Treasure from trash: mining critical elements from sewage sludge using plants

The global consumption of metals and metalloids is increasing rapidly owing to an ever-growing demand from technology and renewable energy industries.

These include selenium (Se), cobalt (Co), and nickel (Ni) for which the 2050 projected consumption is expected to be 5 to 10-folds higher than today.

These elements are defined as “critical” since their supply is expected to be critically limiting in the near future.

Considering the increasing demand for critical metal(loid)s, the use of sewage sludge (SS) as alternative resource of these raw materials can constitute an appealing alternative to make “treasure out of trash”, thereby promoting the circular economy.

MinE-UP aims at contributing to the supply of Se, Co, and Ni exploiting metal(loid) enriched SS through targeted phytomining. The envisaged solution will utilize degraded mined land as locations in which SS phytomining can safely take place.

MinE-Up is expected to: 1) Reduce of the overall amount of disposed SS and the connected environmental and economic costs; 2) Generate a positive environmental impact by enhancing ecosystem restoration in mined areas; 3) Contribute to the valorization of mined lands, creating new opportunities for local communities. 4) Characterize the new plant-based products (Se, Co, Ni bio-ores) and evaluate their possible applications.

MinE-UP outcomes will have relevant impacts at scientific, economic, and societal levels.

They will range from the investigation of metal accumulation physiology in plants growing on SS, to the assessment of the process effects on land remediation.

From the agronomical aspects of hyperaccumulator cultivation, to the procedures of extraction and purification of the valuable elements and molecules contained in hyperaccumulator biomasses.

In the long period, MinE-UP innovative methodologies could help in modernizing and re-invent SS disposal methods, giving a second life to this waste while possibly directing the updating of national and EU regulations.