Limnological study on Zarrineh River

Abstract

Limnological studies of the Zarrineh River have been performed in order to identify physicochemical and biological characteristics of this river. Water samples from 14 sites along the river length were examined monthly during a year. The results indicated the river was polluted by Saghez and Miandoab Cities sewage to the extent of poly saprob , the extent of pollution at other sites was within the limits of oligo saprob or meso saprob. The results also showed that all dissolved and mineral compositions in this river was safe for drinking but iron concentration and water hardness in the terminal sites near the Urmia Lake are higher than EPA standards for drinking . This can not, however, pose serious problem for warm water fish culture activities. Domestic sewage seem to be the most important pollution source to this river. Although the self-purification capacity of this river seem to be high but large number of polluting sites along the river exceed this capacity.