•The elements composition of bottom and fly ashes from 2 Italian MSWI is investigated.•We conduct a substance flow analysis for critical elements and other metals.•Many of critical elements are ...enriched in specific granulometric fractions.•An onsite procedure to improve the relative recovery efficiency is suggested.•Waste from MSWI might represent a low-concentration stream of valuable elements.
The incineration of municipal solid wastes is an important part of the waste management system along with recycling and waste disposal, and the solid residues produced after the thermal process have received attention for environmental concerns and the recovery of valuable metals. This study focuses on the Critical Raw Materials (CRM) content in solid residues from two Italian municipal waste incinerator (MSWI) plants. We sampled untreated bottom ash and fly ash residues, i.e. the two main outputs of common grate-furnace incinerators, and determined their total elemental composition with sensitive analytical techniques such as XRF and ICP-MS. After the removal of a few coarse metallic objects from bottom ashes, the corresponding ICP solutions were obtained using strong digestion methods, to ensure the dissolution of the most refractory components that could host significant amounts of precious metals and CRM. The integration of accurate chemical data with a substance flow analysis, which takes into account the mass balance and uncertainties assessment, indicates that bottom and fly ashes can be considered as a low concentration stream of precious and high-tech metals. The magnesium, copper, antimony and zinc contents are close to the corresponding values of a low-grade ore. The distribution of the elements flow between bottom and fly ash, and within different grain size fractions of bottom ash, is appraised. Most elements are enriched in the bottom ash flow, especially in the fine grained fractions. However, the calculated transfer coefficients indicate that Sb and Zn strongly partition into the fly ashes. The comparison with available studies indicates that the CRM concentrations in the untreated solid residues are comparable with those residues that undergo post-treatment beneficiations, e.g. separation between ferrous and non-ferrous fractions. The suggested separate collection of “fresh” bottom ash, which could be processed for further mineral upgrading, can constitute an attractive option of the waste management system, when physical–mechanical devices are not available or could not be implemented in old MSWI systems. The suggested procedure may lead to the improvement of recovery efficiency up to 83% for CRM and 94% for other valuable metals.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Valle Mandriole is one of the two last remaining freshwater wetlands in the coastal area of Ravenna (NE Italy). In 2011, a management technique that involves the complete drainage of the southern ...portion of Valle Mandriole during summer has been undertaken. In the present study, the effects of this artificial drying on the benthic macroinvertebrate fauna were assessed using a beyond before-after-control-impact (beyond BACI) sampling design. Macroinvertebrates dwelling on macrophytes and in bare sediments were sampled in the impact location and in four control locations, two times before and two times after the drying period. Simultaneously, water samples were collected to monitor chemical properties potentially affecting the studied organisms. Biological and chemical data were analysed by multivariate statistical methods. The statistical analysis did not detect any significant effect of the management action on the benthic macroinvertebrates or on the water chemical and physical properties. This contrasts with some previous results, suggesting that the effects of a management strategy based on draining completely dry and then reflooding a wetland area are site specific. However, it is necessary to consider that the present study does have some limitations, in particular, the differences between impact and control locations and the timing of the sampling. The highest biodiversity was observed in one small and isolated control location; this highlights how maintaining, protecting, restoring and even creating small ponds may play an important role in biodiversity conservation.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The fan shell Pinna nobilis is the largest bivalve endemic to the Mediterranean and is actually a strongly endangered species. Due to the biological, ecological, and historical relevance of this ...species, the research of a non-lethal method to relate the element content in organism's tissues and environment can provide information potentially useful to evaluate environmental pollution and organism physiological status. In this study, a screening on element concentration in the animal growing environment (seawater and sediments) and in four soft tissues (hepatopancreas, gills, mantle, and muscle), and two acellular tissues (calcite shell layer, and byssus) was performed. The comparison among these results was used to assess whether the no-lethal acellular tissue element concentration can be used to reveal the element presence in the environment and soft tissues. Elements, such as B, Ag, As, Mn, Mo, Pb, or Se, showed a possible relationship between their presence in the byssus and soft tissues. In the byssus Cr, Sb, Sn, and V have shown to be mostly related to the environment, more than the soft tissues, and might be used to draw a historical record of the exposure of the organism. The element concentration in the calcite shell layer did not relate with environmental element concentrations. Essential elements, like Cu, Fe, Ni, and Zn, were present in calcite shell layer and byssus and are likely related to their biological activity in the organism. The research also gave an overview on the presence of pollution and on the preferential intake route of the element. In summary, this study, performed on a limited number of specimens of this protected species, indicated that element concentration in the byssus can be applied as non-lethal method to monitor this endangered species and its interaction with the elements in the growing environment.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Bauxite deposits are widespread in NW Sardinia. They formed during the middle Cretaceous, in consequence of a period of emergence of the Mesozoic carbonate shelf. In the Nurra area the geometries ...derived by the Middle Cretaceous tectonic phases controlled the ore typologies. Two bauxite profiles, laying on different bedrocks, were sampled. The bauxitization proceeded from the surface downward, with the accumulation of Al^sub 2^O^sub 3^ and residual 'immobile' elements (Al, Ti, HFSE), and corresponding mobility and loss of SiO^sub 2^ and Fe^sub 2^O^sub 3^. Epigenetic kaolinite formed close to faults and joints, probably as a result of silicification, introduced by low temperature hydrothermal solutions. Rare earth elements, especially LREE, are concentrated in Fe-rich bauxite horizons, probably due to scavenging by goethite. REE-enrichment is not observed in the boehmite-rich horizons. Very high REE contents are observed in a Fe-depleted horizon due to the occurrence of REE accessory minerals, probably of the bastnäsite group. Conservative indices, including TiO^sub 2^/Al^sub 2^O^sub 3^ and Ti/Cr ratios, and Eu anomalies (Eu/Eu*), suggest that the deposits formed by weathering of sediments derived from mafic rocks of the Hercynian basement. This, in turn, implies that the basement was exposed during middle Cretaceous.PUBLICATION ABSTRACT
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The contamination of agricultural soil with potentially toxic elements (PTEs) such as cadmium (Cd), lead (Pb), chromium (Cr), zinc (Zn), nickel (Ni), and copper (Cu) persists and intensifies in food ...crops posing a risk to human health. When used as effective soil manures, biomass conversion to organic amendments can help to deal with this deteriorating problem and, at the same time, remediate PTEs within contaminated soil. The present study compared the potential of orange peel-derived biochar (OPDBC) and poultry manure (PM) toward reducing the bioavailability of PTEs when they are applied to degraded agricultural soil (DAS). It further evaluated PTEs bioaccumulation in okra (
Abelmoschus esculentus
L.) and the associated health risks. The DAS was amended with OPDBC and PM at 1%, 3%, and 5% application rates, and okra was grown in these modified soils in pots (2.5 kg soils each). Compared to control (contaminated soil), OPDBC treatments significantly reduced Cd availability, reduced Cd uptake to plants (21–37%), followed by Ni (18–27%), and increased okra plant biomass (15–39%) and fruits weight (40–93%). PM effectiveness was lower than OPDBC and reduced Cd uptake (8–33%) and increased vegetative biomass and fruit yield (3–22% and 13–33%, respectively). OPDBC 5% demonstrated the best results in terms of immobilization and reduction of Cd uptake by plants (37%) and fruits (41%). The contamination factor and pollution load index (PLI) of PTEs showed low pollution level (PLI < 1) in terms of PTEs except Cd, in OPDBC treatments, as compared to PM and control. When compared to other PTEs, the Cd bioavailability in okra fruits decreased with 5% application rate of OPDBC. In the current study, OPDBC5 decreased the daily intake and health risk index (HRI˂1) of Cd and other selected PTEs. The total hazard index (THI) values of selected PTEs were relatively lower for the adults than the children, thereby reduced by OPDBC and PM applications, while OPDBC5 reduced the incremental lifetime cancer risk (ILTCR) of Cd from (25–41%) via okra fruits consumption for both the adults and children when compared with 1%, 3%, and control treatments. The study results show that among amendments, orange peel waste conversion to biochar as OPDBC amendment and its addition to DAS should be a viable alternate method that could mitigate the health risk by remediating and immobilizing the PTEs like Cd and minimize its subsequent accumulation in vegetables.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Introduction:
Municipal Solid Waste Incineration (MSWI) plants generate significant amounts of solid end-products, such as bottom ash (BA), containing potentially toxic elements like Cr, Ni, As, Cd, ...and Pb, base elements (e.g., Si, Al, Fe, Ti, Cu, and Zn), and other technology-critical elements (TCE), such as Co, Ga, Mg, Nb, P, Sb, Sc, V, Li, Sr, and REE. The accurate determination of these elements in anthropogenic wastes and the assessment of their removal are crucial for the circular economy.
Methods:
This paper aims to characterize BA samples from two Italian MSWI plants (named FE and FC) by X-ray fluorescence (XRF) and comparatively assess the removal of a selection of elements using the aqua regia digestion (ARD) method, followed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analytical determination.
Results and discussion:
According to the XRF analysis, Ca, Fe, Al, Mg, and Na had high concentrations in BA, and their contents increased with decreasing particle size in both FE and FC samples. The Enrichment Factor (EF) based on the upper continental crust’s average values of Zn, Cu, and Pb was high (EF > 30), while Cr, Ni, and As were scarcely enriched (EF > 1), and REE enrichment was very low (EF < 1). In both FE and FC plants, the Degree of Elements Extractability (DE) was high (>80%), especially in the fine-grained fractions of MSWI bottom ash. The Enrichment Factor (EF) based on the upper continental crust average values of Zn, Cu, and Pb was high (EF > 30), while Cr, Ni, and As were scarcely enriched (EF > 1), and REE enrichment was very low (EF < 1). The bibliometric analysis helped highlight research trends in the assessment and treatment of MSWI-BA, discriminating the literature impact on environment/health issues and recovery/recycling strategies for the circular economy associated with the MSWI-BA material.
Conclusion:
Although higher data coverage is needed, the present study suggests ARD as an effective method for better understanding the environmental impact and recoverability of useful elements from anthropogenic materials like MSWI bottom ash.
Sediments represent a critical compartment of marine coastal ecosystems due to the toxic and long-lasting effects of the contaminants buried therein. Here, we investigated the properties of surficial ...sediments in front of the Southern Marche Region coast (Central Adriatic Sea, Italy). The grain size of the surficial sediments was determined by X-ray sedigraphy. TN and OC contents were determined by elemental analysis. The concentrations of Al, Fe, Mg, K, S, Ca, Ti, P, Na, Mn, Mg, Li, As, Ba, Ga, Pb, Sr, and Zn were determined by ICP-OES to evaluate their spatial patterns and temporal trends. A Q-mode Factor Analyses was applied and resulted in the identification of three compositional facies (Padanic, Coastal, and Residual) characterized by common biogeochemical, mineralogical, sedimentological properties, transport pathway, and source. Some pollution indicators, such as the enrichment factor, the geoaccumulation index, and the pollution load index were calculated to assess the deviation from the natural background levels. The results showed a pollution by As and Ba due to the human activities in the 20th century. Furthermore, a general decreasing of Al, Ti, P, Co, Cr, Cu, Ga, Ni, Pb, Sc, V, and Y concentrations from the background levels suggested a change in the sedimentation processes during the last decades.
Landscape evolution in active mountain chains can be dominated by gravitational slope movements. This is observed in a large portion of the Reno river catchment, Apennines, Italy, where weak rocks, ...such as clayshales, are subject to earthflows that control hillslope morphology and supply sediments to the channel network. In this paper, we evaluate the sediment flux generated by earthflows and compare it with Holocene-averaged deposition rates to assess the contribution of mass movements to landscape evolution. Present-day hillslope sediment flux is estimated by combining measured displacement rates (72 inclinometers) and spatial attributes of earthflows and historical frequency of reactivations. Averaged sediment yield (~1.6x103t/km2/yr) compares well with similar studies on earthflow-dominated landscapes, despite notable differences in methodology.
In the study area, the connectivity between hillslopes and the stream network is well developed and no significant sediment sinks influence the sediment transport processes. We document best estimates of regional sediment fluxes and related uncertainties, based on available data. Coarse limestone fragments, present in the clayshales, are used as a natural sediment tracer to allow a comparison with sedimentation rates taking place at the mouth of the intramontane catchment. Here, available borehole logs, 14C datings and stratigraphic correlations of the alluvial fan are used to obtain an estimate of the deposition that took place during Holocene times. Taking also into account the role of solute transport, sedimentation rates are compared to earthflow sediment production rates. Results show a good agreement and demonstrate that earthflows are the primary mass wasting process in these weak rock lithologies.
We document best estimates of regional sediment fluxes and related uncertainties. Present earthflow sediment production outpaces Holocene-averaged sedimentation rates by a factor of two. The gap between sediment production and deposition can be partly justified by uncertainties associated with our estimates and by time-scale differences. With this respect, the dynamic equilibrium between erosion and deposition, is likely affected by intra-Holocene oscillations at a short time scale (10 to 1ky) attributable to climate variability. Terraced deposits documenting sedimentary episodes would also support such interpretation.
► We document earthflow spatial attributes, geometry and displacement rates. ► We estimate earthflow sediment production rate on a regional basis. ► Earthflows are the primary erosion process in weak rock lithologies. ► Present hillslope sediment production equals or exceeds Holocene sedimentation rates.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
This study was conducted in the Middle Branch of Bue Marino Cave (Sardinia, Italy) to reconstruct paleoecological conditions during the Holocene through microfaunal proxies in seven surface sediment ...samples and a short sediment core (BMD-2018, 18 cm), all collected in 2018 and another core sampled in 2021 (BMD-2021, 28 cm). The first attempt at dating cave sediment through luminescence was conducted on BMD-2021; the derived age was 6.04 ± 0.47 ka at 18 cm depth. Although continuous sedimentation and constant rates are not probable in the cave, this indicates that the sedimentary record dates to the early times after the Holocene flooding of the cave by the sea. Benthic foraminifera and grain size were analyzed in all surface samples and core BMD-2018, while only benthic foraminifera were studied in BMD-2021. The recent foraminiferal assemblages, studied from an ecological point of view, were applied as modern analog to reconstruct the paleoecological conditions in sediment cores. Significant changes in the sedimentary environment were excluded; the two cores showed a similar foraminiferal turnover at a similar depth, from an older assemblage with prevailing indifferent Ammonia inflata to a younger one with prevailing opportunist Eggerelloides advena. This turnover was attributed to changes in the amount and/or quality of available nutrients. Based on these results, this event is likely related to possibly attributable to the effects of climate changes that occurred in the Holocene. However, more extensive studies are necessary to better understand the effects of the climatic/environmental events in the Late-Holocene in the caves. Although it represents a first attempt at paleoenvironmental reconstruction based on sediments from a Mediterranean marine cave, this study demonstrated that benthic foraminifera are refined paleoenvironmental proxies and that the integrated approach with the luminescence dating produces reliable results for studying the effects of global changes in these environments.
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
Abandoned mining wastes are both an environmental challenge and a possible secondary raw material source. The characterization and monitoring of these sites are often expensive and cumbersome because ...of the need of repeated field surveys. Remote sensing data are a cost-effective alternative that helps in producing multiscale maps of mining wastes. These maps can be used to investigate and monitor the spatial patterns of different elements within the mining wastes. In this work, Sentinel-2 images are combined with the geochemical samples in order to map the distribution of iron, copper, chromium, and cobalt. The target area was the Vigonzano mining wastes in Northern Apennines (Italy) where there are a small number of geochemical analyses but a large amount of satellite image data. We used the multivariate geostatistical estimation method (Co-Kriging) that exploit the meaningful spatial correlation between the elements of interest and band ratios (obtained from Sentinel-2 images). The concentration maps highlighted subareas for Cu and Cr with an estimated grade of about 0.3% and 0.2%, respectively. In addition, the critical element Co showed an enrichment in the south-east part of the mining wastes, in a similar pattern as Cr. Instead, the obtained maps show Ce, La, Rb, and Nb depletion compared to the surrounding agricultural areas. The concentration maps were intended as a prefeasibility study to determine enriched areas for further detailed investigation.
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