ANAEROBIC CO-DIGESTION OF SOURCE SELECTED ORGANIC WASTE AND SEWAGE SLUDGE

The paper is concerned with the anaerobic co-digestion of wastewater treatment
plant sludge and organic waste coming from the fresh food department of a large market store
where a source separated collection system is installed. In particular the study is aimed to verify
– by means of pilot plant operation – if the reactor is able to work in stable conditions for
increasing organic loading rates – due to the organic waste addiction – with respect to the
wastewater sludge simple digestion. In this way, different organic loading rates were tested,
which corresponded to different scenarios of organic waste feeding to the anaerobic digestion
plant. For the carried out experiments the pilot reactor showed a considerable improvement in
biogas production while the reactor working conditions remained stable. An economical analysis
– based on energy recovery assumptions – was carried out for each tested scenario, evaluating the
specific industrial treatment cost for the considered organic fraction.