Modelowanie rozprzestrzeniania się solanki w wodach morskich na przykładzie Zatoki Puckiej

Abstract

Modeling of brine spreading in the marine environment — the case study of Puck BayA b s t r a c t. Mathematical models of hydrodynamic conditions are applied for the description of water movement in marine environments; they can also be applied for describing the spreading of substances discharged into such water bodies. In cases where brine is discharged into a marine environment, the basic problem to be solved is the intensification of the mixing process upon two fluids of substantial density difference. Due to weak mixing of such fluids, amounts of brine may accumulate at the bottom in extreme cases. Such a scenario must be avoided due to the potentially severe ecological consequences. To neutralise the negative impact of brine discharge on the marine environment, it is necessary to search for solutions which involve the mixing of discharged fluid in a receiving reservoir along with the application of natural forces (i.e. water currents in the reservoir). It is a good proposal to discharge brine into marine environments divided into small volumes, and to introduce it into the sea with a high velocity, at a certain level above the sea bed. In this manner, brine will dilute to such an extent that the mixture (sea water brine) will not be harmful to the surrounding environment upon reaching the seabed. While sinking, the sea water-brine mixture will be transported by the marine currents from the place of discharge, and will disperse through the surrounding environment. Based on the proposed example of brine discharge into the Puck Bay, the methodology of application of mathematical models to be used in determining the most environmentally friendly solution was presented. In this process mathematical models can be applied to: 1) describe spreading parameters of brine, taking into account the discharge method in the near-field (brine amount, discharge velocity, location of discharge above the sea bed, characteristics of the marine environment) using a buoyant plume model (e.g. Jet3D); 2) describe spreading of diluted brine in the marine environment in the far field using an advection-diffusion model.