Mixed culture model of anaerobic digestion: application to the evaluation of startup procedures

The successful operation of anaerobic digestion depends on the balanced growth of many bacterial species. The functions of the main groups of microorganisms present in a digester have been analyzed and a mathematical model constructed that describes the interactions among the microbial populations and their effect on the digester performance. The model was validated by comparing its predictions with actual digester operation. Several startup procedures were evaluated in the light of the model predictions and improvements on current operational practices suggested in order to minimize startup time.