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Saltgae develops microalgae technology as sustainable alternative for wastewater treatment


The treatment of saline wastewater represents a challenge for many industrial sectors because of the presence of organic content. Businesses devoted to the production of canned fish, meat processing, pickled vegetables, leather tanneries, aquaculture and all kind of brined products generate saline wastewater, and experience high costs in complying with EU directives.

This kind of saline wastewater, with high concentrations of biodegradable organic matter, suspended solids, nutrients (mainly nitrogen and phosphorus) and salt (concentrations up to 15%), is extremely difficult and expensive to treat, and its discharge represents a major threat to the environment e.g. salinity can cause eutrophication of water, and salinization and sodification of the soil.

To address this, the SaltGae project aimed to develop and demonstrate a techno-economically viable solution for the treatment of saline wastewater. Its suite of technologies, combining aerobic and anaerobic processes with ponds hosting synergistic mixtures of halotolerant bacteria and algae, treated wastewater saline effluents resulting from three different production processes.

Main results: 

The SaltGae project has demonstrated its modular technology at three pilot sites, where it achieved the following impacts:

  • Water and wastewater treatment, including recovery of resources equivalent to a cost saving of >59%. In addition the SaltGae solution allows recovery (>90%) of the energy and nutrient content of the wastewater targeting reuse onsite to off-set treatment costs and conversion to value product streams, enabling a further >25% reduction in treatment costs.
  • Water Reuse and Recycling as an important process step of the SaltGae process is wastewater desalination (reverse osmosis and/or electro dialysis).
  • Water Energy Nexus allows recovering energy from the wastewater and reducing energy demand by 50 – 60% compared to existing technologies.