The role of formate in the anaerobic baffled reactor

The anaerobic baffled reactor (ABR) contains a mixed anaerobic culture segregated into compartments. During pseudo-steady state runs, formate was detected in the first two or three compartments, thereafter dropping off sharply. Under conditions of shock loading, formate was detected in the reactor effluent, up to peak concentrations of 2500 mg/l. There are indications that formate may play an important role as an intermediate in the anaerobic digestion process, and that its production may contribute significantly to reactor stability.