Anaerobic Treatment of the Centrifuged Solid Fraction of Piggery Wastewater in an Inclined Plug Flow Reactor

Abstract

This paper reports the experimental results of a 6 months run on a bench scale inclined tubular anaerobic reactor treating centrifuged piggery 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 degradation was always constant around 60%. Methane yield was calculated around 321 CH4/l raw feed. The effluent was well dewaterable and showed low phosphorus levels in the liquid phase. A curious phenomenon of granulation is also discussed.