Anaerobic co-digestion of swine and poultry manure with municipal sewage sludge

- Sewage sludge co-digested with swine and poultry manure.
- Mixture of sludge with swine manure gave the highest biogas production.
- Volatile solids reduction was moderate to low.
- Ammonia inhibition occurred when treating sludge with swine and poultry manure.
- Low efficiency in pathogen inactivation.

The anaerobic digestion of municipal sewage sludge (SS) with swine manure (SM) and poultry manure (PM) was undertaken. It was found that a mixture of sewage sludge with a 30% addition of swine manure gave around 400 dm3/kgVS of biogas, whereas the maximal biogas yield from ternary mixture (SS:SM:PM = 70:20:10 by weight) was only 336 dm3/kgVS. An inhibition of methanogenesis by free ammonia was observed in poultry manure experiments. The anaerobic digestion was inefficient in pathogen inactivation as the reduction in the number of E. coli an Enterobacteriaceae was only by one logarithmic unit. A substantial portion of pathogens was also released into the supernatant.