Fig. 3

Effect of disturbance in Experiment 1. a pH values over the whole course of the experiment and b total VFA concentrations in the disturbance phase. Process disturbance led to failure of the continuously fed reactor (Rconti,B,disturbed) but not for the discontinuously fed reactor (Rdisco,disturbed) in Experiment 1. The continuously fed undisturbed control reactor (Rconti,A) shows no changes in pH and VFA concentrations