|A new methodology for the restoration/valorisation of abandoned mines sites, within the Iberian Pyrite Belt, in the SE of Portugal, is addressed. Considering the great environmental concern of the case study and always bearing in mind metals availability, the project focus on three main pillars: soil, biochar and plants. Combined action of phytoremediation processes with biochar abilities to change metals species is expected to increase the restoration rate under sustainable economic and ecological conditions due to plant and biochar ability to detoxify free metals.
Selected biochars will be added to soil samples, in the absence and presence of selected native vegetation and should be able to balance carbon and nutrient soil deficiency while providing room for water storage, microbial bioaugmentation and metal adsorption or speciation modification. The soil/biochar/plants consortium will be inter-related and will provide new insights into phytoremediation strategies. Moreover, and to forecast plants ability to tolerate metals, photosynthesis pattern will be related with the antioxidant enzyme and detoxification pathways. Vegetation species selection will take also into account the need for low metal translocation and high productivity features enabling further valorisation as lignin-cellulosic feedstock for renewable energy production. Plant rhizosphere long-term phytomining potential is also desirable in a circular economy approach.