Optimisation and upgrading of wastewater treatment plant in San Giovanni Lupatoto (Italy)

The project regards the woks of the complete optimization of the existing wastewater treatment plant of San Giovanni Lupatoto, an important and populous town near Verona. At the present time, the discharge directed to the plant corresponds to that of 24,000 equivalent inhabitants. The project envisages the upgrading of the plant to 50,000 equivalent inhabitants.

The principal sections of the plant and the works provided are:

• Initial pumping station: demolition of existing station and re-construction with new geometric dimensions and a new by-pass system with plane gate and ultrasonic system of hydraulic measure;
• Nitrification: this aerobic stage provides the biological oxidation of nitrogen, from ammonia (NH3) to nitrite compounds (NO2). The transformation process is due to the activity of Nitrosomonas bacteria colonies. To complete the biological treatments, Nitrospira bacteria colonies convert the nitrite (NO2) to nitrate compounds (NO3).
• Denitrification: in this stage, anoxic conditions are provided, so that heterotrophic bacteria can convert nitrates to nitrogen gas N2.
• Secondary sedimentation
• Disinfection: in order to discharge back to the environment, the treated water, the removal of micro-organism is provided by disinfection. The effectiveness of disinfection depends on the quality of the water being treated (e.g., cloudiness, pH, etc.), the type of disinfection being used, the disinfectant dosage (concentration and time), and other environmental variables. Ultraviolet (UV) light can be used instead of chlorine, iodine, or other chemicals. Because no chemicals are used, the treated water has no adverse effect on organisms that later consume it, as may be the case with other methods.