2. Material and Method
This work has been borne out in Jajroud River -that is located in 50˚ 51' N to 50˚ 55' N of longitude and 34˚ 55' E to 35˚ 05' E of latitude -over a period of a year and by month sample-taking. Jajroud River is situated 30 km North-East of Tehran (capital of Iran) and flows from its origin (Alborz Mountains) to the lower altitude. Many villages were irrigated by this river. Its basin has an area of 710 km². Referable to the mountainous area and the problem of waste disposal, all the wastewater of villages enters to the river. Water coming from the Latyan dam supplies drinking water to approximately two million six hundred thousand people in East Tehran. Thus, it is necessary to protect water quality.
At the origin, by various quality-based sample taking,