Assessment Model for Water Quality Progression of Gia, Re, and Da Do River for Drinking Water Purpose in Hai Phong City
Gia, Re, and Da Do Rivers are the main surface water resources providing fresh water to the habitants of Hai Phong City. They are at risk of water pollution due to the release of multiple waste streams along the rivers. The main objective of this study is to establish water quality models for Gia, Re, and Da Do Rivers using the MIKE 11 Ecolab model. The studied pollutants include BOD5, NH4+, NO3–, DO, etc. Pollution trends can be predicted using pollutant load generation in the water quality model. The simulation results give relatively high correlation coefficients (0.8–0.88) and the relative error of 4–18% ensures the quality of the model. Concurrently, the research team calculated the water quality index (WQI) in the 2020 dry season for eleven locations on three rivers Gia, Re and Da Do based on the following parameters: T, pH, COD, BOD5, NH4+, NO3–, DO, As, Pb, Coliform, E. coli, etc. WQI results, with the combination of field observation and simulations, show that the water quality of Gia River is very good of Re river is an average; while the water quality of Da Do River decreases gradually from upstream at a good level to downstream at an average level. These WQI results provide a high–level assessment of the river water quality, which will assist the management of surrounding wastewater treatment systems to maintain the supply of water purpose of these three rivers to Hai Phong City.