Anaerobic Co-Digestion Of Tannery Fleshing With Tannery Primary Sludge And Municipal Sludge

The efficiency of anaerobic co-digestion of Vegetable Tannery industry Primary Sludge (VTPS), Vegetable Tanning Industry Fleshing (VTIF) and Conventional Domestic Primary Sludge (CDPS) was investigated. Two sets of batch experiments were conducted using Oxitop equipment, at mesophilic temperature (35°C). The process efficiency of treating VTPS:CDPS was evaluated in the first set (0:100; 20:80; 40:60; 60:40; 80:20, 100:0; volumetric ratio), while the second set aimed to assess the feasibility of the co-digestion of VTPS:VTIF (1:2, 1:1, 2:1; in terms of volatile mass content). Our results show that in the anaerobic digestion the observed specific biogas production was 0.377-0.225 m3BG kg-1VSS,rem, at different VTPS:CDPS ratios. For co-digestion tests of VTIF:VTPS, the highest value of 0.695 m3BG kg-1VSS,rem being for a VTPS:VTIF 1:2 ratio. Despite the high ammonia content and the requirements for long hydrolysis, fleshing proved a valuable substrate for VTPS co-digestion, without exhibiting inhibition.