Nordic microalgae cleans wastewater and produces biodiesel

Green microalgae are photosynthetic water organisms that use sunlight and a few other nutrients to transform CO2 into energy and biomass. Algae biomass is considered a good raw material for the production of biofuels, as these microorganisms can naturally form and store large amounts of lipids, which in turn can be converted into biodiesel.

In addition, the nitrogen and phosphorus found in municipal wastewater can be recycled to feed the microalgae, which means that the same process can be used for biomass production and sewage treatment.

However, the use of microalgae is very limited in countries up north, where the long winters are characterised by few hours of daylight and low temperatures that limit growth. In her thesis, Lorenza Ferro shows that the use of indigenous Nordic algae strains, which are naturally adapted to the tough environmental conditions in these parts, can be a solution to successful microalgae farming in the region.

Several Swedish microalgae strains that were able to grow in municipal wastewater were isolated and genetically classified. Eight strains were characterised on the laboratory scale as very effective in removing excess nutrients from wastewater; four showed signs of rapid growth, a high biomass production and lipid content; three of them also gave proof of effective adaptation to low temperatures or conditions with limited access to light.