A paradigm shift towards a new industrial policy aimed at sustainability and innovation is underway in Europe. Circular Economy (CE) is a model to rethinks the systems of production and consumption to create a waste-free future. This transition requires a cultural and structural change that can be obtained by aligning the educational programs in order to train people needed to build a sustainable development in Europe.
In the present work, we present a learning pathway, designed for High schools, useful to introduce some basic concepts of CE among youngsters by starting from a laboratory experience which is part of the European project Raw Matters Ambassadors at Schools, an innovative program to make science education attractive for youngsters [1]. RM@Schools promotes a wide dissemination action on RM-related themes in Schools and Society through strategic European partnerships among Research, School, and Industry. In this context, the students of a high school class of Bologna (IT) were involved in lab experiments to approach the topic of raw materials (RMs) considered critical by EU and the necessity of their recovery. Phosphate rock (P) is one of the critical RM for EU, and it is primarily used in agriculture [2-3]. It is expected after 2033 a huge decline in P extraction and consequently, a dramatic decrease in fertilizers, food and feed [4].
The goal of the lab experience was to educate students that P can be recovered from secondary resources such as urine, a component of wastewater. The laboratory activities were planned in a theoretical training under the guidance of the teacher and another practice where students become the main protagonists of all phases of the work (from design to evaluation). The laboratory activity involved three experiments with various levels of difficult: i) production of synthetic urine from which struvite is extracted; ii) to build a simple reactor to recovery struvite; iii) to test the fertilizer property of struvite on basil plants in hydroponics.
By using the material created for this learning path, students become familiar with the concept of biogeochemical cycles and specifically nitrogen and phosphorous cycling and learn that in CE end-of-life products must be considered as resources for another cycle. In addition, interactions between materials must be considered in order to define the best circular solution. Awareness of the benefits of closing material loops can be raised among students in a simple and engaging way.
Keywords: Struvite, hydroponics, P recycling, circular economy, raw materials, school.