Algal Bloom Capture (ABC)
A technology that controls algal blooms (the mass proliferation of microalgae) inside closed units, taking up CO₂ by photosynthesis while recovering nitrogen and phosphorus from wastewater as biomass. The net greenhouse-gas reduction, including how the biomass is used (feed, fertilizer, biochar and so on), will be assessed by LCA in line with ISO 14040/14044.
CO₂
Uptake
Taken into biomass by photosynthesis
N・P
Nutrient Recovery
Nitrogen and phosphorus assimilated by algae
LCA
Net Impact
Net reduction assessed by LCA
How ABC works
Cultivate & Control
We pick a strain suited to the water from our library; IoT and AI control light, temperature and nutrients to grow a dense culture.
Take up CO₂ & nutrients
Photosynthesis takes up CO₂ while nitrogen and phosphorus are assimilated into cells. CO₂ can come from air or flue gas.
Recover Biomass
Harvest at the target density and separate the algae from the treated water. Environmental effects are assessed by LCA.
Reuse
Uses (feed, fertilizer, biochar and so on) depend on the source water and regulations. Sewage-derived biomass is not used for feed. How carbon could be credited is still under study.
Restoring three cycles
The three cycles ABC works on: carbon, nitrogen and water
CO₂ is taken up by photosynthesis. Carbon used as feed or fertilizer returns to the air within a short time, so long-term storage (biochar, for instance) is under study and the net balance is assessed by LCA.
NH₄⁺ is assimilated into amino acids in algal cells, aiming to recover most of the nitrogen as protein. This should release less N₂ and N₂O than nitrification–denitrification, but the balance, including N₂O from the algae themselves and ammonia volatilisation, will be checked in demonstration.
Nitrogen and phosphorus are taken up by the algae, aiming at purification that does not rely on aeration (nitrification) and denitrification. The algae are separated from the treated water before discharge.
Where it applies
Aquaculture
Live feed supply and water quality management for shellfish and crustacean farming
Water treatment
Recovering nitrogen and phosphorus from wastewater (research stage)
Agriculture
Algal biomass as a fertilizer feedstock (research stage)
Using flue gas
Using CO₂ in flue gas from plants and power stations for cultivation (research stage)
The evidence behind it
Algal Bloom Capture (ABC) is Novelgen’s own technology, combining mechanisms reported in the peer-reviewed literature: photosynthetic CO₂ uptake by microalgae, assimilation of nitrogen and phosphorus, and nutrient recovery from flue gas and wastewater. The figure of about 1.83 t CO₂ per tonne of biomass (dry weight) is a stoichiometric value that assumes carbon makes up 50% of dry weight. It is gross uptake, not a net reduction after the emissions from electricity, harvesting and drying. Carbon in biomass used as feed or fertilizer returns to the atmosphere within a short time, so the net reduction will be assessed by LCA. Microalgae themselves have been reported to produce N₂O under some conditions, and the nitrogen balance will also be checked in demonstration. Treatment rates, yields and removal ratios vary with the deployment environment and the strain or blend, so representative figures are shared as our own demonstration data under a non-disclosure agreement.
References
- Mohsenpour S.F., Hennige S., Willoughby N., Adeloye A., Gutierrez T. Integrating micro-algae into wastewater treatment: A review. Science of the Total Environment, 2021, 752, 142168. DOI →
- Cheah W.Y., Show P.L., Chang J.-S., Ling T.C., Juan J.C. Biosequestration of atmospheric CO₂ and flue gas-containing CO₂ by microalgae. Bioresource Technology, 2015, 184, 190–201. DOI →
- Clarens A.F., Resurreccion E.P., White M.A., Colosi L.M. Environmental life cycle comparison of algae to other bioenergy feedstocks. Environmental Science & Technology, 2010, 44(5), 1813–1819. DOI →
- Plouviez M., et al. The biosynthesis of nitrous oxide in the green alga Chlamydomonas reinhardtii. The Plant Journal, 2017, 91(1), 45–56. DOI →
Deployment and joint research
Detailed materials on ABC are available under a non-disclosure agreement. Please get in touch.
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