Water quality assessment and phosphorus effect using water quality indices: Euphrates River- Iraq as a case study

Most rivers in developing countries are facing water contamination problem. Therefore, saving quality by complying with the industrial, drinking, and agricultural allowable standard limits has been difficult. This study aims to assess Shatt Al-Kufa as one branch of Euphrates River calculating three types indices two cases, excluding including phosphate (PO 4 ) consentration, it was parameter that most met standard. The used Weight Arithmetic Water Quality Index (WAWQI), Canadian Council Ministers Environment (CCMEWQI) Oregon (OWQI). Fifteen parameters were analyzed, pH value, Biological Oxygen Demand, Turbidity, Total Hardness, Orthophosphate, Sulphate, Nitrate, Alkalinity, Potassium, Sodium, Magnesium, Chloride, Dissolved Oxygen, Calcium Solids. results show average WAWQI for stations, PO , 33.79, 43.75 37.62, which is good water. However, PO4, characterized very poor depending on resulting values (86.62, 88.86 91.91, respectively). CCMEWQI stations 63.83, 60.40 55.69, so fair marginal. According OWQI, cases since OWQI value less than 59. Pearson correlation shows a link, especially total hardness dissolved solids salt. • resources significant part ecosystem affected significantly population urbanization. Three Al-Najaf city, Iraq, selected evaluate improvement using indices: WAWQI, CCMEWQI, OWQI. more compliance thus effect calculated case its inclusion exclusion. not weight importance, their changed largely presence or absence.