Metal contamination in sediments from a desalination plant effluent outfall area.

To assess the impact of seawater desalination effluent discharges on the receiving water body, the outfall area of a small desalination facility on the northwestern coast of the Arabian Gulf (Saudi Arabia) was investigated for metal contamination. Sediment samples were collected from a 6 x 6 km2 area and were analyzed for metal concentrations. Cadmium, cobalt, copper, mercury, vanadium, iron, phosphorus and zinc were very high in the sediment samples from the immediate vicinity of the outfall, and decreased progressively away from it. Contour maps of elemental concentrations confirm the above conclusions. Barium and chromium showed a decreasing trend towards the outfall, but this could be related to drilling activities in a nearby oil field (barium and chromium were high in the drilling mud). Concentrations of nickel, lead, and titanium exhibited no general trend in the sediment samples.