N-Butyrate catabolism in the treatment of a semi-synthetic landfill leachate on anaerobic filter under sequential feeding conditions. ------------------------------------------
Résumé
Calculations of the kinetics of volatile fatty acids removal in an anaerobic filter showed that methane production from n-butyrate was not consistent with β-oxidation when the reactor was operated under sequential feeding conditions. Under these conditions, n-butyrate might be anaerobically catabolised by decarboxylation. Iso-butyrate was formed at about 25% of the total amount of n-butyrate removed. After 13 days of continuous feeding, the material balance was consistent with the β-oxidation mechanism and the formation of iso-butyrate became negligible. N-butyrate decarboxylation may therefore be a transient catabolic pathway, although the reason why decarboxylation is preferred to β-oxidation under conditions such as sequential feeding is not clear. Results of similar experiments on acetate removal were consistent with theoretical expectations under conditions of both sequential and continous feeding.