Assessment of WQI and microbial pollution for two water treatment plants in Baghdad City

Abstract EN

Tigris River is the main water source for all water treatment plants in Baghdad city.

In current study, Water Quality Index (WQI) and microbial pollution was obtained for two water treatment plants and their networks in Baghdad city Al-Karama and Al-Wathba WTP for both raw and treated water, In order to assess water suitability as a source of domestic water supply.

Physical, chemical, and Microbialparameters werestudied fora period of four months (March-June, 2014).

The parameters which were taken into account for the present work are pH, turbidity (Nephelometric Turbidity Unit), Total Alkalinity (TA), Electrical Conductivity (EC), Calcium (Ca++), Magnesium (Mg++), Total Hardness (TH), Total Dissolved Solids (TDS),Chloride (Cl-), and Most Probable Number (MPN) method as microbial pollution indicator.

The results indicate that WQI for untreated Tigris water was classified as "unfit for human consumption" at both WTPs intakes and along study period and after water passing through the sequence treatment units in WTPs its quality is gradually increased and finally, the treated water quality ranged from "Good" to " Moderately polluted" at both All-Karama and Al-Wathba WTPs.

In networks the quality of water ranged between "Good" to "moderately polluted" in Al-Karama WTP network and between "Moderately polluted" to "severely polluted" in Al-Wathba WTP network.

For Microbiological pollution, MPN throughout the period of study was between (0-150 cell/100ml) at Al-Karama WTP and between (0- 240 cell/100ml) at Al-Wathba WTP.

The highest value obtained was (240 cell/100ml) at raw water in Al- Wathba WTP intake in June, while the lowest value obtained was (0 cell/100ml) at all chlorinated samples