Use of water quality index and dissolved oxygen saturation as indicators of water pollution of Erbil ًWastewater Channel and greater Zab River

Abstract EN

The present investigation was conducted on Erbil wastewater channel to evaluate water quality and pollution strength by using water quality index and oxygen saturation percentage.

Seven sites were chosen for the present survey, three of them were within Erbil wastewater channel and the other four sites located in Greater Zab River.

Water samples were collected at regular monthly interval periods beginning at May 2006 to April 2007.

Some water parameters were analyzed in both water ecosystems including, water temperature, pH, EC, turbidity, DO, BOD5, COD, NH4, NO2, NO3, and total dissolved phosphate.

Water quality index was varied from 47, 53.7 to 55.4% for Erbil wastewater channel sites respectively, which classified as bad to medium type of water or as marginal type of water, while for Greater Zab River sites was varied from 71.8% at site 4 then decreased to 68% at site 5 and increased gradually from 71.1 and 71.3% at last two sites of river respectively, which classified as medium to good type according to European Union classification and as fair type water depending on Canadian classification.

The variation of oxygen saturation appeared to be directly proportional to the water quality index.