Microcalorimetry was used for monitoring anaerobic digestion processes of heavily polluted industrial waste waters (from cheese
industry, distilleries, yeast plant). Interpreting the thermal power-time curves by HPLC, some sub-processes in batch cultures
were tentatively identified as acidogenic, acetogenic and methanogenic. Processes underlying power-time curves up to 10 h
were different for different wastes. In the case of cheese whey and distillery waste it was acidogenesis, in the case of sulfate
containing waste - presumably reduction of sulfates. The effect of Biotreat 100 (BimKemi Eesti Ltd.), a preparation for removing
H2S from waste water, was observed for these processes.