Drinking water quality assessment by using water quality index (WQI) for Hillah River, Iraq

摘要

This study evaluated the water quality for drinking by using two models, which were the Weighted Arithmetic and Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI). Results of these two models were also compared. The studyarea included four water treatment stations: Al-Tayarah (TA), New Hilla (NH), Al-Hesain (HE) and Al-Hashimyah (HA) on the Hilla River, which is a branch of the Euphrates River in the middle of Iraq. Water samples were collected monthly from January to December 2018, and nine parameters of raw and treated water were examined, such as turbidity (Tur), pH, electric conductivity (EC), alkalinity (Alk), total hardness (TH), calcium (Ca), magnesium (Mg), chloride (Cl-), and total dissolved solids (TDS). For all stations, the Weighted Arithmetic model showed that the raw water quality was categorised from "severely polluted” to "unfit for human consumption” and the treated water quality ranged from "excellent” to "severely polluted”. However, the CCME WQImethod categorised the river water as "fair” and treated water as "good” for drinking. The comparison results of two models showed that CCME WQI gave greater water quality value than the value from the other method, or the CCME WQI was possibly considered as more flexible.