Mechanical screening
(4 screens with a width of 1.8 m)
Primary treatment through lamellar settling with sludge recirculation and integrated sludge thickener (Densadeg) with 4 square sedimenta-tion tanks, preceded by alum coagulation and flocculation, operated in physicochemical mode (the largest sedimentation tanks of this type in the world at the time of their commissioning).
Aerated grit and grease removal (4 aerated grit removers, including 2 bridge crane-activated grit removers)
Secondary treatment through biofiltration (Bicarbonate) with a downward flow (the largest biofiltration of this type in the world at the time of its commissioning)
Ultraviolet disinfection with a medium pressure mercury vapour lamp system and a UV intensity modulation system (the first installation of this type in Québec).
Sludge Treatment:
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Possibility of liquid lime preconditioning at the time of storage.
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Dehydration with two filter presses to obtain a dryness superior to 40%.
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Quicklime conditioning.
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Disposal of sludge through their reuse.
SERVICES RENDERED
Preliminary studies of the treatment sub-sectors
Design of wastewater treatment infrastructures
Calculations and selections of equipment
Project management
Drawings and specifications produced in various construction lots for water treatment, instrumenta-tion and control works
Construction services
Drawings and specifications for ultraviolet disinfection works
Computer monitoring and modifications to programming since 1991
PROJECT DESCRIPTION From 1988 to 1991, the project comprised of the construction of the biofiltration type treatment plant capable of treating the sometimes diluted waters from the Sherbrooke sewer network (combined sewer sectors).
In 1995-1996, UV disinfection was added following a request by MDDEP/MAMR, in order to offer an increased protection to users of the St-François River.
