Pilot scale tests on anaerobic co-digestion of vegetable tannery sludge and fleshing

The Italian tannery industry produces 9% of the global and 73% of the European bovine leader. One of the most important districts is located in the area surrounding Florence and Pisa, in Tuscany. Fleshing and tannery sludge are typically treated separately and sent to land application. In a typical (complete) tannery process fleshing production is about 25% of the sludge generated from wastewater treatment and represents a potential resource for bioenergy production. In this work, the efficiency and the technical feasibility of anaerobic co-digestion of vegetable tannery industry primary sludge (VTPS) and fleshing was investigated. Tests were conducted under mesophilic conditions in two pilot scale (150 L) reactors.