Investigation of effluent quality of trout fish farm, case study "Amole region"

Untreated effluent in most trout culture farms in Mazandaran province is discharged into the environment. Characteristics of effluents from seven flow-through trout farms in the plain of Amol city are investigated. Water samples were taken from both inlet and outlet of fish farms. Thirteen physical and chemical parameters of effluent that were analyzed indicated that the concentrations of Dissolved Oxygen (DO), Electrical Conductivity (EC), Nitrate (NO3-), Chloride (CL-), Iron (Fe), sulfate (SO4-2), phosphate (PO4-3), Ammonium (NH₄⁺) and (pH) satisfied the wastewater standard of Environment Organization of Iran and effluent discharging to surface waters was characterized by high quality on the Water Quality Index (WQI). As the result of the principal component analysis, TH, Fe, TSS, and DO, were the most influential parameters in the first component and SO4-2 in the second component, in measuring the wastewater quality variation. A significant increase from inlets to outlets was observed for (pH), total suspended solids (TSS), total dissolved solids (TDS), phosphate (PO4-3), and total hardness (TH) (p<0.05) due to no effluent treatment processes and intense culture at the fish farms and implies a Wastewater treatment system for removing suspended solids, pH control, and reducing TH and TDS.