التلوث المحتمل لبعض العناصر الثقيلة وبعض العوامل البيئية لمياه جدول بني حسن في محافظة كربلاء المقدسة – العراق

Possible contamination with heavy elements and some ecological parameters of water Bani- Hassan stream in the province of Karbala- Iraq

The present study was conducted on the Bani- Hassan stream, a branch of Euphrates River in the province of Karbala for the period from December 2012 to November 2013 to indicate the possible pollution of the stream waters and sediments with different pollutants, selected five sites on the distance stretched (40 kilometers) And samples were collected monthly.

The study was achieved by measurement of some physical and chemical properties of water such as temperature of Air and water, water current, water depth, Turbidity, pH .electrical conductivity, Total dissolved solids( TDS), Total suspended solids (TSS),Salinity. Dissolved oxygen (DO), Biological oxygen demand (BOD5) Total hardness (TH), and Chlorides (Cl) , as well as measurement of the concentrations of some heavy elements (Cu, Cd, Fe, Pb and Cr) in both dissolved and particulate phases in water and exchangeable and residual phase of sediments,  Also study the bacterial indicators for water organic pollution (Total Coliform bacteria, fecal coliform bacteria and fecal streptococci, bacteria). Samples were collected monthly.

The results showed that the air and water temperature ranged between (4-40) °C and (9.5-29.8) °C respectively.water current velocity recorded values ​​ranged between ( 0.1- 1 ) m / sec. The values of the water depth between (90-240) cm and turbidity values ​​recorded between (1.3-56.5) NTU which consider off limits ranged. pH recorded values ​​between (7.2-8.8) tend to light alkaline, The study showed electrical conductivity values ​​ranged between (980-1460) μs/cm, total soluble solids recorded values ​​ranged between ( 480-710 ) mg /L, the values ​​of salinity between (0.61-0.90) ᴏ% , and it promised water table under water as Oligosaline.    The results showed that the dissolved oxygen values ​​were within the limits of the standard ranged between (5.2-13) mg/L, while the Biological Oxygen Demand recorded values between (0.5-4.7 mg/L). The total hardness recorded high ranged between (189-411) mg/L, the chlorides recorded a values ​​ranged between (91-146.8) mg / L.

The present study showed that the mean concentrations of the heavy elements (Cu, Cd, Fe, Pb and Cr) of the dissolved phase in water were (0.51, 0.06, 2.78, 2.45 and 0.15) μg/L respectively, while their concentrations in the particulate phase were (29.93, 0.65, 1233.80, 20.19 and 30.64) μg/g dry weight respectively. Also the mean concentrations of the heavy elements in sediments exchangeable phase were (13.91, 0.40, 610.57, 26.98, and 34.31) μg/g dry weight respectively, while their concentrations in residual phase were (16.36, 0.07, 710.31, 13.13 and 187.48) μg/g dry weight respectively. The results show that the rates of studied heavy elements of the dissolved phase were within the parameters of the Iraqi maintenance of the pollution of rivers and drinking water, and with (WHO), while in particulates phase was an iron outside those maintenance. The rates of heavy elements in sediments recorded high values in all of stations of the study.

The results of the study recorded a substantial rise in numbers of pollution indicator bacteria (Total Coliform, Fecal Coliform, Fecal streptococcus). Total Coliform ranged between (17×10²-160×10²) cell/100 ml, fecal coliform ranged between (13×10²-160×10²) cell/100ml, while the fecal streptococcus ranged between (1.4×10²-92×10²) cell/100 ml. These rates considered as environmental and biological indicators to the existence of an impressive levels of organic pollution, and an indexes of presence of hazardous microorganisms for population health and organisms.