The upgrading of treatment plants and related technologies, have significantly reduced the amount of excess sludge to dispose of. Throughout the past 20 years the excess sludge production drop from 180.000 ton/y on 1995 to 15.000 ton/y on 2015. Despite of this, the massive flows still remain huge and the landfil disposal has shortly showed objective problems connected, firstly, to the volumes needed by this kind of solution. As a consequence of this, an alternative method has been studied, which would reduce the overall volume of excess sludge and allow its reuse as recover second raw material MPS at the same time, closing, this way, a virtuous recycle started from a waste.
The Ecoespanso s.r.l. plant was built in 2001 for the purpose to solve the environmental issues related to the excess sludge landfill disposal, in order to improve the environmental sustainability of the whole tanning process.
Since July 2014 Consorzio Aquarno has been managing the Ecoespanso plant and it has carried out some little rearrangements, also due to new synergies between two plants and their needs.
Ecoespanso premise is almost fully dedicated to the treatment of Consorzio Aquarno's excess sludge, whose production, since June 2013, has been increased significantly, due to felt of Consorzio Conciatori di Fucecchio under Aquarno control. The final product of Ecoespanso's process is the sintered granules (KEU) which is usually mixed with Calcium Carbonate to make the filler mixes HSC and HBC. The first one is used as component for the production of cement, while HBC could be used for the production of asphalts.