Modeling of Dissolved Oxygen with Time in Urban Waterfront Using Reoxygenation and Deoxygenation Processes

Abstract

level of contamination in surface water has been a major concern to society in the reduction of oxygen in the water bodies. This study was carried out to test and validate a developed model of dissolved oxygen with time (days) in urban waterfronts. Water samples were collected at Bonny and Okirika waterfronts in Port Harcourt, Rivers State, Nigeria. This was taken at different times, depths, and distances along the river, in both dry and rainy seasons. The biological oxygen demand (BOD) and dissolved oxygen (DO) of the water samples were analyzed according to APHA-51210B. The model was validated by simulating the experimental results into the equation, and with coefficient determination (r2). The results of the analysis showed that dissolved oxygen (DO) in the creeks in the presence of oxygen-consuming pollutants in the creeks depleted the DO concentration, which attained saturation after 30 days. The saturation with DO value approximately 7.2mg/l. however, from 80 to 100 days, deficit was almost insignificant with values recorded between 4.9x10-6mg/l and 3.5x10-6mg/l for the two creeks across the seasons. The experimental results were simulated into the prediction model. The developed model showed good agreement between measured and predicted results with high coefficient of determination. Thus, suggesting that the model be used for predicting dissolved oxygen with time in the waterfronts.