Abstract

The water quality of Da Nang Bay (Viet Nam) isone of the major issues on Da Nang City's coast. The dischargeof the Phu Loc (PL) channel will be inserted through the outletinto Da Nang Bay. However, the PL channel receives manysources of wastewater so the highly polluted channel water.Therefore, the outlet of PL channel has become theenvironmental hotspot of the Da Nang Sea. Mike 21 FMHydrodynamics module coupled with a water quality modelusing Mike 21 FM ECOLab module is used to simulate waterquality and to identify the spreading of NH₄⁺, which is used as apollutant tracer. Currently, the outlet of PL channel generatesthe polluted area along the coast in different directionsdepending on the current and the direction of the wind. Thisstudy proposes three scenarios of designing the outlet far fromthe coastline 400 m, 500 m, and 600 m, respectively. The findingof this research demonstrates that the best way to discharge thewastewater from PL channel would be the outlet to be moved500 m away from the coastline. NH₄⁺ concentration > 0.2 mg/lwill cover an area that distributes about 100 m around thecoastline. NH₄⁺ concentration > 0.5 mg/l covers an areaapproximately 0.03 km².