The removal and recovery of heavy metals from wastewater by innovative and environmental friendly nanomaterials is investigated and optimized. To favour the development of the circular economy, the research overarching goal consists in the recovery of these metal and metalloids and subsequent nanomaterials restoration. To this purpose, iron oxide nanoparticles (ION) and nano zero valent iron particles (nZVI), stabilized with natural biopolymers (chitosan, carboxymethyl-cellulose), will be synthetized and tested. Nanocomposites of the mixed iron oxides will be also produced and used, by green synthesis methods (natural extracts from agroindustrial wastes will be used as reducing agents rather than the classical toxic and hazardous NaBH4 and N2H4) and employing water as the solvent in the production process. The synthesis will be carried out in batch and in continuous mode, by means of a Spinning Disk Reactor (SDR), to ensure optimal nanomaterial physico-chemical characteristics and to grant an easier industrial process scale-up. The production process will be optimized with respect to the particle size distribution curve and nanoparticles stability.
Adsorption/desorption tests will be carried out first in batch mode at room temperature, and the main operating parameters will be investigated, in order to assess the optimum conditions for heavy metals removal.
The same tests will be performed in continuous mode, optimizing the process parameter according to the values obtained from batch studies. Nanoparticles recovery will be carried out by magnetic separation. A pH adjustment will grant heavy metal recovery and the nanomaterials restoration.
Process mechanisms and kinetics will be studied. In addition, a comprehensive model of the whole process will be designed and optimized.
Aiming at reusing the reclaimed water to irrigate plants in agriculture preliminary experiments will be conducted on Vitis vinifera, Hypericum perforatum and Quercus ilex plants grown in pots.
