Using a hydrodynamic model to evaluate the discharge of urban sewage on the pollution of coastal areas Case study: Bandar Abbas city

The discharge of urban and industrial wastewater is a phenomenon that occurs in cities and coastal areas. In our country, due to having a long coastal strip and numerous cities and villages adjacent to the sea in the north and south of the country, the discharge of sewage into the sea is an environmental issue that should be carefully investigated and evaluated.
In this research, the MIKE 21 FM numerical model will be used for hydrodynamic simulation and pollution transfer. This model belongs to the Danish Institute of Hydrodynamic Studies (DHI) and is used in engineering fields in the fields of environment, water, coasts and ports. The graphical and user-friendly environment of this model and the extensive capabilities and facilities and assurance of the results and outputs of this model are among its expensive features.
The spread of pollution in water environments is an increasing phenomenon. Concern about the environmental and economic consequences caused by the spread of pollution in aquatic environments has forced researchers to conduct a lot of research in this direction and provide models to investigate this phenomenon and predict its effects. One of the methods that can help in predicting and moving pollutants in water environments is numerical modeling.
This research included four main sections with different topics. The first issue was the investigation of the treated wastewater from the Bandar Abbas treatment plant, which is discharged into the Gorsuzan estuary. Although, by examining the external features of the discharge area and the resulting bad smell, high turbidity and formation of foam in the water inlet, this issue is evident.
Another issue is hydrodynamic and qualitative modeling of the marine environment. For this purpose, two-dimensional Mike model has been chosen. First, hydrodynamic modeling is limited to the entire Persian Gulf. Then, from the results obtained from the calibrated model of the Persian Gulf, the water level data at the border of Bandar Abbas area have been extracted and the local hydrodynamic model has been established. Finally, the qualitative model has been established and implemented based on the discharge location and qualitative data of wastewater discharged into the environment and other available data from sampling and measurements. In this way, the spread of pollution has been investigated.
The results show that the discharge of treated sewage into this estuary and even outside the estuary and near the coast will not solve the problems of this area, according to the trials and errors and checking the depth and average speed and direction of currents in the area, the only way The solution is to use atfal with a minimum length of 2000 meters and a depth of about 7 meters. In this case, the possibility of creating eutrophic conditions in the estuary and coastal areas of Bandar Abbas will be greatly reduced due to the discharge of treated wastewater.