35
V.
Conclusion
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
36
Conclusions and perspectives
• NEW use of “3sec” for DNOM analysis remove SAS interferences
•Determined protocol  NEW direct analysis of coastal natural samples at low [DOC]
and [M]
 complexing parameters determination + NEW Kinetic parameters (reactivity prediction)
 model DNOM usable in environmental contaminant speciation/transport programs
•Standard DNOM hardly usable to model DNOM behavior of a complex environment
Use of the determined protocol for specific ecosystem understanding
•Main improvement needed: Voltammograms automatic fitting
•Deeper analysis of pseudopolarograms,
•On site measurements (DGT) and comparison of data
•Actually protocol applied on a depth profile from Dycomed (Dyfamed site) …
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
37
Application of the method to an “oceanic” depth profile
[Cu]Free
1e-12
0
[Cu]Tot
1e-11
1e-9
5 nM
1e-8
Depth
-500
-1000
-1500
-2000
First results shows:
•At natural [Cu]: Cufree under toxicity limit
until simulated total [Cu] up to 5nM
•Surface DNOM is less complexant
•Still analyzing samples (Dycomed 15) and need to treat all kinetics data…
• Need to make a connection with on site measurments (Chlorophyll, COT, fluorescence … )
Introduction – Analytical protocol – Marine DNOM study – Estuarine DNOM Study - Conclusion
38
Balaguier Bay (Toulon, France)
Martinska (Šibenik, Croatia)
Merci à tous de votre attention !
Special thanks to my Directors:
Dr. Mounier S.
Dr. Omanović D.
To the Jury’s members:
Prof. Marmier N.
Prof. Riso R.
D.R. Elbaz-Poulichet F.
D.R. Cossa D.
Dr. Garnier C.
And members from PROTEE (USTV) and LPCT (RBI) labs
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