Seasonal Variations in the Physico-chemical and Biological Characteristics of Al-Gharraf River within Al-Haay City Southern of Iraq.
Keywords:: physic – chemical and biological parameters, water quality, Al-Gharraf river.
The study reports the seasonal changes in water quality of Al-Gharraf, one of the main tributaries of the Tigris river. Monthly sampling was carried out from December 2015 till November 2016 for a year. The study location situated in the south-eastern sector of Iraq and surrounded by wide and fertile agricultural lands. Three stations were selected to. The former is located at 5 km before entrance of AL-Hayy City as control. The second is situated at distance 5 km away from the former (mid of AL-Hayy City) represented study area and the latter station is located at 15 km apart from the second one (end of AL-Hayy City). collecting samples monthly ,two samples were taken each month.
In the present study Fourteen physical and chemical parameters were analyzed based on the importance of these parameters. These Fourteen parameters are ranged as following: air temperature (16 to 32) ºC, water temperature (11 to 26) ºC, pH (7.05to 8.35), E.C. (827 to1558) µS/cm, salinity ( 0.54 to 0.99) ppt, DO (7.04 to 10.38) mg/L , BOD ( 0.90 to 7.01) mg/L ,turbidity (31.0 to 177.0) NTU, TDS (550.78 to 1108) mg/L , TSS (38 to 636.5) mg/L , T.H (275 to 520) mg/L , Cl- (95.9 to 213.7) mg/L, NO3 (15.4 to 25.0) mg/L and PO4 (0.15 to 0.59) mg/L. The results showed that most parameters are exceeding permissible limits for Iraqi standard specifications and WHO standard for drinking.
The study results also showed that the heavy metals concentrations (cadmium and lead) were 0.002-0.089 ppm and 0.031- 0.21 ppm respectively. Concentrations of these metals of Al-Gharraf River showed seasonal variations during the study period and they are exceeding permissible limits for Iraqi standard specifications and WHO standard for drinking.
The highest bacterial count was recorded at sit.2 the during winter 2016, 2800 cell /1 ml , whereas the lowest value was found during summer 2016, 320 cell /100ml. whereas numbers of E.coli were (230-1700) cell/10ml.