The wastewater from the paper mill is treated using a combination of physical-chemical and biological processes.
- Physical-Chemical
This is the process performed by the Sedimat treatment unit, which operates on the principle of using substances that promote the coagulation of the solid particles in the wastewater, which are then deposited on the bottom of the tank ready for collection.
The so-called 'sludge', or mass of precipitated particles, is mechanically pressed and dried and almost totally used for the production of bricks (94% - Figures 2005). - Biological
In 1997 Cartiere del Garda activated a new biological treatment unit called Biofor patented by Degremont, a French company that is one of the world leaders in the field. This unit, which complements the existing physical-chemical unit, is considered a model for the whole Italian paper industry. The technical know-how used resulted in a vertical unit which saved 80% of the surface area required by a traditional biological treatment unit of equal capacity.
The heart of the unit is its colonies of bacteria in expanded clay granules. When they come into contact with wastewater these bacteria metabolise the pollutants in an aerobic process that produces absolutely no smells at all.
Biofor is an innovative solution primarily because of its capacity to guarantee high purity values of its discharged water, which empties directly into Lake Garda.
