The Consorcio de Aguas Bilbao Bizkaia (CABB) has given the green light to a project to cover and implement odour control in the biological treatment section of the Galindo Wastewater Treatment Plant (WWTP) in Sestao. The tender procedure for the project will commence this month. The project, which has a budget of 7,853,976 euro, seeks to reduce the visual and odour impact associated with this section of the plant. It includes renovation of the infrastructure and the electromechanical equipment, which are now 20 years old. The initiative has been conceived as a pilot test. For the purpose of the test, Reactor 4 at the plant will be used and the project will serve to confirm if the chosen alternative can be applied to all the ponds at the plant.
This project to cover and implement odour control in the bioreactor will be carried out in an area of settling ponds at the WWTP with a surface area of 25,400 m2. This area houses six blackwater ponds (responsible for 6.3% of odours emitted from the facility) in which organic matter and ammonia is removed by means of an activated sludge process. The decanted water is sent to the reactors, where the bacteria of which the biomass is composed degrade the organic matter and ammonia. These six reactors have a volume of 210.000 m3.
The project will be carried out on Reactor 4. After completion of the work, scheduled to take 24 months, the adopted solution will be analysed for a further 12 months to determine its efficiency in terms of impact reduction and also to determine if the covering system structure and the construction process is suitable for replication in the remaining reactors within the shortest possible time period. The solution is technically innovative, attractive and original and has before never been implemented at a WWTP of these characteristics in Spain.