Fig. 3From: Process upsets in a full-scale anaerobic digestion bioreactor: over-acidification and foam formation during biogas productionTime course of ratios of wet analytical data (a) VFA/TIC, VFAS/Ca and VFAS/Mg; (b) phosphor, P/Ca and propionate/acetate; (c) VFAS/P and VFAS/S) as possible EWIs for AD process upsets. For the reason of better clarity, the daily CHP-output (corresponding to the daily biogas production) and VFAS concentration is shown in all three graphicsBack to article page