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INEGI helps optimize the energy efficiency of Portuguese and Galician wastewater treatment plants

28 - 06 - 2019
Of the desire to create an efficient and sustainable energy model for wastewater treatment plants (WWTP), the AQUALITRANS project was born in the northern Portugal-Galicia region. It’s promoted by a consortium which includes INEGI, who is preparing soon to kick off a pilot in collaboration with Águas do Porto.

The project started in 2017 and since then, INEGI has been in charge of studying the energy profile of different WWTPs installed in the North of Portugal, as well as identifying improvement measures regarding energy efficiency and the operational management of the facilities.

The Institutes specialized team collected and analysed information in 23 WWTPs, and carried out a more detailed study of 10 of them, namely those from Sobreiras and Freixo, in the city of Oporto, and the WWTPs in Serzedo, Lamego, Ponte da Baia, Sousa, Penices, Chaves, Vila Real and Barcelos. "By analyzing the energy consumptions of the facilities and evaluating the most energy-consuming processes and equipment, it was possible to identify the necessary measures to increase efficiency," says João Pedro Cardoso, member of INEGI’s project team.

The team determined that the processes that consume the most energy in the WWTP are the inlet or deodorization pumping and the centrifuges for sludge dewatering. The aeration equipment belonging to the biological treatment proved, however, to be the largest energy consumer, sometimes accounting for 50% of the total energy consumption of a WWTP. It was based on this characterization, and on the equivalent study done across the border, that the consortium developed an advanced management tool to evaluate the current state of a WWTP, in energy and operational terms, as well as to compare it to similar facilities.

"This work allowed the consortium to obtain a comprehensive view on the energy consumption of Portuguese and Galician wastewater treatment plants, and it was this information that served as a basis for the creation of these tools and the adoption of measures with application in other facilities," says João Pedro Cardoso.

Now reaching its final phase, the project includes a pilot test at the Sobreiras WWTP, managed by Águas do Porto, and the subsequent evaluation of the resulting energy, operational and economic benefits. As explained by Vânia Morais, responsible for the project at Águas do Porto, "through the AQUALITRANS project, Águas do Porto, E.M. intends to improve the energy efficiency of its WWTP. Our collaboration with INEGI will allow us to improve our plans, to identify measures to be implemented, while also evaluating the result of the application of each one of them”.

The AQUALITRANS project also counts as partners Augas de Galicia, Instituto Enerxético de Galicia (INEGA) and Fundación Instituto Tecnológico de Galicia (ITG).