Abstract
Control and monitoring of water sources from different types of contaminants especially collection and proper wastewater discharge is very important, in Iran which is considered as one of the dry regions in the world. Undesired quality of wastewater treatment plant's (WWTPs) effluent causes many environmental problems. In this research the parameters of Biochemical oxygen demand, Chemical oxygen demand, Total solids, Total suspended solids, Total dissolved solids, Potential of Hydrogen, Mixed liquor suspended solids, Mixed liquor volatile suspended solids, Sludge volume index, and temperature are examined based on the book of Standard Methods. The results of analyzing the above parameters which are related to eight WWTPs effluent out flow in Tehran, were analyzed by SPSS and Excel soft wares. The achieved data were compared to the standards of Iran's Environmental protection agency. The results has shown that the parameters of Potential of Hydrogen, Chemical oxygen demand, Biochemical oxygen demand, and Total suspended solids of WWTPs effluent in Tehran are in accordance with standards of Environmental protection agency which are respectively 97.5%, 95.8%, 96.1%, 68.8%. WWTPs of C has also the best operation among other WWTPs. In this study, due to ethical considerations, the name of the WWTPs is not mentioned. The names of the WWTPs are marked with A-H.