Four types of hydrolysis kinetics were tested for anaerobic degradation of complex organic matter using the generalized simulation model described earlier The simulation dynamics from all types of hydrolysis kinetics of swine waste, sewage sludge and cattle manure for continuous-flow reactors at a defined SRT fitted the experimental data comparatively well. However differences were found for particulate organic matter degradation over a wide range of SRT values. For that case a model of hydrolysis kinetics including a surface colonization of the particles by hydrolytic bacteria, as well as a following surface degradation, was developed. Copyright (C) 1996 Elsevier Science Ltd.