From Problem to Product - Nutrient Capture by Microalgae

Purpose and goal

The aim of this project was to convert waste and residuals such as wastewater and flue gases into valuable products in an environmentally sustainable way. North-Swedish microalgae were grown on local wastewaters and flue gases to produce biomass. The microalgal biomass has been chemically characterized; then it has been successfully used for the production of biofertilizers and biochar. A feasibility study using standard methods, such as the Business Model Canvas, has been performed.

Expected results and effects

Single local algae isolates and a natural polyculture grew very well in urban wastewater with the addition of flue gases. Microalgal biofertilizer was well suited as replacement of conventional nutrients in cultivation of microorganisms, such as a filamentous fungus that has large potential as fish feed. The residue was used for biochar production. Microalgal biofertilizer worked also very well for cultivation of forest tree seedlings. These results have clear positive environmental impacts.

Planned approach and implementation

Local microalgae isolates and a natural polyculture were grown in urban wastewater with addition of flue gases (WP1). The algal biomass was chemically characterized and provided to WP 2 and 3. In WP2, the microalgae were fractionated to a nitrogen- and phosphorus-rich biofertilizer and a residue, and trials with biofertilizer were conducted. In WP3 biomass and residue were used for the production of biochar using HTC. WP4 performed a feasibility study with the data generated in the project.