LEVELS OF NICKEL AND VANADIUM IN SEAWATER LEVELS OF NICKEL AND VANADIUM IN SEAWATER

FROM AREAS AFFECTED BY THE PRESTIGE FROM AREAS AFFECTED BY THE PRESTIGE

SHIPWRECK ONE YEAR AFTER THE DISASTERSHIPWRECK ONE YEAR AFTER THE DISASTER

JJuanuan Santos Santos Echeandía, Ricardo Prego and Antonio Cobelo-GarcíaEcheandía, Ricardo Prego and Antonio Cobelo-García

Departamento de Biogeoquímica MarinaDepartamento de Biogeoquímica Marina

Instituto de Investigaciones Marinas (CSIC)Instituto de Investigaciones Marinas (CSIC)

Vigo, 13th July 2005Vigo, 13th July 2005

INDEX

INTRODUCTION

EXPERIMENTAL DEVELOPMENT

MARINE CAMPAIGNS: Material & Methods

PRACTICAL APPLICATION OF THE METHOD: Results & Discussion

CONCLUTIONS

INTRODUCTION

1

2

3

4

4

4

678

5

Atmospheric inputs:1. Wet deposition2. Dry deposition

Terrestial inputs:3. Rivers and run off4. Industrial waste5. Sewages

Other inputs:6. Ship spills7. Tanker sinks8. Oil refineries

INTRODUCTION

INTRODUCTION

• High concentrations of V (382 μg/g) and Ni (96.5 μg/g) in the fuel (nº 6, UK classification)

• Fuel emulsion releasing metals to the water

- High levels of copper in the waters from the sinking area(Prego & Cobelo-García, 2004 )

- Lost of Cu (32%), Ni (34%) y V (18%) in the fuel arriving the coast in comparison with the fuel coming from the tanker sunk.

OBJECTIVES

• Development of a method for the simultaneous determination of Cu, Ni and V in water

• Study and evaluation of the possible contamination by Ni and V derived from the Prestige fuel in galician coastal areas

EXPERIMENTAL DEVELOPMENT

- Development of a method by means of an electroanalytical technique (voltammetry) based in the cathodic redisolution (ACSV) for the simultaneous determination of Cu, Ni and V.

- The voltammetric techniques give us a ratio between the metal concentration in the sample and the peak height obtained from a potentials scan and it consists in three main steps:

- Preconcentration

- Rest

- Redisolution

EXPERIMENTAL DEVELOPMENT

EXPERIMENTAL DEVELOPMENT• Variable optimization:

- Variation of the ligand concentrations

- Influence of the solution´s pH

- Study of he deposition potential

- Effect of the deposition time

• Aplication range

• Detection Limit

• Reference Material

Catecol (mM) 0.0 0.5 1.0 1.5 2.0 2.5 3.0

Ip (

nA)

0

1

2

3

4

5

Cu V Ni

Variable optimization: Variation of the ligand concentration

DMG (mM)

0.0 0.2 0.4 0.6 0.8 1.0

Ip (

nA

)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Cu V Ni

pH

6 7 8 9

Ip (

nA)

0

1

2

3

4

5

6

CuVNi

Variable optimization: Influence of thesolution´s pH

Udep (-V)

0.0 0.2 0.4 0.6 0.8 1.0 1.2

Ip (

nA)

0

1

2

3

4

5

6

Cu V Ni

Variable optimization: Study of the deposition potential

Tiempo de deposición (min)

0 2 4 6 8 10

Ip C

u(n

A)

0

2

4

6

8

10

12

14

Ip N

i,V (

nA)

0

1

2

3

4

Cu V Ni

Variable optimization: Effect of the deposition time

Aplication Range

After making standard additions it was observed that the linear range arrived until:

Cu: 80 nM

Ni: 150 nM

V: 100 nM

[Cu] nM

0 20 40 60 80 100 120 140 160

Ip C

u (n

A)

0

10

20

30

40

50

Detection limitBlanks analysis:

Cu Ni V

Deposition time (seg)

200 200 900

Blank concentration

(x ±σ , nM)

0.46 ± 0.16 0.79 ± 0.13 0.31 ± 0.11

Detection limit

(3σ , nM)

0.5 0.4 0.3

Reference Material

Determination by means of ACSV of Cu, Ni and V in the reference material CASS-4 of coastal waters.

CASS-4

Element Obtained Concentration Certified Concentration

Copper

x σ , nM 9.7 0.9 9.4 0.9

Nickel

x σ , nM 5.4 ± 0.8 5.4 ± 0.5

Vanadium

x σ , nM 22.1 1.3 23.2 3.1

U (-V)

Ip (

nA)

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

2

4

6

8

10

12

14

16

18

20

Cu

V

Ni

Resultant voltammogram

MARINE CAMPAIGNS: Material & Methods

Galician continental shelf

Sinking area

PRACTICAL APPLICATION OF THE METHOD: Results & Discussion

Analysis of Cu, Ni and V in the fuel.

Ratio of Ni/Cu in the

fuel: 29

Ratio of Ni/Cu in the fuel: 86

Cu Ni

32% Cu

34% Ni

18% V

1. Prestige sinking area

L a C o ru ñ a

V ig o

O p o rto

N

W1 3 º 1 2 º 1 1 º 1 0 º 9 º 8 º

4 1 º

4 2 º

4 3 º

4 4 º

P ro fu n d id a d e n m

4 5 7 3

1 8 2 9

3 6 5 8

9 1 52 7 4 4

1 8 2 9 9 1 51 8 3

Punto de muestreo

Banco de Galicia

PRACTICAL APPLICATION OF THE METHOD: Results & Discussion

Dep

th (

m)

Concentration (nM)

0 5 10 15 20 25 30 35 40 0

50

100

150

1000

2000

3000

4000

190

Ni V

2. Galician continental shelf

PRACTICAL APPLICATION OF THE METHOD: Results & Discussion

42º5´

9º

Finisterre Cape

Ria Muros

Ria Arousa

Ria Pontevedra

Ria Vigo

11º 0º

38º

8º 25’

Cies

Ons

1

2

3 4

5

6

7

8

43º

42º

43º

0 5

10

20

30 Km

Cornide de Saavedra

42º00´ N 43º00´ N 42º30´ N

42º 00´ N 43º 00´ N 42º 30´ N

1

2

3

4

5

6 dissolved total

Ni [nM]

1

2

3

4

5

6 dissolved total

V [nM]

Distance (km) 0 20 40 60 80 100

5

10

15 20

25 30

35

40 dissolved total

Distance (km) 0 20 40 60 80 100

10

20

30

40 dissolved total

35

25

15

5

SURFACE BOTTOM

CONCLUSIONS

A. Method set up for a wide range analysis of Cu, Ni and V in various types of waters (estuaric, coastal, oceanic, etc.), suitable for areas exposed to fuel dumps or other pollutants.

B. Determination of Ni and V levels in waters from the western galician continental shelf and the water column above the Prestige tanker sunk area. These metals are released from the fuel but only Ni seems to increase water levels punctually (sinking area). The mixing of the waters results in an attenuation of its levels in the Galician continental shelf.