The increase in production and change in type of wastewater of the Gusparo Backery S.p.A. affected the efficiency of the existing activated-sludge treatment plant, type SBR, which was realised in the 90s.In particular, the increase in the concentration of greasy in wastewater, due to the installation of a new pasteurisation unit was creating significant difficulties.
We installed, before the activated-sludge plant, a dissolved air flotation system to remove fats and flours present in wastewater. Relieved of these contaminants, the existing treatment system could function perfectly again. Moreover, the new sludge system allowed to discriminate the type of excess sludge for disposal (sludge from the flotation system and biological sewage plant) resulting in a notable reduction in the relevant costs. A period of piloting with a provisional flotation unit preceded this operation.