Maximum organic loading rate for the single-stage wet anaerobic digestion of food waste

► Anaerobic digestion (AD) of food waste (FD) was conducted at high OLR for 225 days. ► High CH4 yield and high VS reduction were achieved at high OLR simultaneously. ► The cell density in the sludge increased to 15 times that in the original seed sludge. ► The cell density increased during the periods when there was no organic loading. ► The maximum OLR was estimated around 10.5 kg-VS m−3 day−1 in a single-stage wet AD of FD.