Shahrzad Khoramnejadian, Forouzan Fatemi
"The present study was aimed to test the water of the Damavand River in Iran for fecal coliforms, total coliforms, nitrate and pH in order to investigate the microbiological quality of this river. Water samples were collected from 10 stations along the river over a three month autumn period in 2015. Coliform bacteria and nitrate levels were examined by multiple tube fermentation method and ultraviolet spectrophotometric screening method, respectively. The values of fecal coliforms and total coliforms were expressed in most probable number/100 mL. PH was measured in the field. It was noticed that significantly (P<0.05) lowest means of fecal coliforms (191.00±29.04), total coliforms (523.33±35.19) and nitrate (2.97±0.05 mg/lit) were in station 1 that was located at the most upstream point. The downstream stations showed the highest levels of fecal coliforms (800.00±00.00), total coliforms (1600.00±00.00) and nitrate (16.00±0.01 mg/lit) as a result of domestic sewage discharges and agricultural land runoff. No significant differences found between pH levels in the stations. Nonsignificant variations were observed with regard to pH, nitrate and coliforms concentrations in the studied months at 95% confidence level. Fecal and total coliform counts were positively correlated with each other and with nitrate levels (P<0.01). There was also a positive correlation between pH and total coliform levels at 95% confidence level. Coliform levels in the stations were highly above the World Health Organization limits for domestic and recreational purposes while nitrate and pH concentrations were below this standard."