Steady State Model of Solid-State Anaerobic Digestion of Dewatered Sludge Under Mesophilic Conditions

Solid-state anaerobic digestion of dewatered sludge was investigated under mesophilic conditions and a steady state model was developed to help reactor design for solid state anaerobic digestion system of dewatered sludge. Biogas yield, volatile solid reduction and methane content showed good linear relationship with OLR (or 1/SRT) at long SRTs (≥ 10d). The minimum SRT at which system failure occurred was 3 days. Maximum VS reduction and biogas yield was estimated 44.83% and 0.420 l·g-1 VSadded-1d-1. First order constant k was 0.24 d-1. The model can be used to predict system performance and help reactor design.