Can algal biomass be produced from wastewater?

Wastewater is not only a waste anymore. It can be also a considerable source of nutrients to establish more cost-efficient cultivation of algal biomass. Algae can grow efficiently in the wastewater as they are capable of the nutrient recovery from various sources. In algal wastewater treatment systems, the remaining water can be safely returned into the environment, recycled back to the technological processes, or used for the irrigation in agriculture. Their biomass can be further exploited as a secondary raw material to produce fertilisers, animal feed, biofuels or the higher-added-value products like agricultural biostimulants.

To make algal cultivation on wastewater truly viable, production optimisation and adaptation must be done at the large scale. As the algal community largely establishes by itself in the open ponds, waste stream application procedure and harvesting regime can be adjusted to achieve the highest production and cells’ composition for the most advantageous biostimulative effects on the agricultural crop. Operation regime must additionally consider the climatic variations and weather conditions.

Algal system of the Water2REturn demo site in Seville, Spain, has been successfully set off based on the development and upgrade of Algen’s ABG technology in the Algae Park in Slovenia (Algen & University of Ljubljana). The 400 m² pond was successfully inoculated with the algal culture from the Algae Park, already adapted to the liquid digestate. Currently, the produced algae are being processed by Kimitec and tested for their biostimulative action in the field tests.