Assessment of Qualitative Parameters of Gamasiab River and Effective Factors on These Parameters

In this survey to analyze the effect of Aquaculture Farms on quality of Gamasiab Rive, we selected five sampling station along the river for sampling. Water quality parameters were determined and then compared with standard limits. Sampling was done in three months August and September 2007 and March 2008 in the morning and evening because of the effect of Feeding in water quality. The water samples were gathered in polyethylene bottles and DO, pH, EC were determined at the station then samples were transferred to the lab for determining other parameters such as BOD5, NH4+, NO3-, NO2- and PO43-. The results showed that only EC has no significant difference in stations but other parameters have that. For DO, pH and BOD5 parameters only between B1 station and control station (A) have not showed significant difference. NH4+ and NO3- have showed significant difference between control station (A) and the others because of inputting the nutrition particles of aquaculture facility and village's wastewaters in the river. Also, between Aquaculture Farms there are significant difference in some parameters like NH4+ and NO3-. For instance Ghazal Danesh farm with producing 100 tone fish entered more pollution to the river comparing with Ghazal Zaghros farm with producing 190 tone fish.Discussion and Comparing the water quality parameters in Gamasiab River with water quality classification table in physical, chemical and biological parameters showed that this river water quality is in α-meso saprobe until β-meso saprobe. So, at present this river can do self-purification of pollution but because of the policy of developing Aquaculture Industry in Iran, especially Hamedan province and no controlling and monitoring on pollutant sources, this river would have serious problems such as purification in the future.