PHYONA – phytomining of nanoparticles
Anthropogenic activities such as mining, industrial processes, transports and urban developments create a vast quantity of residual metals that concentrate in the soils surrounding the activities and persist in these soils for centuries creating a continuous hazard and limiting the sustainable use of land for food production and other uses.
This project proposes to create ad hoc plant systems able to collect (“mine”) the metals from the soils, transpose them to their aerial parts and consequently being collected through simple harvesting. The harvested biomass enriched with metal can then be treated (extraction) in a low energy process including recyclable solvents for the generation of clean lignin/cellulose and an enriched metal solution. The solution can be then used for the manufacturing of nano-metals (nano-synthesis) while recovering the solvents for re-use in the extracting step.
The project is focussed on the development and the optimisation of the three steps: mining; extracting and manufacturing.
In order to create the mining plant consortium, multi-selectivity, yield and capabilities of an assemblage of hyperaccumulators need to be studied. To do so, in situ and laboratory experiments are carried out. The experiments are based on the evaluation of the capacity of hyperaccumulators to work on a variety of soils and metal mixture and concentration. For this purpose soils with specific metal concentrations similar to existing mining environments have been devised, but also in situ sowing in gardens through voluntary participation in the projects is used. For this second method of approach to metal collections, the participants send the soils that undergo analysis in our laboratory hence generating a map of metals distribution in the UK with the parallel creating of pollution sources (such as links to transport hubs or industrial facilities), this method would then develop an innovative aim of working on urban contamination and potential urban mining.
The extraction step is being studied in a laboratory with the view of using the least hazardous solvents, the smallest volume and concentration. Two different approaches are under study to produce a fast collective extraction with the aim of separating the metals at a later stage. This steps also contains the development of an in situ solution for the performance of this process directly at the contaminated site.
Finally, the nano-synthesis stage is developed to maximise the use of the “mining” biomass and achieve an optimised green route to manufacturing. This fully enters in a circular procedure that makes use of the biomass for both the mining and the manufacturing finally resulting in the production of nanometals, clean solvents that can be re-used in the extraction step and clean lignin/cellulose.