Pollution of the World ocean coastal area by underwater sewage disposal systems

The processes of pollution of the world ocean coastal area by underwater sewage disposal systems have been studied by the method of scale modeling at TsWiWaT. The experiments were performed using modern visualization-based laser-optical methods (PIV/PTV) to measure velocity fields of underwater and surface currents. The theory is developed to describe dynamics of turbulent buoyant jets in stratified fluids. The effect of internal-wave generation by the boyant jets has been obtained for the first time. A model is proposed to describe this process qualitatively and quantitatively in terms of the effect of self-oscillations arising in buoyant jets captured by a thermocline. Estimates of the hydrodynamic contrasts determined by inhomogeneous flows in internal waves at the free surface show that they can be detected reliably by modern methods of remote sensing. This will make it possible to use them in the future for environmental monitoring in the locations where sewage disposal systems are located in coastal ares. This work was performed as a research under a contract with ISR “AEROCOSMOS” (Moscow).

Underwater filming near sewage outflow
Top view of the outflow from a model of the sewage system diffusor in TsWiWaT experiments
Side view of an individual inflow visualized in the laser plane by the PIV method
Calculated flow velocity field

Bondur V.G., Grebenyuk Y.V., Ezhova E.V., Kazakov V.I., Sergeev D.A., Soustova I.A., and Troitskaya Yu. I. Surface manifestations of internal waves investigated by a subsurface buoyant jet: 1. The mechanism of internal-wave generation // Izvestiya, Atmospheric and Oceanic Physics 45 (6), 779–790.

Bondur V.G., Grebenyuk Y.V., Ezhova E.V., Kazakov V.I., Sergeev D.A., Soustova I.A., and Troitskaya Yu. I. Surface manifestations of internal waves investigated by a subsurface buoyant jet: Part 2. Internal wave field // Izvestiya, Atmospheric and Oceanic Physics 46 (3), 347–359.

Bondur V.G., Grebenyuk Y.V., Ezhova E.V., Kazakov V.I., Sergeev D.A., Soustova I.A., and Troitskaya Yu. I. Surface manifestations of internal waves investigated by a subsurface buoyant jet: 3. Surface manifestations of internal waves // Izvestiya, Atmospheric and Oceanic Physics 46 (4), 482-491.

Ezhova E.V., Sergeev D.A., Kandaurov A.A., and Troitskaya Yu. I. Nonsteady dynamics of turbulent axisymmetric jets in stratified fluid: Part 1. Experimental study // Izvestiya, Atmospheric and Oceanic Physics 48 (4), 409–417.