For aquaculture:
Selling feed production units

Microalgal biomass is a high-nutrient material whose protein content reaches 40–70 wt%, and research into it as a sustainable substitute for fishmeal and fish oil is advancing^[1][2]. It contains amino acids, ω-3 polyunsaturated fatty acids, carotenoids and vitamins, and effects on growth, immunity and pigmentation in bivalves, crustaceans and larval or juvenile fish have been reported^[3][4].

Novelgen’s Algal Bloom Capture keeps a library of the optimal species for the characteristics of the water being treated (seawater or freshwater, temperature, pH), so that Bloomo can provide a continuous high-density supply. Work under the SBIR Phase 3 programme has led to test shipments of Bloom Oyster, and the product is now at the market-supply stage.

The biomass processing unit now in development combines solid–liquid separation, drying and particle sizing, and is designed so that feed can be processed on site.

Only algae grown in water suitable for feed production, such as aquaculture water, are used for feed. Biomass grown in sewage or industrial wastewater is not used for feed and is intended for biochar, fertilizer and similar uses. All uses are subject to analyses such as heavy metals and pathogens, and to compliance with the relevant Japanese laws on feed safety and fertilizer quality.

Turning oyster shell calcium carbonate into a resource: we are developing LCA and MRV methodology to assess and trade oyster shells (a by-product of oyster farming) as a resource rather than as industrial waste. Shell calcification also releases CO₂, and studies differ on whether shell carbon can count as a sink. Even when shells are used as a concrete admixture or soil amendment, whether they could lead to credits or other value will be judged only after an LCA of the net balance, including calcification, and of how long the use lasts.

Biochar from algal biomass: pyrolysing the recovered biomass into biochar is thought to store part of the carbon for a long time (how long depends on conditions). Beyond its function as a soil amendment, adding it to constructed wetlands and sewage treatment processes has been reported to suppress N₂O emissions^[5][6].

Conventional biological treatment (nitrification and denitrification) releases much of the nitrogen to the atmosphere as N₂. Microalgae instead assimilate NH₄⁺ directly into amino acids and protein, so the aim is to recover most of the nitrogen as biomass. The nitrogen balance, including N₂O from the algae themselves and ammonia volatilisation, will be checked in demonstration. Together with phosphorus, a resource at high risk of depletion, wastewater could become a source of raw material for nitrogen and phosphorus fertilizer (this requires analyses such as heavy metals and compliance with Japan’s fertilizer law).

In continuous systems using a photobioreactor (PBR) with membrane separation (MPBR), nitrogen removal efficiency > 90% and phosphorus removal efficiency > 90% have been reported in several academic studies^[7][8].

Related: resource recovery at sewage treatment plants