Improvement of Water Quality in a Highly Polluted River in Jordan

Zarqa River is considered one of the most important sources of surface water in Jordan. The construction of Al-Samra wastewater treatment plant has caused a considerable deterioration in water quality of that river and pollution of the groundwater of that basin. This paper aims to study the change in water quality in the river by applying hydraulic and quality models. Samples of wastewater from the inlet and outlet of the plant were collected and analyzed according to the standard methods. The obtained results concerning BOD, NH4 and DO were used as input to predict water quality in the river. For this purpose, a one dimensional quality model has been developed to simulate pollutants transport in the river. The model was constructed to represent the change in concentrations of such parameters in the river from the treatment plant to the King Talal dam. 296 quality samples and 90 hydraulic samples were taken in order to calibrate the model. Results indicate that the concentrations of BOD, COD and NH4 effluent from the plant exceeded the allowable limits according to Jordanian standards. From the results of simulation, it is found that the model is applied successfully to predict water quality in Zarqa River. Due to self purification, high reduction of pollutant concentrations occur along the river .The concentration of BOD is still higher than the allowable limit until 33 km downstream of the plant, while NH4 concentration is higher than the standards in all reaches.