Develop and Apply Water Quality Index to Evaluate Water Quality of Shatt-Al-Hilla River

Abstract

This study is an attempt to develop Shatt-Al-Hilla river water quality index (WQI) which can be applied to evaluate the general water quality of the main Iraqi rivers or streams in its entire stretch for public uses. The index proposed in this work is composed of seven measurable parameters: Total hardness (TH), Electrical conductivity(EC),Acidity (PH), Total dissolved solids (TDS), Sulphate(SO4), Calcium(Ca). Chloride(CL). WQI is a mean to summarize large amount of water quality data into simple terms (e.g., good or poor) for reporting to authorities management and the public in a consistent manner. Visual Basic can be effectively used to evaluate the variations of surface water quality in any rivers or stream in Iraq.In the present study, surface water samples were gathered (monthly two samples) from differentfive regions located at Shatt Al-Hillariver during culturing period from October 2014 to September ,2015.Sodium absorption ratio(SAR), permeability(PI)and magnesium hazard(MH) were calculated to evaluate the water quality depending on arithmetic method of (WQI) and Iraqi standard No.417 for 2004.Values of WQI ranged from (45.789 -37.234)at Hilla city and rated good according to the classification of Iraq Standard ,2004 and WHO ,2004. These values belong to high water electrical conductivity and chloride of the studied wells comparable with other parameters. Also, correlation coefficient support this interpretation where there are strong positively correlation between WQI values and both electrical conductivity and chloride values (0.987, 0.909 respectively).As a compared with SAR for all five stations ,there values are ( S2) with( 12-18), and sodium (%) ( 35-54),it means permissible type according to specification of Na%. These values associated with both EC and Cl- in a strong negatively correlation (0.990, 0.912 respectively).Application program can be considered as a good and fast tool to evaluate (WQI) for every river or stream in Iraq.