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This work is focused on the hydrothermal system developed in the Ischia volcanic field before Mt. Epomeo resurgence, and is based on the investigation of hydrothermally altered lithic clasts present in the volcanic deposits of Secca d’Ischia and Epomeo Green Tuff eruptions. We demonstrate that a wide high temperature hydrothermal system occurred in the Ischia volcanic complex, both in intracalderic and extracalderic areas, at the time of the caldera-forming paroxysmal phase (60-56 ka). This hydrothermal system was characterized by high temperatures ranging from 240 °C and 340 °C and fluids of marine (~3.5 wt% NaClequiv.) and meteoric origin (0.5 wt% NaClequiv.). In the intracalderic area, the hydrothermal system was exhumed during the resurgence of Mt. Epomeo; in the extracalderic area of the island the hydrothermal system was at least partially disrupted during the Secca d’Ischia eruption., Periodico di Mineralogia, Vol. 91 No. 3 (2022)

The depletion of fossil resources is driving the research towards alternative renewable ones. Under this perspective, 5-hydroxymethylfurfural (HMF) represents a key molecule deriving from biomass characterized by remarkable potential as platform chemical. In this work, for the first time, the hydrogenation of HMF in ethanol was selectively addressed towards 2,5-bis(hydroxymethyl)furan (BHMF) or 2,5-bis(hydroxymethyl)tetrahydrofuran (BHMTHF) by properly tuning the reaction conditions in the presence of the same commercial catalyst (Ru/C), reaching the highest yields of 80 and 93 mol%, respectively. These diols represent not only interesting monomers but strategic precursors for two scarcely investigated ethoxylated biofuels, 2,5-bis(ethoxymethyl)furan (BEMF) and 2,5-bis(ethoxymethyl)tetrahydrofuran (BEMTHF). Therefore, the etherification with ethanol of pure BHMF and BHMTHF and of crude BHMF, as obtained from hydrogenation step, substrates scarcely investigated in the literature, was performed with several commercial heterogeneous acid catalysts. Among them, the zeolite HZSM-5 (Si/Al=25) was the most promising system, achieving the highest BEMF yield of 74 mol%. In particular, for the first time, the synthesis of the fully hydrogenated diether BEMTHF was thoroughly studied, and a novel cascade process for the tailored conversion of HMF to the diethyl ethers BEMF and BEMTHF was proposed.

The pegmatite district of El Quemado (NW Pampean Ranges, NW Argentina) hosts several Ordovician pegmatite bodies of theLCT (Li, Cs, Ta) type. We present paragenetic assemblages for a set of samples from two of the El Quemado pegmatite groups,Santa Elena and Tres Tetas, and mineral chemistry analyses for gahnite, columbite-group minerals, tourmaline, micas, albite,microcline, and discuss the relation between their major element composition and the degree of evolution of pegmatite melts. Thechemical composition of rare element minerals allows recognizing an evolutive trend reaching highly differentiated compositions, with complex paragenetic assemblages including Li-, Zr-, U-, Zn-, P-, Mn- and Ta-bearing minerals. The temperature ofcrystallization during the magmatic phase was below 400 °C. Non-pervasive hydrothermal alteration, testified by a moderatepresence of phyllosilicates, affected the pegmatite bodies. Chlorite geothermometry indicates that the circulation of postmagmatic hydrothermal fluids occurred at a temperature ranging between 200 °C and 250 °C. The mineralogical featuresrecognized in the El Quemado pegmatite rocks have implications for the metallogenesis of the region, suggesting that thepegmatites potentially contributed to the genesis of Ta-Nb oxide placer mineralizations. Fil: López, Vanina Lucrecia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto Superior de Correlación Geológica. Grupo Vinculado al INSUGEO- Centro de Estudios Geológicos Andinos; Argentina Fil: Fulignati, Paolo. Universita Degli Studi Di Pisa. Dipartimento Di Scienze Della Terra; Italia Fil: Gioncada, Anna. Universita Degli Studi Di Pisa. Dipartimento Di Scienze Della Terra; Italia Fil: Azarevich, Miguel Basilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto Superior de Correlación Geológica. Grupo Vinculado al INSUGEO- Centro de Estudios Geologicos Andinos; Argentina

This work investigated the catalytic high-pressure CO

Pollution associated to marine plastic litter is raising increasing concerns due to its potential harmful effects on human health, biota, and coastal ecosystems. However, limited information is available on the degradation behavior of plastics, especially biodegradable ones, in dune habitats. Moreover, the effects of plastics on dune plant growth and ability to withstand environmental stresses and invasion by non-native plants have been largely neglected. This is a particularly relevant issue since biological invasions are major threats to dune ecosystems. In this 18-month study, we examined the degradation behavior of two plastic bags, non-biodegradable (NBP) or biodegradable/compostable (BP), in the dune environment by visual observations and analytical techniques. Concomitantly, we investigated the individual and combined effects of bag type and sand burial (no burial vs. partial burial) on the performance of a native dune plant (Thinopyrum junceum) and an invasive plant (Carpobrotus sp.) and on their interaction. NBP did not show relevant degradation signs over the experimental period as expected. BP exhibited gradual surface modifications and changes in chemical functionality and were almost disintegrated after 18 months. Bags and burial reduced independently T. junceum survival and growth, and most plants died within 8 months of plastic exposure. Bags and burial did not affect Carpobrotus survival. However, burial decreased Carpobrotus growth while NBP increased it. Both plastics increased Carpobrotus competitive ability, and no T. junceum plants survived to co-occurrent Carpobrotus, BP, and burial. These findings indicate that removing all littered plastics from beach-dune systems not only is critical to reduce plastic pollution but also to prevent further spread of invasive species in coastal dunes.

Starting from bioethanol it is possible, by using an appropriate catalyst, to produce ethyl acetate in a single reaction step and pure hydrogen as a by-product. Two molecules of hydrogen can be obtained for each molecule of ethyl acetate produced. The mentioned reaction is reversible, therefore, it is possible to hydrogenate ethyl acetate to reobtain ethanol, so closing the chemical cycle of a Liquid Organic Hydrogen Carrier (LOHC) process. In other words, bioethanol can be conveniently used as a hydrogen carrier. Many papers have been published in the literature dealing with both the ethanol dehydrogenation and the ethyl acetate hydrogenation to ethanol so demonstrating the feasibility of this process. In this review all the aspects of the entire LOHC cycle are considered and discussed. We examined in particular: the most convenient catalysts for the two main reactions, the best operative conditions, the kinetics of all the reactions involved in the process, the scaling up of both ethanol dehydrogenation and ethyl acetate hydrogenation from the laboratory to industrial plant, the techno-economic aspects of the process and the perspective for improvements. In particular, the use of bioethanol in a LOHC process has three main advantages: (1) the hydrogen carrier is a renewable resource; (2) ethanol and ethyl acetate are both green products benign for both the environment and human safety; (3) the processes of hydrogenation and dehydrogenation occur in relatively mild operative conditions of temperature and pressure and with high energetic efficiency. The main disadvantage with respect to other more conventional LOHC systems is the relatively low hydrogen storage density.

The transition from fossil resources to renewable ones represents an urgent need. Biomasses are promising feedstocks, potentially exploitable through novel bio-catalytic processes, such as acidogenic fermentation to carboxylic acids, which can be further converted into more value-added bio-products through cascade chemical approaches, such as hydrogenation to corresponding alcohols/esters. In this work, the optimization of the hydrogenation of commercial hexanoic acid to 1-hexanol and hexyl hexanoate was first investigated. For this purpose, 5 wt% Re/C resulted active and selective towards 1-hexanol production. The same catalyst was further tested for the hydrogenation of crude hexanoic acid, obtained by fermentation of red and white grape pomaces. Hydrogenation of these crude hexanoic acid mixtures confirmed the promising performances of 5 wt% Re/C, achieving the complete substrate conversion with a prevailing selectivity to 1-hexanol (~58 mol%), rather than to hexyl hexanoate (~30 mol%). Moreover, the use of an acid support, such as Al2O3, markedly shifted the selectivity towards hexyl hexanoate (~51 mol%). This observation was further demonstrated by testing physical mixtures of 5 wt% Re/C and different amounts of acidic niobium phosphate. Based on these promising results, exploitation of grape pomace for 1-hexanol/hexyl hexanoate production, to use as bio-fuels or bio-solvents, represents a smart possibility., Proceedings of the 30th European Biomass Conference and Exhibition, 9-12 May 2022, Online, pp. 494-500

Platinum-group element (PGE) geochemistry of arc-related magmas can be used to constrain the timing of sulfide saturation, which plays a critical role in the chalcophile element fertility of evolving magmatic systems. In this study, we provide new major and trace elements, PGE, Re and Au data for the shoshonitic suite (from basalt to rhyolite) of the active volcanic system of Vulcano (Aeolian Islands, Italy), an excellent study case for investigating mineralizing processes in arc volcanoes. The most primitive magma erupted at Vulcano is characterized by fractionation of Ir-group PGE (Ir, Os, Ru) relative to the Pd-group PGE (Pd, Pt, Rh), which is attributed to the magma being saturated with a Pt-rich alloy and possibly spinel and Os–Ir alloy. A negative Au anomaly, shown by Vulcano magmas, suggests that the Au was lost to an early exsolved S– (and moderately Cl–) rich fluid phase that, upon migration to higher levels of the feeding system, could have enhanced the mineralizing potential of the magmatic system. The Pd content of Vulcano primitive magmas is high (~ 8 ppb) and comparable to values found in other arc-related mineralized systems. The early Pd depletion, relative to Au and Cu, during evolution towards more evolved magmas, suggests that the magmatic system reached sulfide saturation at about 4 wt.% MgO. Chalcophile element fractionation modeling shows that the immiscible sulfide mass proportion was initially very low (~ 0.0015%), and gradually increased to about 0.1% at about 2 wt.% MgO, causing a late depletion of the less compatible chalcophile elements, including Cu. A significant chalcophile metal depletion in the silicate melt occurred once sulfide saturation was achieved, well before hydrosaline fluid exsolution at

The depletion of fossil resources makes the transition towards renewable ones more urgent. For this purpose, the synthesis of strategic platform-chemicals, such as 5-hydroxymethylfurfural (HMF), represents a fundamental challenge for the development of a feasible bio-refinery. HMF perfectly deals with this necessity, because it can be obtained from the hexose fraction of biomass. Thanks to its high reactivity, it can be exploited for the synthesis of renewable monomers, solvents, and bio-fuels. Sustainable HMF synthesis requires the use of waste biomasses, rather than model compounds such as monosaccharides or polysaccharides, making its production more economically advantageous from an industrial perspective. However, the production of HMF from real feedstocks generally suffers from scarce selectivity, due to their complex chemical composition and HMF instability. On this basis, different strategies have been adopted to maximize the HMF yield. Under this perspective, the properties of the catalytic system, as well as the choice of a suitable solvent and the addition of an eventual pretreatment of the biomass, represent key aspects of the optimization of HMF synthesis. On this basis, the present review summarizes and critically discusses the most recent and attractive strategies for HMF production from real feedstocks, focusing on the smartest catalytic systems and the overall sustainability of the adopted reaction conditions.

The ruthenium compounds [(η6-p-cymene)RuCl{κ2N-(HCNR)2}]NO3 (R = 4-C6H4Me, [1]NO3; 4-C6H4OH, [2]NO3; C6H11Cy, [3]NO3; 4-C6H10OH, [4]NO3; tBu, [5]NO3) were prepared in high yields from [(p-cymene)RuCl2]2, AgNO3 and the appropriate α-diimine. Compounds [2]PF6 and [4]PF6 were obtained by a straightforward reaction of [(η6-p-cymene)RuCl(MeCN)0.66]PF6, [6]PF6, with α-diimine, whereas [4]BPh4 was obtained by metathesis between [4]NO3 and NaBPh4. All the ruthenium products were characterized by analytical methods, IR, NMR and UV-Vis spectroscopy; in addition, the structure of [1]NO3 was ascertained by an X-ray diffraction study. Compounds [1–4]NO3, [4]PF6 and [4]BPh4 were investigated as catalytic precursors in the transfer hydrogenation reaction of ethyl levulinate to γ-valerolactone in isopropanol solution under microwave irradiation. [4]BPh4 was revealed to be the best catalytic precursor, affording γ-valerolactone in 62% yield under optimized experimental conditions.

Spectacular volcanic landforms characterize the Miocene lava flows and ignimbrites forming San Pietro Island (Sardinia, Italy). The island, furthermore, is a site of volcanic-hosted manganese mineralizations, which have been exploited until the past century. These geological features, set in a fascinating landscape context, represent a volcanic and mining geoheritage which could be valorized in terms of sustainable geotourism and scientific outreach. In this paper, we examine potential sites of volcanological and mining geoheritage interest of San Pietro Island, some of which are part of the Italian Geosite Inventory. We update the scientific description of geological features according to the most recent research results, because we consider that a geosite description should evolve along with the development of scientific understanding. Also, we present some new potential geosites, with a discussion of their scientific relevance and geotouristic potential. Three geo-volcanological features are identified: the spectacular megafolding structures of the comenditic lava flows, some peculiar and uncommon degassing features of ignimbrites, and the volcanic-hosted manganese mineralizations and the related mining heritage. Based on this, four geosites are proposed and described: Becco Nasca (lava flow folding), Cala Fico (lava flow folding and mining heritage), La Punta (degassing features of ignimbrites), and La Piramide (mining heritage). Some actions are suggested to promote the valorization of the geological and mining features of these geosites for geotourism and scientific outreach, and to raise awareness of these geoheritage values among the general public.

A large fraction of plastic litter found in natural environments is constituted by conventional not biodegradable plastic bags, and their adverse effects via ingestion or entanglement on terrestrial and marine organisms are largely documented. Biodegradable and compostable shoppers have been recently developed as alternative to traditional ones. These bags are specifically designed to degrade in composting facilities and generate a product devoid of toxicity to soils and crops. However, very little is known on the effects of bag leaching, i.e. the transfer of chemicals from plastic into natural environments, on vegetation. Some plant species are highly sensitive to a variety of chemicals, and seedling growth is generally the most affected life history stage. In this study we assessed the potential effects of conventional (high-density polyethylene, HDPE) and compostable (Mater-bi®, MB) bags, when left in natural environments, on water quality and plant development. To this end, seeds of Lepidium sativum L., a terrestrial plant commonly used in phytotoxicity standard tests, were exposed to leachates obtained from different amount of HDPE and MB bags, simulating various pollution degrees occurring in nature, for 72 h. Both not-exposed (or virgin) bags and natural weathering exposed bags were used. Variations of chemical-physical characteristics of extracts were used as indicative of water quality deterioration, while alterations of seed gemination and seedling radicle and hypocotyl length were considered as indicative of phytotoxicity. A chemical qualitative screening of the leachates was also performed to identify the compounds with potential phytotoxicity. Both types of bags affected water characteristics (pH, salinity and total dissolved solids) relevant to plants, and released into water intentionally added chemicals, such as the noxious bisphenol A, and other phytotoxic substances probably generated during bag manufacturing. Leachates from both bag types did not affect seed germination. But, a significant number of seedlings showed developmental abnormalities or reduced seedling growth. The hypocotyl was the most sensible seedling organ to HDPE bag leachates while the radicle was the most vulnerable to MB ones. These findings indicate that plastic bags, including those that meet biodegradability and compostability standards, represent a potential threat to plants, if left in natural environments. Therefore, people and managers should be adequately informed about the potential environmental impact of an incorrect bag disposal. Simple, rapid standard phytotoxicity tests, such as the L. sativum bioassay, applied to bag leachates could be used in the future to select not noxious additives so to develop more eco-friendly bags.

5-Hydroxymethyl-2-furaldehyde (HMF) is one of the top 12 biobased chemicals, precursor of renewable monomers and biofuels. This key molecule can be obtained from the dehydration of monosaccharides ...

In the Iano area (Southern Tuscany) a small tectonic window of Tuscan metamorphic units is observed. This belongs to the northernmost part of the so-called Mid-Tuscan ridge and, during Pliocene, formed a submarine high, now defining the easternmost shoulder of the Volterra Pliocene basin. The area gives the opportunity to investigate the complete cycle of negative inversion from crustal thickening to crustal thinning, which characterizes Southern Tuscany. Our new data focus on the western margin of the Iano ridge, and in particular on a system of high angle normal faults that represents the youngest structures of the investigated area. These structures, deformed low angle regional detachments locally juxtaposing the uppermost units of contractional nappe stack (the ophiolite-bearing Ligurian units), with the Tuscan metamorphic units, with an almost complete excision of at least 3.5 Km thick Mesozoic to Tertiary Tuscan nappe succession. The high angle normal faults show variable Plio-Quaternary vertical displacements from few meters to about 500 meters, and acted as pathways for the upwelling of hydrothermal fluids, as revealed by Pleistocene travertine deposits, hydrothermal alteration and occurrence of different generations of fluid inclusions in hydrothermal veins associated with these fault systems. Fluid inclusions were studied in quartz veins hosted in the Verrucano metasediments forming the top of the Tuscan metamorphic unit, as well as in some carbonate lithotypes (Cretaceous to Tertiary in age) of the overlying Tuscan Nappe. Two different kinds of fluid inclusions were documented. The Type 1 are multiphase (liquid + vapor + 1 daughter mineral) liquid-rich fluid inclusions whereas the Type 2 are two-phase (liquid + vapor) liquid-rich fluid inclusions. Type 1 fluid inclusions are primary in origin and were found only in quartz veins present in Verrucano metarudites, whereas Type 2 fluid inclusions occur in quartz veins present in both Verrucano phyllites and quartzites and in the carbonate units of the Tuscan Nappe. These are secondary and can be furthermore distinguished in two sub-populations (Type 2a and Type 2b) on the basis of petrographic observation and microthermometric data. Fluid inclusion investigation evidenced an evolution of the hydrothermal fluids from relatively high-T (~265°C) and hypersaline (35 wt.% NaClequiv.) fluids trapped at about 100 MPa, to lower temperature (~195°C) and salinity (~9.5 wt.% NaClequiv.) fluids, having circulated in the high-angle fault system. Based on the new data and a revision of the local tectonic setting a fluid-rock interaction history has been reconstructed with new hints and constraints for the Plio-Quaternary extensional history of the Volterra basin.