ENVIRONMENTAL MONITORING OF AL-MUSAYYIB RIVER AS A LOTIC AQUATIC SYSTEM IN MIDDLE OF IRAQ BY APPLICATION OF CANADIAN MODEL OF WATER QUALITY INDEX AND INDEX OF HEAVY ELEMENTS POLLUTION (HPI) AND INDEX OF CONTAMINATION ( CD)

The water quality index (WQI) is a tool used to definition whether water is suitable for aquatic life and river used to irrigation (IWQI). The goal of this work is to assess the water quality of AL-Musayyib River as a lotic aquatic system in middle of Iraq. Four sites were selected on the study area and seventeen physicochemical parameters and calculate index of heavy elements pollution (HPI) and index of contamination ( Cd) were applied to assess the validity of water to different use from January 2021 to December 2021, the studied period were divided into four seasons (Winter, Spring , Summer , Autumn) . This parameter was (water temperature, pH, DO, BOD5, TDS, NO3, NO2,Ca, Mg, PO4, Cr, Fe, Cu , Zn, Pb, Ni, Cd ). The findings of the present study showed were recorded that the HPI values that were the higher than the critical pollution index average mean value of (100), with ranged between 74.38388 to 238 .5592 in St.3 for winter and St.2 for spring. The high value of Index may be due to the rise in elements Fe; Cu and Zn more than the permissible limit for portable water and concentration of heavy metal It is attributed to the presence of many resins such as affect the concentrations of heavy metal , such as : direct drainage from farmlands, dredged materials from the river's upper reaches, as well as the diluting and increase of the water, sewage treatment plants, sediment dissolution, rises in phytoplankton counts in water, accumulation within body organisms , adsorption on surface clay , and binding with organic materials . As for the contamination index (Cd) the values of (Cd) ranged from (23.061-84.070) in site three in winter and site two in spring Fig. Cd >3 the pollution is high. Water quality status Poor- marginal may be due to mainly man - made sources in the area such as waste disposal, industrial waste discharged untreated, solid municipal waste and treatment process.