Lausanne-Vidy Wastewater Treatment Plant, Switzerland / New WWTP

Project description

The Lausanne-Vidy WWTP was built in the 50s and was commissioned in 1964. Since then, it only benefited from minor upgrades.

Objectives

New treatment requirements lead to designing a new plant with an extended capacity of 240'000 m3/d, allowing:

• a full nitrification of the wastewater (down to 2 mg NH4/l),
• an advanced treatment of the TSS (0.3 mg/l),
• the treatment of the micro-pollutants (80% yield on the selected indicators)
• the disinfection of the treated water.
• sludge digestion
• biogas purification and reinjection
• energetical optimisation

Such requirements implied a complete renewal of the wastewater treatment process. Besides, the preliminary design foresees the addition of a digestor in the sludge treatment, with the reuse of the biogas.

The proposed site is affected by numerouos constraints, the project plans to build the works inside a compact and closed building, which roof can be used for recreational activities, within the framework of the urban transformation project of the City of Lausanne.

Key project caracteristics

• Design flow 2.4 m3/s for biological treatment, 12 m3/s mechanical
• Preatreatment 3 lignes
• 3 compact high-rate DENSADEG Clarifier/Thickener
• 5 BIOFOR pre-DN filters (140 m2 p. unit)
• 12 BIOFOR N filters (140 m2 p.unit)
• Micropollutant treatment through ozonation, PAC, sand filters
• UV Desinfection
• 2 digesters volume 5000 m3 p. unit
• 3 centrifuges 900 kg MS/h
• Biogas treatment + reinjection

Services

• Project Design and Works for electromechanical equipments for wastewater and sludge treatment.
• Energy planning WWTP and surroundings with LCA (Life-Cycle Analysis)
• Process and hydraulical engineering
• Interdisciplinary and technical coordination
• Works supervision and direction
• Start-up and commissionning