Long-term analysis on determination of deoxygenation rate of urban river water

Abstract

Water quality modeling is one approach in developing river management strategies. The deoxygenation rate is an important coefficient in the water quality of rivers modeling. This study aims to obtain a coefficient of deoxygenation rate using long-term method that can represent the condition of urban rivers with high levels of pollution. The study location was the Cikapundung River, which runs through Bandung, Indonesia. The method used to determine the rate of deoxygenation is long term, with an analysis period of 30 days in the laboratory. The Slope Method and empirical equations from Hydroscience were used to process the data. The results showed that the deoxygenation rate ranged from 0.230 to 0.291 per day. The value of the deoxygenation rate ranges from 0.40 to 0.81 per day using the Hydroscience empirical equation. The overall biochemical oxygen demand Ultimate (La) ranged from 62.03 to 77.18 mg/L. The deoxygenation rate value obtained using the long-term method shows a relatively higher result than the value obtained using the short-term time range. The long-term method is better than the short-term method because the results obtained from the long-term method are closer to the results of the empirical equation.