Kinetics of methane formation by granular sludge at low substrate concentrations

Summary Apparent K _m values for methanogenesis from volatile fatty acids by various sludge granules were determined from progress curve experiments. The influence of mass transfer resistance on the kinetics of methane formation in biofilms was demonstrated with the apparent K _m values thus obtained. It was shown that the effects of mass transfer resistance depend on the maximum specific activity of the biolayers and on their thickness. the data indicate that mass transfer resistance in methanogenic biolayers becomes only of significance at low substrate concentrations and in thick biolayers with high methanogenic activities.