LEVELS OF NICKEL AND VANADIUM IN SEAWATER FROM AREAS AFFECTED BY THE PRESTIGE SHIPWRECK ONE YEAR AFTER THE DISASTER Juan Santos Echeandía, Ricardo Prego and Antonio Cobelo-García Departamento de Biogeoquímica Marina Instituto de Investigaciones Marinas (CSIC) Vigo, 13th July 2005

INDEX  INTRODUCTION  EXPERIMENTAL DEVELOPMENT  MARINE CAMPAIGNS: Material & Methods  PRACTICAL APPLICATION OF THE METHOD: Results & Discussion  CONCLUTIONS

INTRODUCTION Atmospheric inputs: 1. Wet deposition 2. Dry deposition Terrestial inputs: 3. Rivers and run off 4. Industrial waste 5. Sewages Other inputs: 6. Ship spills 7. Tanker sinks 8. Oil refineries

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

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

Variable optimization: Variation of the ligand concentration

Variable optimization: Influence of thesolution´s pH

Variable optimization: Study of the deposition potential

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

Detection limit Blanks analysis: Cu Ni V Deposition time (seg) Blank concentration (x ± σ, nM) 0.46 ± ± ± 0.11 Detection limit (3σ, nM)

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 Nickel x  σ, nM 5.4 ± ± 0.5 Vanadium x  σ, nM 22.1   3.1

U (-V) Ip (nA) 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 Punto de muestreo Banco de Galicia PRACTICAL APPLICATION OF THE METHOD: Results & Discussion

2. Galician continental shelf PRACTICAL APPLICATION OF THE METHOD: Results & Discussion

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.