E2 Sewer tunnel

Client: YIT Sverige AB

Assignment: Water purification regarding minimization of particles and pH adjustment according to current emission requirements.

Scope: This assignment includes three treatment systems located in three separate locations along the tunnel. The systems perform minimization of particles in the water at all locations and adjust the pH so that treated water meets the authorities’ current discharge requirements. Particle purification is performed by automatic dosing and mixing of precipitating chemicals that increase the particles’ tendency to settle. The particles are collected as a sludge, which can be easily removed and taken care of. The pH is regulated by automatic dosing of carbon dioxide, both an efficient and economical method.