Influences of Spatial and Seasonal Variation on Khabur River Pollution by Municipal Wastewater in Zakho District, Iraq Kurdistan Region

Abstract

Samples of water were collected from the Khabur River in Zakho city in Iraqi Kurdistan Region in three seasons, the summer, autumn, and winter of 2021, at three different locations, before arriving at the city, inside the city, and after passing the city, and some Physio-chemical properties of water were determined to evaluate the spatial and seasonal variation effects on the renowned Khabur River properties. The result revealed the dissolved oxygen DO, biological oxygen demand is significantly (p<0.01) influenced by the summer season than autumn and winter, as the high temperature minimizes the dissolvability of oxygen necessary for life in the water, however, the level of BOD in Khabur river in three seasons not exceeded the recommended level of WHO and Iraqi slandered 3 mg/l. The pH of the Khabur River is not significantly affected by seasonal changes, while EC is significantly affected by seasonal variation. The alkalinity of the Khabur River is significantly higher in summer than in autumn and winter, and the opposite of almost all the studied parameters that increased in winter. The river has a total hardness greater than 200 mg/l as well as total calcium and magnesium. Hardness is significantly high in winter, as the dissolution of both Ca and Mg from bedrock and soil is increased by the action of heavy rainfall on the eroded soil. Regarding the spatial variation, the most studied parameters of the Khabur deteriorated when the river enters Zakho city, as approximately all the sewage water of this city is discharged into the river without any proper treatment.