Assessment of pollution of the river Buriganga, Bangladesh, using a water quality model

The River Buriganga, which runs past Dhaka City, is at present one of the most polluted rivers in Bangladesh. Dhaka City is very densely populated and will be one of the ten ‘Mega Cities’ by the year 2000. However, only a small fraction of the total wastewater being generated in the City is treated. Consequently, the amount of untreated wastes, both domestic and industrial, being released into the Buriganga is tremendous and is increasing day by day. Therefore, the objectives of this study were to investigate the status of the river water quality in terms of some cardinal water quality parameters, and to simulate the dissolved oxygen (DO) level using a water quality model. In order to fulfil the objectives, a comprehensive data acquisition programme – from both in situ and laboratory testing – was carried out. Then, a one-dimensional water quality model was developed for the Buriganga River system for a dry period of 1994-95. Different scenarios were tested to predict the most likely condition of the river. The results of the model simulations have replicated the alarming low DO level in the Buriganga. Option runs show that an integrated approach would be required to restore the river water quality with regard to biodegradable pollutants.