Responsible partner: VEOLIA and CARTIF

Type of feedstock: Industrial waste water

Nutrients recovered: Nitrogen and Phosphorus

Process technologies: Hybrid system of Photoautotrophic and heterotrophic microalgal cultivation or Microbial Fuel Cell


WalNUT hybrid system proposes a new combination of autotrophic growth in the first stage followed by a heterotrophic mode that will simplify the treatment and save space, being able to use a conventional bioreactor. Moreover, the use of scale-up Heterotrophic biorreactor is a weather-independent operation and enables significant savings in scale-up time and footprint dedicated to the treatment process.

The technology consists of three main stages, (i) microalgae cultivation in two stages, which consume the organic matter and nutrients contained in the waste water; (ii) harvesting or separation phase to recover the solid fraction of microalgae as high-value by product and the liquid fraction as reusable water in the process; (iii) a drying stage by spray dryer to recover the dry microalgae.

The system will be placed in a container for the easy portability and will be energy self-sufficient with solar energy from a photovoltaic system on its top.