ANAEROBIC TREATMENT OF THE CENTRIFUGED SOLID FRACTION OF PIGGERY WASTE-WATER IN AN INCLINED PLUG-FLOW REACTOR

This paper reports the experimental results of a 6 months run on a ben ch scale inclined tubular anaerobic reactor treating centrifuged pigge ry sludge at 12-18% TS. The particular reactor design was demonstrated to be appropriate for handling this very dense feed material. Reactor performances were very satisfactory: with increasing loading rates up to 10 g COD.1(-1).d-1 (corresponding to 12 d HRT the organic matter d egradation was always constant around 60%. Methane yield was calculate d around 321 CH4/l raw feed. The effluent was well dewaterable and sho wed low phosphorus levels in the liquid phase. A curious phenomenon of granulation is also discussed.