Algal technologies for green products – ALGreen

Growing urbanization, increasing resource consumption, climate change, and the transition to a low carbon society require increasing flexibility of the urban and rural environment and more sustainable wastewater management addressing reuse of valuable resources such as water, nutrients, biomass, and energy. In this aspect, waste should not be wasted and wastewater treatment plants can shift to “closing material and energy streams” by implementing technology to reuse water, biomass, and energy and transforming them from waste to valuable green products. Nature-based solutions can be applied for soil health, carbon mitigation, downstream water quality protection, biodiversity benefits as well as assisting agricultural production and supply chains to achieve net-zero environmental emissions while achieving food and water security and meeting climate goals. Further on, Nature-based solutions have been identified as a key adaptation of Climate Action (Green deal), UN SDGs, and EU’s Circular Economy Action Plan to address the environmental, climate and agricultural challenges. Algal technologies as one of several Nature-based solutions are experiencing interesting advancements in the field of wastewater treatment and recovery efficiency of resources for agricultural use. This calls for the development and scientific evaluation of the potential of algal technologies for the production of green products (e.g., reclaimed water, algal biomass, organic fertilisers, green mulch, biostimulants) while minimizing potential environmental and health risks. The core principle of the proposed project is the research of a closed-streams concept based on algal technologies, in lab-scale photobioreactors and a pilot-scale high-rate algal pond (HRAP), to produce green products of two components (1-water, 2-biomass). In the project, HRAP will be optimized to increase biomass production and efficient harvesting during the wastewater treatment process. Next, different green products from algal biomass will be developed and tested including direct fertigation, organic fertilizers, and green mulch as soil amendments. Additionally, treated water will be used for irrigation. This approach will allow the acquisition of new scientific knowledge of green products produced by algal technologies, based on lab-, pilot-scale experiments, and tested by lysimeter field and pot experiments for safe reuse in agriculture. New understanding, based on monitoring of soil and plants, will be gained on how potentially hazardous compounds (heavy metal, pathogens, microplastics, contaminants of emerging concern, and multi-drug resistant bacteria) and nutrients from municipal wastewater can cycle and how environmental and health risk can be managed by water and nutrient reuse. Green products such as water for irrigation, organic fertilisers, green mulch, and biostimulants will be evaluated, based on existing legislation, and compared to products of conventional wastewater treatment technologies. Additional legislative limits will be suggested. Finally, the proposed research, based on closed-streams with algal technology, will go beyond state-of-the-art by addressing parallel benefits and treats by implementing integrated water resource management by the usage of Nature-based solutions (Green deal) and Circular economy principles.