Wastewater treatment plant (WWTP): benchmarking analysis and aeration optimization.

The presented work takes in account two aspects of one of the Italian most bigger civil waste water treatment plant based on conventional active sludge technology (CAS). The first investigation regards the definition and calculation of three indexes of energy consumption. Then, with gathered values, a benchmarking analysis was conducted to compare the SMAT plant with similar ones all around the world. The initial investigation was also used to check which part of the plant uses more electricity. As expected, the aeration system the oxidation tanks is the system in the plant that determines the highest energy consumption, therefore in the second part of the work, the optimization of the aeration operation, from an energy point of view, was performed. A numerical model, for the determination of the system oxygen demand that takes in consideration several function variables, was realized and used with real data coming from two measurement campaigns. The sampling campaigns were performed for a week in two different periods of the year, the warmest and the coldest, then the data were also compared from the ones stored inside the SCADA system of the plant, for further correlations and evaluations. In this work the results obtained from these investigations are presented.