ABSTRACT
The effect of the composition of the culture medium and the variation of the substrate/microorganism ratio during the development of anaerobic biodegradability test was studied. An automatic monitoring system was developed for continuous and parallel monitoring of nine reactors measuring the pressure generated by the biogas produced during the anaerobic biodegradation of the substrate. With this system, the experimentation was carried out in serum bottles at 35°C with anaerobic sludge acclimated to ethanol. The influence of three different culture media as well as the effect of the initial substrate concentration to the initial biomass concentration ratio, So/Xo, on the extent of anaerobic biodegradability was studied. It was observed that the composition of the medium has an important influence on the results. The degradation rate of substrate increased when the So/Xo ratio increased (under agitation). Because of that, it is necessary to make an effort to unify criteria including media composition and So/Xo ratio to achieve a possible standardization of the test.
