Methodology for Wastewater Discharge Modeling – Application to Danang Bay, Vietnam

The water quality of Danang Bay is one of the major issues on the coast of Danang City. The discharge will be inserted into this study domain through the outlet of the Phu Loc Channel. Mike 21 FM Hydrodynamics module coupled to a water quality model using Mike 21 FM ECOLab module is applied to simulate the water quality and to identify the spreading of NH₄⁺, which is used as a pollutant tracer. Currently, the outlet of Phu Loc channel has a flow-directed wall which leads the water toward the centre of Danang city. As a result, the study suggests three scenarios of wastewater management from the outlet of Phu Loc channel. The first scenario is that the wastewater will discharge along with the current flow-directed wall. Second, the flow-directed wall will be reconstructed toward the reverse direction compared to the current direction. Third, the current flow-directed wall will be destroyed. Out of three proposed scenarios, the first one generates the longest polluted area toward the centre of the city, along the Danang Bay. Consequently, the current flow-directed wall is not the best way to discharge the wastewater of Phu Loc Channel. The finding of this research demonstrates that the best way to discharge the wastewater from Phu Loc channel would be a flow-directed wall reconstructed toward the reverse direction.