The co-dry fermentation of kitchen waste and dried chicken manure is technically feasible
and a potential method for treating these waste fractions and providing bioenergy and
biofertilizer. Co-digestion of chicken manure with food wastes or other wastes would
increase the level of chicken manure AD. Based on this study, dried chicken manure can
be efficiently digested well as a side substrate but not alone due to high nitrogen content.
Chicken manure can be seen as a source of alkalinity and nutrients for nutrient-poor and
easily degradable vegetable-rich kitchen waste rather than a single substrate for AD. Co
substrates are needed for diluting inhibiting agents to avoid excess water use and lower
process efficiency. The nitrogen concentration in the feed should be set to reach nitrogen
contents inside the reactor below inhibiting levels and stay within safe limits to provide a
buffer effect in case of accidents. For a stable process, it is crucial to keep the nitrogen
concentration low. The digestate could be utilized as a fertilizer in soils that require
moderate or no phosphorus supplementation due to digestate’s high nitrogen to phosphorus
ratio.