08 Nov Eduardo, Jr. Bornilla
A chemical engineer from the Philippines who works as freelance environmental research consultant for water quality management and climate change. He completed core courses in MS Marine Science at the same university where he worked on this study for his thesis. He will be an incoming student at the Griffith University – Nathan under the Master of Integrated Water Management this February 2020.
Development Of A Dissolved Oxygen – Biochemical Oxygen Demand (do-bod) System Dynamics Model Of Pasig River, Philippines Using Stella
The dissolved oxygen (DO) is one of the most measured water quality parameters as it provides the most information about aquatic ecosystem health and water condition. The dynamics of the dissolved oxygen and the biochemical oxygen demand (BOD), a major water quality parameter that affects the DO concentration, results from a complex interaction of physical and biogeochemical processes. The interrelation of DO-BOD, coupled with other water quality parameters, is explored using the visual programming software STELLA. The expanded Streeter-Phelps model, taking into account the reduction by BOD decay and denitrification and the addition by natural reaeration, is encoded to simulate the changes in the dissolved oxygen and biochemical oxygen demand concentrations as the water flows downstream. The model is applied to study the case of Pasig River, a tidally-influenced river system that drains most of the Philippine National Capital Region into the Manila Bay. In support to the on-going strategies to restore the water quality of the Pasig River, the model reconstructs BOD pollution transport to identify the hypoxia hot spots along the river channel and to estimate the BOD load contribution of the Pasig River watershed to Manila Bay. A graphical user interface allows the user to modify input parameters and to visually see the simulation results in graphs and tables. After conducting sensitivity analyses, several scenarios were explored using actual Pasig River water quality data for normal conditions, wet season and dry season. The model results were compared with the minimum 5 mg/L dissolved oxygen and the maximum 7 mg/L biochemical oxygen demand standard for Philippine Class C water.