The effect of biomass separation method on the efficiency of hydrogen production by Platymonas subcordiformis

Platymonas subcordiformis may be deemed a prospective species in terms of its hydrogen production capacity. The efficiency of hydrogen production by these microalgae is affected by the method of sulfur compounds removal from the culture medium, which urges the search for effective separation methods. This study aimed to determine the feasibility of harnessing membrane vacuum filtration (MVF) for P. subcordiformis microalgae biomass separation from the culture medium to boost the hydrogen yield. Its results proved a positive impact of the filtration method on hydrogen production. Higher technological performance due to the use of MVF was recorded in the variants with biomass concentration in respirometers ensured at 5.0 g(ODM)/dm(3). In the most effective variant, hydrogen yield after biomass concentration using MVF reached 156.3 +/- 11.0 cm(3) H-2 at the mean production rate of r = 1.38 +/- 0.1 cm(3)/h, whereas after centrifugation the respective values were at 138.3 +/- 12.8 cm(3) H-2 and r = 1.09 +/- 0.09 cm(3)/h. Hydrogen production efficiency was also found to significantly depend on the initial biomass concentration in respirometers and culture medium composition at the stage of biomass cultivation.

Automated summary

This study determined the feasibility of using membrane vacuum filtration (MVF) to separate P. subcordiformis microalgae biomass and boost hydrogen yield. The results showed that the filtration method positively impacted hydrogen production, with higher technological performance observed in the variants using MVF.