In this work, mycorrhizal-assisted phytoextraction (MAP, Helianthus annuus–arbuscular mycorrhizal fungus Rhizophagus intraradices–Zn-volcanic ashes) was applied for the recovery of secondary and critical raw materials (SRMs and CRMs, respectively) from Joda West (Odisha, India) mine residues, within a novel multidisciplinary management strategy. Mine residues were preliminarily characterized by using advanced analytical techniques, and subsequently mapped, classified and selected using multispectral satellite Sentinel-2A images and cluster analysis. Selected mine residues were treated by MAP at laboratory scale, and the fate of several SRMs (e.g., Zn, Cr, As, Ni, Cu, Ca, Al, K, S, Rb, Fe, Mn) and CRMs (such as Ga, Ti, P, Ba and Sr) was investigated. Bioconcentration factors in shoots (BC_S) and roots (BC_R) and translocation factors (TF) were: 5.34(P) > BCS > 0.00(Al); 15.0(S) > BCR > 0.038(Ba); 9.28(Rb) > TF > 0.02(Ti). Results were used to predict MAP performance at larger scale, simulating a Vegetable Depuration Module (VDM) containing mine residues (1 m³). Estimated bio-extracting potential (BP) was in the range 2417 g/m³ (K) > BP> 0.14 g/m³ (As), suggesting the eventual subsequent recovery of SRMs and CRMs by hydrometallurgical techniques, with final purification by selective electrodeposition, as a viable and cost-effective option. The results are promising for MAP application at larger scale, within a circular economy-based approach.

Raw materials are essential for all sectors of the economy as well as for all innovative technologies. Currently, industry is largely dependent on imports and consumption of these materials, and in the future, following the global energy transition, this trend will drastically increase. For this reason, it is necessary to develop new strategies to meet the supply–demand of raw materials by strategic sectors and technologies. To this end, mining residues are turning into viable raw materials sources as they represent reliable access to valuable resource supply. This work aims to validate a methodology providing more in-depth quali-quantitative information about 100 samples of mining residues collected in the Joda West mine (India) by multidisciplinary strategy in order to valorize and promote efficient resource use. In this paper, physicochemical and mineralogical characterization and hyperspectral signatures have been integrated with satellite Sentinel-2A data. In particular, the X-ray powder diffraction (XRPD), X-ray fluorescence (XRF), and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) analyses indicated the presence of mining residues samples rich in raw materials that were possible to spectrally distinguish in order to use them as input for the object-oriented classification of a satellite image. The satellite resulting map highlighted four different classes of mining residues with mean concentrations of around 36% for hematite, 23.5% for quartz, 9% for kaolinite and 5% for pyrolusite. These results represent the possibility of transforming an environmental problem (mining residues) into a resource potentially exploitable by industries knowing their composition and position in the study area. Moreover, by doing so, it will be possible to ensure sustainable consumption of the raw materials and to build resilient economies and societies, minimizing environmental degradation.

In recent times, the development of innovative processes permits the application of a circular economy approach to the management and exploitation of mining waste with respect to human health and environment, such that society is changing its fundamentally negative perception of the mining sector. This study presents the opportunities and challenges of supplying raw materials from waste using a remote sensing technique, mycorrhizal-assisted phytoremediation, and hydrometallurgical techniques to transform mining waste from a problem to a resource. Soil/mine wastes from the Sierra Pintada mine (Mendoza, Argentina) were mineralogically and chemically analyzed, and then, a mapping of the mining waste was carried out by Sentinel-2A images to identify areas with similar characteristics. The bioaccumulation of HMs by autochthonous shrubs was also determined to select accumulator plant species, and to evaluate their potential for phytoremediation of mine soils at different technological scales, when they were inoculated with arbuscular mycorrhizal fungi originated from a mining-impacted area. RMs were recovered from plant biomass by scaling in bioreactors, the depuration module, and hydrometallurgical techniques. The encouraging results highlight that this multidisciplinary approach can be applied to meet the increasing demand for RMs supply and, at the same time, to protect the environment and public health.

The worldwide mining industry produces millions of tons of rock wastes, raising a considerable burden for managing both economic and environmental issues. The possible reuse of Fe/Mn-rich materials for arsenic removal in water filtration units, along with rock properties, was evaluated. By characterizing and testing 47 samples collected from the Joda West Iron and Manganese Mine in India, we found As removal up to 50.1% at 1 mg/L initial As concentration, with a corresponding adsorption capacity of 0.01–0.46 mgAs/g mining waste. The As removal potential was strictly related to spectral, mineralogical, and elemental composition of rock wastes. Unlike rock crystallinity due to quartz and muscovite, the presence of hematite, goethite, and kaolinite, in association with the amorphous fractions of Fe and Al, enhanced the As adsorption. The natural content of arsenic indicated itself the presence of active sorptive sites. The co-occurrence of site-specific competitors (i.e., phosphate) represented a consequent limitation, whereas the content of Ce, Cu, La, and Pb contributed positively to the As adsorption. Finally, we proposed a simplified multiple linear model as predictive tool to select promising rock wastes suitable for As removal by water filtration in similar mining environments: As predicted = 0.241 + 0.00929[As] + 0.000424[La] + 0.000139[Pb] − 0.00022[P].

The Central Cryptoporticus on Rome’s Palatine Hill is a key underground monument of the Imperial period whose accessibility and long-term conservation are increasingly constrained by localised deformation, differential settlement, and cavity-related instability. Because these hazards are strongly conditioned by the nature and evolution of the foundation interface, we investigated how stratigraphy, mineralogy, and microstructure interact to control present-day vulnerability. Lithofacies logging from three boreholes (S1, S2, 1MS) and a trench site was integrated with portable X-ray fluorescence (pXRF), X-ray diffraction (XRD), petrography, and soil micromorphology on representative foundation units: pedogenised floodplain deposits of the Aurelia formation (AEL), variably altered and cemented volcaniclastic deposits of the Villa Senni formation (VSN), and underlying fluvial sand-silt deposits of the Fosso del Torrino formation (FTR). Results show that AEL is best interpreted as a structured, compound palaeosol shaped by polyphase wetting-drying and pedogenic redistribution. Alluvial clay coatings, vertic fabrics/slickensides, Fe-Mn redox features, and carbonate nodules produce a centimetrescale mosaic of contrasting porosity and hydraulic behaviour, implying strong sensitivity to moisture change and water routing. In VSN, two end-member petrofacies coexist: a friable, pedogenised ash-rich facies where vitric-derived material is extensively transformed into clays and secondary phases, and a more coherent lithoid facies strengthened by zeolite and calcite cementation. Although cementation increases cohesion locally, hydrous secondary phases and alteration pathways create moisture-sensitive fabrics that can promote microcracking and softening where saturation persists. Across the foundation profile, rainwater infiltration, percolation, and capillary rise couple AEL and VSN, driving shrink-swell deformation, alteration and cement redistribution, and spatially patchy CaCO₃ re-precipitation that is insufficient to offset ongoing weakening. Where these moisture-sensitive horizons intersect a dense network of anthropogenic voids, the likelihood of deformation and local collapse increases, making differential settlement and cavity-roof instability the dominant hazards for the monument. The findings support conservation priorities focused on surface- and groundwater control, targeted stabilisation of the most compressible or voided foundation sectors, and long-term hydro-geotechnical monitoring.