Start up of anaerobic digestion of tomato processing wastes for methane generation.

A good start-up of digestion of tomato-processing waste (TP W) was achieved
by the stepwise addition of feedstock over 10-12 weeks of digestion. The
stepped increases of TP W in the digester resulted in a steady-state gas yield of
0.597m3/kg VS added with a 72% methane content. Volumetric production
of gas and methane remained high after the eighth week of digestion
throughout the investigation. The volatile fatty acids concentration in this
system was similar to a cowdung-fed digester and never exceeded more than
150mg/litre throughout the period