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 (R_{conti,B,disturbed}) but not for the discontinuously fed reactor (R_{disco,disturbed}) in Experiment 1. The continuously fed undisturbed control reactor (R_conti,A) shows no changes in pH and VFA concentrations