Evaluating the effects of medical city wastewater on water quality of Tigris River

Abstract EN

Physiochemical characteristics of Tigris river water were examined monthly to assess the possible impacts of wastewater discharged from Baghdad Medical City hospital for the period from October 2012 to September 2013.

Four sites were selected during this study; the first was located about 500 meters before the Medical City Complex to act as control.

The second was the discharge point of Medical City discharge.

The third was almost 500 meters away south the second site, and the forth was located about 1500 meters away from the third site.

Water samples were collected monthly from these four sites, at depth of approximately 10-20 cm of water surface and subjected for determination several physiochemical variables such as temperature, pH, Electrical Conductivity (EC), turbidity, DO, COD, BOD, total hardness, chlorides and nitrate.

The obtained results showed that air and water temperature mean values varied from 13.0 ± 2.86 to 31.0 ± 5.28 C ° and from 12.0 ±3.12 to 29.0 ±4.33 C° respectively.

Also, mean turbidity values were found to range from 10.0±5.64 to 138.0±14.58 NTU while EC mean value was situated between 621.0±44.67 ^S/cm and 1549.0±162.83^S/cm.

However, this study has found that the mean values of EC, turbidity, chemical oxygen demand, chlorides, total hardness, and nitrate in site 2 (discharge point) were significantly (P>0.001) higher than those of other sites during the study period.

In general, it was found that Tigris river water tends to be alkaline with pH mean values ranging from 7.0 ± 0.42 to 8.8± 0.68 while DO mean values varied from 2.5±0.62 to 9.6±0.94 mg/l.

The BOD mean values were found to range from1.7±0.26to5.0 ±1.86 mg/l, while COD mean values varying from56.6±8.98 to688.6±112.42 mg/l.

In addition, the current results have shown that total hardness mean values were very high and ranged between 235.0±24.56and 530.0±78.68 mg/l while chlorides mean values ranging from45.0±10.44 to 143.6±21.26 mg/l, but nitrate mean values were found with the range of 2.5±0.86and 28.8±4.98 mg/l.

These results, however, have been found to be mostly exceeding those of the permissible limits for Iraqi and WHO standards for protecting surface water.