Decontaminating industrial effluents using microalgae


Industrial effluent treatment: a pioneering solution reduces nitrogen concentration by 97% in 24 hours thanks to microalgae.

Planctonid Environnement, a biotechnology company specialising in the cultivation of microalgae, has developed a totally innovative technology ("bioremediation") to decontaminate industrial effluents highly charged with nitrogen and phosphorus, using microalgae. Egis, via its teams specialising in water treatment engineering, contributes its full expertise to the development of this solution (regulations, engineering, optimisation, robustness of the solution).

A pilot site in Saint-Nazaire (Loire-Atlantique), in partnership with Yara France

Using a high-yield microalgae production technology, the solution developed by Planctonid allows effluents highly charged with nitrogen and phosphorus to be efficiently treated and a usable biomass to be produced.

The microalgae consume the nitrogen and phosphorus from the effluents together with CO2, and produce, through photosynthesis, a usable biomass with high protein and essential amino acid content. The biomass produced then has potential outlets in animal feed, green chemistry and biostimulants, thereby opening up prospects for circular and positive impact economies.

To demonstrate its effectiveness, a pilot project has been set up in partnership with Yara France, the world leader in fertiliser production, at its Montoir-de-Bretagne (Loire-Atlantique) plant. Through this pilot, and in collaboration with the Grand Port Maritime de Nantes-Saint-Nazaire, Yara France aims to mass-treat its industrial wastewater, in a spirit of industrial ecology.

Initial results that surpass expectations!

The results of this first phase are extremely positive and even exceed expectations: the process manages to reduce nitrogen and phosphorus concentration levels by 97% and 72%, respectively, in less than 24 hours, while maintaining high biomass productivity.

The process has demonstrated its flexibility and biological robustness by successfully treating input water with varying levels of phosphorus and nitrogen concentration.

Egis, in close collaboration with Planctonid, is monitoring the project in order to consolidate the overall installation that will be built following the pilot scheme (regulations, process optimisation for future use of biomass, control of construction costs and optimisation of operating costs).

A commitment to promote circular solutions

The preservation of our resources, our environment and our health are the major challenges of our societies. The solution developed by Planctonid with the support of Egis addresses major issues, particularly in terms of environmental protection:

Fighting the imbalance of marine, coastal and inland waters: biologically purifying industrial and urban wastewater, tertiary treatments (elimination of ammoniacal nitrogen, nitric and nitrous compounds and phosphorus).

The fight against greenhouse gases: each tonne of microalgae biomass produced consumes 1.8 tonnes of CO2.

By joining forces with Planctonid, Egis displays its commitment to promoting innovative biological solutions aimed at fostering a circular economy through a fully integrated approach to the problems encountered by its clients.

The aim is to go beyond the simple constraint imposed by regulatory compliance to propose systems that not only address the problems posed but also provide added environmental, societal and economic value.