مختصر البحث:
The present study was conducted to evaluate some physical and chemical parameters such as (water temperature, pH,
turbidity, total dissolved solids, electrical conductivity, salinity, dissolved oxygen, biological oxygen demand, total hardness,
cal…
The present study was conducted to evaluate some physical and chemical parameters such as (water temperature, pH,
turbidity, total dissolved solids, electrical conductivity, salinity, dissolved oxygen, biological oxygen demand, total hardness,
calcium and magnesium hardness, and sulfate ions) and the concentrations of some heavy metals such as (Zinc, Lead,
Cadmium, Manganese and Iron) in water of Bahr Al- Najaf. Five sites were chosen in Bahr Al- Najaf; the samples were
monthly collected from April 2017 to March 2018. The results showed that water temperature ranged between (12.3-37.8) C0
,
pH values (7.16 -8.88), electrical conductivity (EC)(3.8-77.8) ms/cm, salinity (2.43- 49.79) ppt turbidity (Tur) (7.16 -45.5) NTU,
total dissolved solids(TDS)( 2476-32366) mg/l, total hardness (TH) ( 553.18 - 2073 )mg/l, calcium(Ca+2) and magnesium
(Mg+2)ions (122.91-689.37) and (80.29-609.21) mg/L respectively, sulfate ions (SO4
)
-2(360.9 -1263.1)mg/l, dissolved oxygen
(DO) (6.6 - 17.8) mg/l, biochemical oxygen demand (BOD5
) ( 0.73- 12.77) mg/l. The study results of heavy metals concentrations
in water showed that Zinc (Zn) ranged between (0.001-13.86) ppm, lead (Pb) (0.02- 1.87 ) ppm, cadmium (Cd) ( 0.001-3.33) ppm,
manganese (Mn) ( 0.006-0.23) ppm, iron (Fe) ( 0.03-0.91) ppm. The water quality of Bahr Al- Najaf depression under this study
was considered of salinity, slightly alkaline, very hard and concentrations of BOD5
were recorded in some months exceeding
the permissible limit. It seems clearly that Bahr Al-Najaf depression was contaminated by domestic sewage. Increasing levels
of heavy metals in Bahr Al-Najaf depression exceeded the permissible limit, giving a hint of water pollution by heavy metals.
Key words : Physicochemical, parameters, heavy metals, Bahr, Al-Najaf.
