1,720,989 research outputs found
Mt. Giovo thrust system: 2D reconstruction and shortening computation and 3D geogical model. 2D and 3D Computer Models and Report.
No full textModello cinematico in 2D e geologico in 3D su piattaforma Move 2008, relazione annuale 2009 per lo sponsor, Ditta Midland Valley Exploration Ltd.
Geochemical and magnetic data on anthropogenic ashes from municipal solid waste incineration (MSWI)
Full text linkThis paper reports supplementary information to “Understanding room-temperature magnetic properties of anthropogenic ashes from municipal solid waste incineration to assess potential impacts and resources” [1]. The sample-set is composed of 47 samples of bottom (BA) and fly (FA) ashes from Municipal Solid Waste Incineration (MSWI), including eight magnetic extracts of selected BA and FA materials. The sampling relies on a simple random sampling strategy at four different MSWI sites in Northern Italy [2]. X-Ray Fluorescence (XRF) analysis on pressed powder pellets, microscopic observations on thin sections and stubs, and magnetic analysis were carried out. Various magnetic measurements are presented: the magnetic susceptibility measured at two different frequencies (0.47 and 4.7 kHz); the mass-specific susceptibility of ARM (χARM), expressed in m3/kg, calculated after mass-normalization and bias DC field correction; experiments for isothermal remanent magnetization (IRM) experimented were also conducted. The latter measurement allowed the calculation of additional parameters, such as the coercivity of remanence (B0cr) and the S-ratio [3]. The IRM acquired in a field of 1.0 T was regarded as the saturation IRM (SIRM). Mass-specific magnetic susceptibility (χ) was calculated by dividing the volume susceptibility by the sample mass. Finally, hysteresis loops and backfield curves at room temperature were measured on selected samples and are available. Data can be reused as groundwork information in future studies on MSWI residues. It would be essential to produce new data on geochemical and magnetic characteristics of MSWI residues to assure good coverage of data for enhanced sustainability of these heterogeneous streams of anthropogenic materials. This combination of methods will contribute to paving the way for quick and reliable resource assessment as well as to promote environmental sustainability
Understanding room-temperature magnetic properties of anthropogenic ashes from municipal solid waste incineration to assess potential impacts and resources
No full textUnderstanding room-temperature magnetic properties of anthropogenic ashes from municipal solid waste incineration to assess potential impacts and resources
No full textEnvironmental magnetic studies are widely used to trace sources of anthropogenic pollution and have revealed promising applications to the urban waste management system. Here, a collection of solid samples from Municipal Solid Waste Incinerators (MSWI) were studied to probe the capability of geochemical and magnetic data integration as a tool for assessing mineralogy, grain-size, and metal enrichment. A data set of room-temperature magnetic parameters was compared with chemical data by X-ray fluorescence and electron microscopy observations. The aim was to validate or reject methods for urban mining purposes, testing and exploiting the correlations that magnetic properties typically experience with iron and heavy metals, as well as their relation to magnetic grain-sizes (from mm-scale down below 30 nm). We noted that the room-temperature magnetic data of MSWI ashes, used to assess grain-size according to the magnetic domain states, is complicated by the clumping of tiny and large grains displaying similar magnetic properties, so it needs to be supported by optical methods or more advanced magnetic techniques. On the other hand, the integration between magnetic and geochemical data, constrained by the analyses of the magnetic/diamagnetic extracts, helped in assessing magnetic mineral assemblages and potential metal enrichment
Impact and recoverability of metals from waste: a case study on bottom ash from municipal solid waste incineration plants
No full textIntroduction: 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
Particle size and potential toxic element speciation in municipal solid waste incineration (Mswi) bottom ash
Full text linkThe speciation of potentially toxic elements (PTE) in bottom ashes from municipal solid waste incineration (MSWI) and their relationship with grain size is investigated. The proposed enrichment of several potential toxic elements in lower sized grains is discussed, comparing the literature and new data on Parma’s waste incinerator. Results from X-ray fluorescence spectrometry (XRF), SEM-EDS, and XRD analyses on different grain size show (1) a positive Si-trend, correlated with grain size and few lithophile elements, such as Zr and Rb. In Parma, Al, K, Mg, and Fe also correlate with Si for the portion below 2 mm; (2) a Ca-trend, with a strong negative correlation with Si and a positive correlation with loss on ignition (LOI), S, Cl, Ti, Zn, Pb, and Sn. Mineralogical composition shows a little change in grain size, as in previous investigations, but with substantial differences in amorphous content. SEM-EDS analysis shows that the amorphous portion is highly heterogeneous, with portions coming from melting during incineration, residual glass, and unburnt loss on ignition (LOI). The above results show that PTE elements are either present as metals (such as Cu and Ni, or Zn, Pb and Sn) in carbonate, sulfate, and amorphous residual LOI portions
Geochemical characterization of surface sediments from the Ridracoli reservoir area and surroundings, Italy. Details on bulk composition and grain size
No full textSediment characterization of Ridracoli reservoir, an artificial lake for water supply, and surroundings of the Fiumi Uniti catchment in the northern Apennines, Emilia-Romagna, Italy, is carried out to evaluate the overall status of the drainage basin encompassing the reservoir. The study area combines the reservoir catchment that is part of the Foreste Casentinesi-Monte Falterona-Campigna National Park, formed by the construction of a dam operating since 1982 for drinking water storage and electricity production, and the upstream side of Fiumi Uniti catchment that flows into the Adriatic Sea, including also nearby sub-catchments of Ridracoli reservoir, named Corniolo and Pietrapazza. We collected surface sediments within the area of the reservoir and riverbed sediments of surroundings catchments, analyzed grain size distribution and the chemical composition, including carbon and nitrogen. This work investigates the chemistry and distribution of elements within the study area, evaluates the dam's effect upstream and downstream, and studies the processes that happen in rivers and the reservoir. The bulk composition is mainly represented by SiO2, Al2O3, CaO, with high Corg content reflecting the Marnoso Arenacea Formation geology of the area. Statistical data analysis on the available parameters suggests the presence of two main types of sediment, namely clayey and carbonate-dominated sediments. On the reservoir area, the relationship between elements and clay matrix and organic matter, besides iron, points to a potential grain size influence, degradation of organic matter, and mineralization processes. The grain size analysis shows that silty and clayey sediments are in the bottom of the reservoir, and sand, is apparent in sediment samples from the tributaries, due to sorting effects and likely directly explained by metals concentrations. This reasoned investigation included further samples from the literature to consider the entire surrounding area and was supported by Principal Component Analysis and Cluster Analysis
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Urban mining of municipal solid waste incineration (MSWI) residues with emphasis on bioleaching technologies: a critical review
Full text linkMetals are essential in our daily lives and have a finite supply, being simultaneously contaminants of concern. The current carbon emissions and environmental impact of mining are untenable. We need to reclaim metals sustainably from secondary resources, like waste. Biotechnology can be applied in metal recovery from waste streams like fly ashes and bottom ashes of municipal solid waste incineration (MSWI). They represent substantial substance flows, with roughly 46 million tons of MSWI ashes produced annually globally, equivalent in elemental richness to low-grade ores for metal recovery. Next-generation methods for resource recovery, as in particular bioleaching, give the opportunity to recover critical materials and metals, appropriately purified for noble applications, in waste treatment chains inspired by circular economy thinking. In this critical review, we can identify three main lines of discussion: (1) MSWI material characterization and related environmental issues; (2) currently available processes for recycling and metal recovery; and (3) microbially assisted processes for potential recycling and metal recovery. Research trends are chiefly oriented to the potential exploitation of bioprocesses in the industry. Biotechnology for resource recovery shows increasing effectiveness especially downstream the production chains, i.e., in the waste management sector. Therefore, this critical discussion will help assessing the industrial potential of biotechnology for urban mining of municipal, post-combustion waste
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