Laboratory Algae Cultivation and BMP Tests with Ulva intestinalis from the Gulf of Riga

The cumulative CH4 yields show an important spectrum of cumulative methane yields, with the highest one observed in 1:3 A/I (algae/inoculum ratio) in which the macroalgae were chopped (92.1 ± 33.5 mL CH4/g VS on average), while the lowest one was observed in 1:5 A/I where the macroalgae had no pre-treatment (36.0 ± 10.5 mL CH4/g VS). The results do not show a clear impact of the pre-treatments. The scenarios with no pre-treatment exhibited the effectiveness in a range of 9.7-24.6%, while the chopped ones - 14.56-24.8%, pre-treated with pestle - 12.9-24.13%. The results of this study confirm the suitability of U. intestinalis for biogas production, especially in the Baltic region.