The following works were carried out as part of the intervention:
- a new activated sludge line of the integrated two-stage oxidation/nitrification predenitrification type in parallel with the existing one; the additional line will have a volume of about 1,120 m3 for the predenitrification compartment and about 2,510 m3 for the oxidation/nitrification compartment; the line will be equipped with an autonomous sludge recirculation station;
- The upgrading of the existing activated sludge line from an oxidation-nitrification plant type to an integrated two-stage oxidation-nitrification predenitrification plant type by compartmentalizing the two existing basins with r.c. baffles and constructing hydraulic circuits for recirculation of the aerated mixture;
- The upgrading of the air production system by installing an additional blower (of higher capacity) in parallel with the two existing ones;
- The construction of a centralized lift for predenitrification recirculation of the aerated mixture.
