Evaluation of physicochemical parameters of waste water from rainbow trout fish farms and their impacts on water quality of Koohrang stream – Iran

Abstract

Physicochemical parameters of rainbow trout farm water were evaluated to assess the potential of fish farm effluents on stream water quality. Seven fish farms were selected at Rostamabad region located on 70 km at south-west of Shahrekord-Iran. Water samples were collected from fish farms inlet and outlet at first and second sampling point. Significant differences were observed in some water factors such as total hardness, total dissolved solid, total suspended solid, COD, BOD5, dissolved oxygen, phosphate, nitrite, nitrate and total ammonia between inlet and outlet water of fish farms where as there were no significant changes in pH, sodium chloride and water temperatures. All of the water factors because of self-purification potential of the stream were in desirable amounts in third sampling point. Feasibility study carried out to assess the distance for making consecutive fish farm along the stream. It was observed that it is possible to make consecutive fish farms at around 1500 m distance but it is depended on stream water discharge and self-purification of the stream. Key words: Water pollution, trout farm effluents, environmental impact, Koohrang stream.