도시 하수의 해양방류 및 근역혼합특성 분석

Abstract

Analysis of Ocean Discharges of Municipal Water and its Near-Field Mixing Characteristics

Due to the growth of population and industrial development at the coastal cities, there have been much increase in necessity to effective disposal of the wastewater. The amount of municipal water has been increased rapidly and it is necessary to treat and dispose the wastewater effectively. The recent trend, in terms of disposal of it, is discharge through diffusers into the ocean, either at the coastline or at the deep water, or between these two.

For this end, we need to predict near-field characteristics of discharged water. We adopted CORMIX model for the analysis of the near-field behavior of discharged water and made certain comparison with the existing experimental results.

We found the early dilution is important, especially for the numerical simulation by a depth averaged hydrodynamic model of diffusion mechanism at the existing flow field.

We also applied it to the Pusan Jungang Effluent Outfall System, which is planned to be in the Gamchun harbour and will be completed in 2011. The model output showed the trajectoral variation of dilution and mixing behavior for three cases of outfall system. Dilution differences have been simulated and found the highest dilution condition under the different displacement of outfall system. On the basis of these outputs it will be proposed the optimum outfall system type and location.

Through the case study, dilution is dependent on the discharge depth, the ambient velocity and total flow rate. This approach might contribute to deal with serious water quality problems caused by the ocean discharge.