Performance Evaluation of a Facultative Aerated Lagoon for the Purpose of Reviewing the Design Parameters

Evaluating the performance of a facultative aerated lagoon in a semi-humid region in Iran shows that the design parameters, which were derived from foreign references, used for dimensioning these types of wastewater treatment facilities, do not match the real values. A study conducted by Moradhasseli and Mohamadi proves that the design procedure, including choosing the initial design parameters has affected the performance of wastewater treatment plants in Iran [1]. S.R. et al. reported that the need for determining the exact values of qualitative and quantitative parameters for new design is obvious [2]. Of The need to review those parameters to achieve a more realistic and cost effective design is therefore obvious. In addition to suggesting more reasonable design parameters which may be of benefit while dimensioning these plants in Iran, computing the overall BOD removal rate based on the real qualities of the wastewater, which can be used in a theoretical approach for dimensioning, ensures a more accurate design compared with a design based on an assumed detention time as is currently usual in Iran. Accurately designing the facultative aerated lagoons widely used in Iran leads to cost savings because of decreasing the dimensions of the downstream lagoons, thus the obligation to apply the real quality parameters obtained in this study in new designs is proved.