Chapter 9 Fate modeling of benzo(a)pyrene near a refinery outfall in the coastal water of United Arab Emirates

A three-dimensional numerical modeling study is done to simulate the face of benzo(a)pyrene, a carcinogenic poly aromatic hydrocarbon, in the dynamic coastal environment after its release from a refinery outfall. In the model, pollutants are distributed in the water, organic carbons, and sediments according to specific chemical laws. In the water column, it is subject to transportation, settling and losses. Processes of burial, resuspension, bioturbation, and losses regulate its kinetics in the sediment layer. The physical transport phenomena is governed by coastal currents induced by tides, wind, and water density gradients. These dynamics are extracted from a larger regional hydrodynamics model that resolves the flow system of the entire Arabian Gulf taking into account the oceanographic and meteorological forcing. The discharging concentration of the pollutant is 10 ppb in the refinery effluent. Results show concentration of more than 0.4 ppb of benzo(a)pyrene reported at radial distance of about 3 km from outfall. In the deeper water, the concentration is found less than 0.2 ppb.