ENVIRONMENTAL ASSESSMENT OF UNDERCURRENT AGRICULTURAL TECHNOLOGIES TOWARDS CIRCULAR NUTRIENT MANAGEMENT

Circular Economy consists of re-designing effective processes that allow the subsequent recovery of wastes for new production methods, avoiding using new resources. However, an emerging holistic approach requires evidence of its systemic capacities to transition from unsustainable linear practices that had led our planet to face significant environmental problems such as climate change and alteration of biochemical flows. This study aimed to assess technologies that have proven to close C, N, and P loops regarding their overall environmental impact from two study cases; a) Microalgae production by using nutrient and water recovered streams; and b) Integrated anaerobic digestion system with precision agriculture, and bioenergy production. Results showed that the re-use of end-products is critical for positive environmental impacts due to avoided emissions from production, transport, and use of mineral sources, satisfying the aim of supporting a closed-loop integrated system. Nutrient recovery practices reduced GHG emissions, protected and enhanced soil carbon stocks, improved ground- and surface-water quality.