Abstract: Anaerobic fermentation is a kind of effective resource utilizations of algae. However, the carbon-nitrogen ratio (C/N) of algae is low and the methane need to be purified, which are the difficulties for practicality of algae fermentation. Methane production from different blue algae systems and sulfurous gas concentrations were investigated in lab scale. The results showed that the total methane production from system with algae/straw/seed sludge ratio of 8/2/1 was the highest, with productive rate of 176 mL/g(VS). There were different sulfurous gases within the biogas. H2S concentration was the highest, with the maximum value of 14016.12 μL/L during 50 days of monitoring. H2S value was positively correlated with CH4S, C2H6S, C2H6S2 and C2H6S3, which indicated the higher H2S concentration, the higher CH4S, C2H6S, C2H6S2 and C2H6S3 concentrations.

Key words: blue-green algae, methane, carbon-nitrogen ratio, sulfurous gas, correlation analysis