Milan is the second most populous city in Italy, following Rome, with a metropolitan area that is home to over 3.2 million inhabitants.
Metropolitana Milanese S.p.A. (MM Spa) is responsible for managing the water services in Milan, including groundwater intake, purification, distribution, wastewater collection, treatment, and the overall maintenance and investment planning for the water supply and wastewater networks.
The groundwater in Milan is contaminated with chemical solvents and nitrates. To address this issue, a new drinking water treatment facility located on Via Feltre has been established to treat the contamination. Suez, working on behalf of MM Spa, has chosen a process based on biological nitrate filtration for this purpose.
Biological denitrification: a reliable solution for drinking water treatment
Biological denitrification involves the biological oxidation of organic substrates in water treatment using nitrate or nitrite as the electron acceptor instead of oxygen. In a drinking water treatment plant, denitrification is carried out in just one step inside an anaerobic bio-filter filled with the filter media Filtralite Pure, which is the optimum carrier for the denitrification biofilm. The system is simple to design, very reliable, highly performant, and has a low operational cost.
Nitrazur®, a Suez-patented process, works with a vertical flow and specific underdrains, and the biofilm develops on Filtralite Pure HC 2,5-5. This Filtralite solution offers an important specific surface area and allows a drastic removal of these pollutants.
360 m³ of Filtralite Pure HC 2,5-5 were shipped from Norway to Milan in big bags. The plant is located downtown; therefore, storage and implementation constraints were important. We worked with a specialised service provider (Palm Environnement) to install the products with hydro-ejectors in a complex configuration.
