Transformar os resíduos em recursos: Desenvolvimento de fertilizantes verdes através da recuperação de nutrientes de subprodutos agro-alimentares e efluentes pecuários

The NUTREC4AGRI project aims to devise a new, sustainable, and fully integrated solution to the valorization of agri-food byproducts and livestock effluents as green fertilizers. The solution is based on a combination of the electrodialytic (ED) process and gas permeable membranes (GPM) to extract nutrients and organic compounds with biostimulant effects from wastes and their conversion into slow-release fertilizers such as struvite, vivianite, hydrogels and geopolymers. Pursuing a Zero Waste approach, electrooxidation (EO) will be combined with valorization processes to treat the residual waste left after nutrients and organic compounds extraction. The recovered fertilizers will pose an alternative to synthetic fertilizers produced from mined phosphates or highly-energy consumption ammonia production. The specific objectives are: - Screen different agri-food byproducts and livestock effluents rich in P, N and organic compounds and select those most amenable to electrodialytic process and gas permeable membrane technology; - Develop a novel prototype combining ED, EO and GPM technologies for nutrients and organic compounds valorization and treatment from agri-food byproducts and livestock effluents; - Optimize the conditions that lead to higher extraction of nutrients and organic compounds and minimize energy consumption, ensuring thus a more efficient and economically attractive prototype to the sector, with low capital and operation costs; - Produce various green fertilizers (vivianite, struvite, hydrogels and geopolymers) using nutrients and organic compounds extracted from agri-food byproducts and livestock effluents; - Assess the agronomical value of the new green fertilizers and compare with the commercially available fertilizers; - Assess the in vitro multiplication effects with the recovered nutrient solutions for plant micropropagation; - Compare the proposed solutions against the current practices of fertilizers production, both economically as well in terms of environmental benefits. The ultimate goal of this research project is to substantially accelerate the advance of nutrient recycling processes to produce fertilizers. In this way, the proposed work intends to contribute to a greener, resource efficient and sustainable economy, in line with the European Community goals of using waste as a resource (Waste Framework Directive and the European growth strategy Europe 2020) and European Community concepts of a circular economy, with positive impacts on food security and on the economic sustainability of agriculture.