Search

Background. The impact of spontaneous portosystemic shunts (SPSSs) on natural history of cirrhotic patients was recently evaluated through the measurement of total shunt area (TSA), a novel tool that allows a comprehensive assessment of SPSSs extension, identifying a direct correlation of higher TSA with lower patient survival. The role of SPSSs in liver transplant (LT) is still debated: we sought to investigate the clinical impact of TSA on the development of early allograft dysfunction (EAD), acute kidney injury (AKI), postoperative complications, and graft and patient survival following LT. Methods. Preoperative imaging of 346 cirrhotic patients undergoing primary LT between 2015 and 2020 were retrospectively revised, recording the size and anatomy of each SPSS to calculate TSA. The impact of TSA and selected patient and donor characteristics on the development of EAD, AKI, and clinically relevant complications was evaluated through univariate and multivariate logistic regression, whereas their effect on graft and patient survival was investigated through Cox regression analysis. Results. A TSA exceeding 78.54 mm2resulted as an independent risk factor for the development of EAD (odds ratio [OR]: 2.327; P = 0.003), grade 3 AKI (OR: 2.093; P = 0.041), and clinically relevant complications (OR: 1.962; P = 0.015). Moreover, higher TSA was significantly related to early graft and patient survivals, emerging as an independent risk factor for 12-mo graft loss (hazard ratio: 3.877; P = 0.007) and patient death (hazard ratio: 2.682; P = 0.018). Conclusions. Higher TSA emerged as a significant risk factor for worse postoperative outcomes following LT, supporting the need for careful hemodynamic assessment and management of patients presenting multiple/larger shunts.

CO2 sorption–desorption cycles with a methyldiethanolamine (MDEA)/piperazine (PZ) blend have been performed with a rotoevaporator. Similar to other CO2 separation technologies, the heating involved in MDEA/PZ solvent regeneration is the most energy-intensive step in the overall CO2 separation process. Thus, this study investigated the desorption kinetics under low-pressure (

Municipal solid waste incineration fly ash (MSWI-FA) is one of the solid by-products of MSWI treatment, accounting for about 1–3% of the total incinerated waste. FA forms in the plant purification system and bears important amount of heavy metals and salt (chloride and sulphate), therefore it is considered as hazardous waste (Bernasconi et al, 2022). For this reason, FA is required to undergo stabilization/inertization treatment (one of the most common is water washing), before being landfilled or used as secondary/supplementary raw materials. In this latter case, few studies have evaluated the incorporation of waste residues into magnesium potassium phosphate cements (MKPCs), mainly focussing on coal fly ash and grounded blast furnace slag (Gardner et al., 2015; Xu et al, 2017). They represent an example of chemically-bonded ceramics, in which the hardening occurs at room temperature through the acid-base aqueous reaction between an alkaline magnesia source (MgO) and a phosphate source (KDP, KH2PO4), according to the following chemical equation:MgO + KH2PO4 + 5H2O → MgKPO4·6H2O (K-struvite)This reaction is fast, exothermic and its mechanism has been described as a multi-step process (Viani et al., 2018). MKPCs are receiving increasing interest because of their excellent properties, namely high early age and long-term strengths, resistance to sulphate attack, rapid setting, near-neutral pH, low shrinkage (Xu et al, 2017). However, there are also some drawbacks, mainly related to the fast kinetics and expensive cost of the starting materials, since MgO needs to be calcinated at high temperature (at least 1500°C). The introduction of FA would be economically beneficial both by reducing the amount of MgO needed and providing a destination for a waste residue which otherwise would require important management costs.In this work, the incorporation of washed MSWI-FA into MKPC is studied, paying major attention on how and in what extent MSWI-FA participates in the cement reaction. Indeed, an approach similar to the one adopted by Xu et al is employed, where the design strategy takes into account the reactivity of MSWI-FA. In particular, one formulation treats MSWI-FA as fully inert, replacing both magnesia and KDP, while in another one MSWI-FA is considered as fully reactive, thus replacing magnesia only. The obtained cement pastes are thoroughly characterized by employing spectroscopic (SSNMR, Zn K-edge XANES), X-ray diffraction, SEM-EDS and isocalorimetry techniques. ReferencesD. Bernasconi, C. Caviglia, E. Destefanis, A. Agostino, R. Boero, N. Marinoni, C. Bonadiman, A. Pavese. Influence of speciation distribution and particle size on heavy metal leaching from MSWI fly ash, Waste Management, 138 (2022), 318-327. L.J. Gardner, S.A. Bernal, S.A. Walling, C.L. Corkhill, J.L. Provis, N.C. Hyatt. Characterisation of magnesium potassium phosphate cements blended with fly ash and ground granulated blast furnace slag, Cement and Concrete Research, 74 (2015), 78-87. B. Xu, H. Ma, H. Shao, Z. Li, B. Lothenbach. Influence of fly ash on compressive strength and micro-characteristics of magnesium potassium phosphate cement mortars. Cement and Concrete Research, 99 (2017), 86-94. A. Viani, P. Mácová. Polyamorphism and frustrated crystallization in the acid–base reaction of magnesium potassium phosphate cements, CrystEngComm, 20 (2018), 4600.

Calcium oxalates are naturally occurring biominerals and can be found as a byproduct of some industrial processes. Recently, a new and green method for carbon capture and sequestration in stable calcium oxalate from oxalic acid produced by carbon dioxide reduction was proposed. The reaction resulted in high-quality weddellite crystals. Assessing the stability of these weddellite crystals is crucial to forecast their reuse as solid-state reservoir of pure CO2 and CaO in a circular economy perspective or, eventually, their disposal. The thermal decomposition of weddellite obtained from the new method of carbon capture and storage was studied by coupling in-situ high-temperature X-ray powder diffraction and thermogravimetric analysis, in order to evaluate the dehydration, decarbonation, and the possible production of unwanted volatile species during heating. At low temperature (119–255 °C), structural water release was superimposed to an early CO2 feeble evolution, resulting in a water-carbon dioxide mixture that should be separated for reuse. Furthermore, the storage temperature limit must be considered bearing in mind this CO2 release low-temperature event. In the range 390–550 °C, a two-component mixture of carbon monoxide and dioxide is evolved, requiring oxidation of the former or gas separation to reuse pure gases. Finally, the last decarbonation reaction produced pure CO2 starting from 550 °C.

Lymph nodes (LNs)’ metastases have a well-known detrimental impact on the survival outcomes of patients suffering from pancreatic cancer of the body and tail. However, the extent of the lymphadenectomy for this tumor location is still debated. The aim of this study was to systematically review the current literature to explore the incidence and the prognostic impact of non-peripancreatic lymph nodes (PLNs) in patients suffering from pancreatic cancer of the body and tail. A systematic review was conducted according to PRISMA and MOOSE guidelines. The primary endpoint was to assess the impact of non-PLNs on overall survival (OS). As a secondary endpoint, the pooled frequencies of different non-PLN stations’ metastatic patterns according to tumor location were explored. Eight studies were included in data synthesis. An increased risk of death for patients with positive non-PLNs was detected (HR: 2.97; 95% CI: 1.81–4.91; p < 0.0001). Meta-analysis of proportions pointed out a 7.1% pooled proportion of nodal infiltration in stations 8–9. The pooled frequency for station 12 metastasis was 4.8%. LN stations 14–15 were involved in 11.4% of cases, whereas station 16 represented a site of metastasis in 11.5% of cases. Despite its potential beneficial effect on survival outcome, a systematic extended lymphadenectomy could not be recommended yet for patients suffering from PDAC of the body/tail.

Municipal solid waste incineration fly ash (MSWI-FA) is one of the solid by-products of MSWI treatment, accounting for about 1–3% of the total incinerated waste. FA forms in the plant purification system and bears important amount of heavy metals and salt (chloride and sulphate), therefore it is considered as hazardous waste (Bernasconi et al, 2022). For this reason, FA is required to undergo stabilization/inertization treatment (one of the most common is water washing), before being landfilled or used as secondary/supplementary raw materials. In this latter case, many studies have evaluated the incorporation of FA into alkali silicate-based geopolymer. This material is obtained by the reaction between an aluminosilicate source (metakaolin, MTK) and alkali hydroxide (NaOH, KOH), to obtain polymer-like condensation product (Wang et al, 2019). This material is characterized by higher durability and greenness with respect to the conventional Portland cement (OPC), thus gaining interest recently as a promising partial substitute to OPC. On the other hand, much less attention has been focused on acid-based geopolymer, in which the alkali hydroxide is substituted by phosphoric acid, thus producing an Al-O-P/Si-O-P polymeric matrix (Wang et al, 2019). This material has displayed better performance than the traditional alkali-silicate geopolymer, in terms of corrosion resistance (Wagh et al, 2011), thermal stability (Celerier et al, 2019) and mechanical strength. However, there are also some drawbacks, mainly related to the expensive cost of the starting materials, since MTK is obtained by high-temperature (750°C) calcination of kaolinite. The introduction of FA would be economically beneficial both by reducing the amount of MTK needed and providing a destination for a waste residue which otherwise would require important management costs.In this work, (previously washed) FA partial replacement of MTK has been tested in the phosphate-based geopolymer formulation, up to 50 wt%. Different synthesis conditions have been evaluated, in terms of Al/P molar ratio, liquid-to-solid ratio and curing temperature. The resulting reaction products have been investigated by a combined analytical approach, involving spectroscopies (ATR-FTIR and Solid-state NMR) and powder X-ray diffraction techniques, while their morphology was inquired by SEM-EDS analysis. Moreover, compressive strength tests have been employed to evaluate the mechanical properties, which demonstrated the good performances of FA blended phosphate-based geopolymers, with compressive strength values over 30 MPa. ReferenceD. Bernasconi, C. Caviglia, E. Destefanis, A. Agostino, R. Boero, N. Marinoni, C. Bonadiman, A. Pavese. Influence of speciation distribution and particle size on heavy metal leaching from MSWI fly ash, Waste Management, 138 (2022), 318-327. Y. Wang, Y. Alrefaei, J. Dai. Silico-Aluminophosphate and Alkali-Aluminosilicate Geopolymers: A Comparative Review, Frontiers in Materials, 6 (2019), 106. A.S. Wagh. Phosphate geopolymers, Ceramic Engineering and Science Proceeding, 32, 10 (2011), 91-103. H. Celerier, J. Jouin, A. Gharzouni, V. Mathivet, I. Sobrados, N. Tessier-Doyen, S. Rossignol. Relation between working properties and structural properties from 27Al, 29Si and 31P NMR and XRD of acid-based geopolymers from 25 to 1000 °C, Materials Chemistry and Physics, 228 (2019), 293-302.

This work is focused on the possible reutilization of municipal solid waste incinerator (MSWI) fly ash as a metakaolin replacement in the acid-based geopolymer. This type of geopolymer, obtained by the reaction between an aluminosilicate source (metakaolin) and phosphoric acid to form an Al-O-P/Si-O-P matrix (Wang et al, 2019), have displayed better performance than the traditional alkali-silicate geopolymer, in terms of corrosion resistance (Wagh et al, 2011), thermal stability and mechanical strength (Celerier et al, 2019). The replacement of up to 30 % wt has proved to not significantly alter the remarkable performance of the material, obtaining compressive strength values higher than 30 MPa. However, since fly ash contains dangerous substances as chlorides, sulfates, and heavy metals, which must be stabilized, it is important to evaluate the leching stability of the final materials.Therefore, test cube blocks of 1x1x1 cm size, containing 10, 20 and 30 % wt of previously washed fly ash replacement with respect to metakaolin are prepared, with Al/P molar ratio of 1, liquid-to-solid ratio raging from 0.95-1 and 3 days at 60°C as curing temperature. Leaching tests, according to the European standards EN-12457 (2002), using deionized water at a ratio liquid to solid of 10, are applied to geopolymers blocks to evaluate the concentration of salts and heavy metals that usually exceeds the law threshold in the raw fly ash. Leachates are analyzed by ionic chromatography and ICP-MS: the results show that the concentrations of chlorides are under the legislation limits provided for not dangerous waste, as well as sulfates and fluorides; relatively to heavy metals Zn, Pb, Cd exceed the concentrations limits. Further tests and analyses are carried out to evaluate the impact of synthesis parameters on the leaching stability of these materials. Reference Wang, Y. Alrefaei, J. Dai. Silico-Aluminophosphate and Alkali-Aluminosilicate Geopolymers: A Comparative Review, Frontiers in Materials, 6 (2019), 106. A.S. Wagh. Phosphate geopolymers, Ceramic Engineering and Science Proceeding, 32, 10 (2011), 91-103. Celerier, J. Jouin, A. Gharzouni, V. Mathivet, I. Sobrados, N. Tessier-Doyen, S. Rossignol. Relation between working properties and structural properties from 27Al, 29Si and 31P NMR and XRD of acid-based geopolymers from 25 to 1000 °C, Materials Chemistry and Physics, 228 (2019), 293-302.

Municipal solid waste incineration fly ash (FA) can represent a sustainable supply of supplementary material to the construction industries if it is pre-treated to remove hazardous substances such as chloride, sulfate, and heavy metals. In this paper, the phenomenology associated with a water washing multi-cycle treatment of FA is investigated, focusing attention upon the mineral dissolution process. The efficacy of the treatment is assessed by leaching tests, according to the European Standard, and discussed in light of the occurring mineral phases. The water-to-solid (L/S) ratio is a crucial parameter, along with the number of washing cycles, for removing halite and sylvite, whereas quartz, calcite, anhydrite, and an amorphous phase remain in the solid residue. The sequential extraction method and dissolution kinetics modelling provide further elements to interpret leaching processes, and suggest that dissolution takes place through a two-step mechanism. Altogether, multi-step washing with L/S = 5 is effective in reducing contaminants under the legal limits for non-hazardous waste disposal, while the legal limits for non-reactive or reusable material cannot be completely reached, owing to sulfate and some heavy metals which still leached out from the residue.

BACKGROUND The risk of adverse cardiovascular events in patients with acute myocarditis (AM) and desmosomal gene variants (DGV) remains unknown.OBJECTIVES The purpose of this study was to ascertain the risk of death, ventricular arrhythmias, recurrent myocarditis, and heart failure (main endpoint) in patients with AM and pathogenic or likely pathogenetic DGV.METHODS In a retrospective international study from 23 hospitals, 97 patients were included: 36 with AM and DGV (DGV[+]), 25 with AM and negative gene testing (DGV[-]), and 36 with AM without genetics testing. All patients had troponin elevation plus findings consistent with AM on histology or at cardiac magnetic resonance (CMR). In 86 patients, CMR changes in function and structure were re-assessed at follow-up.RESULTS In the DGV(+) AM group (88.9% DSP variants), median age was 24 years, 91.7% presented with chest pain, and median left ventricular ejection fraction (LVEF) was 56% on CMR (P = NS vs the other 2 groups). Kaplan-Meier curves demonstrated a higher risk of the main endpoint in DGV(+) AM compared with DGV(-) and without genetics testing patients (62.3% vs 17.5% vs 5.3% at 5 years, respectively; P < 0.0001), driven by myocarditis recurrence and ventricular arrhythmias. At follow-up CMR, a higher number of late gadolinium enhanced segments was found in DGV(+) AM. CONCLUSIONS Patients with AM and evidence of DGV have a higher incidence of adverse cardiovascular events compared with patients with AM without DGV. Further prospective studies are needed to ascertain if genetic testing might improve risk stratification of patients with AM who are considered at low risk. (J Am Coll Cardiol HF 2022;10:714-727) (c) 2022 by the American College of Cardiology Foundation.

The two most common polymorphs of MnO2, ramsdellite and pyrolusite, are often found in natural association. Our starting sample is from the Mistake mine (Arizona) containing macroscopic crystals of both ramsdellite (a = 4.5131(6), b = 9.2689(13), c = 2.8610(4) A, V = 119.69(3) A3; S.G. Pbmn) and pyrolusite (a = 4.4030(2), c = 2.87392(16) A, V = 55.715(5) A3; S.G. P42/mnm), along with a smaller amount of “groutellite”. A mixed powder was used to study the ramsdellite→pyrolusite transformation by in situ high-temperature X-ray powder diffraction. Our results reveal that this transformation is not a direct transition, but it occurs in two steps, as a function of temperature; ramsdellite transforms into an amorphous phase, which then recrystallizes into pyrolusite. Amorphization of ramsdellite and crystallization of pyrolusite kinetics were studied by the universal equation for solid–solid reactions. The two activation energies are comparable, but the pre-exponential factor of the ramsdellite amorphization is two orders of magnitude larger than pyrolusite crystallization’s. As a consequence, ramsdellite→pyrolusite transformation implies the formation of an amorphous transition, due to a mismatch between the conversion rates, that reaches its maximum at around 630 K and then decreases at higher T, when pyrolusite crystallization is strongly promoted.

Fly ash from municipal solid waste incineration (MSWI-FA) contains leachable heavy metals. In the present study the correlations between heavy metal content, particle size, speciation distribution with respect to water leaching are investigated, using a combination of solid-state bulk analytical techniques, leaching treatments, sequential extractions and thermodynamic geochemical modelling. Among the analyzed heavy metals, Zn and Pb are the most abundant in any grain size class, followed by Cu, Cr, Cd and Ni, with concentration that tends to increase with a decrease of the grain size. The phase composition is constituted of salt (halite, sylvite, anhydrite and syngenite), which provide the main minerals regardless of the particle size class; calcite, quartz and gehlenite occur in comparatively lower amounts, while 50% wt is composed of amorphous fraction. Heavy metal leaching is strongly correlated to speciation distribution, and in particular to the fraction (F1) associated with salt, carbonate and weak surface sorption. Leaching from speciation due to surface complexation on Al/Fe (hydr)oxide becomes relevant at acidic regime. Particle size and heavy metal content, in turn, moderately correlate with leaching. The F1-speciation as a function of particle size does not exhibit a definite trend shared by all heavy metals under investigation. This suggests that i) differences in speciation distribution, rather than bare heavy metal content or particle size, govern leaching from MSWI-FA; ii) F1 can be regarded as a marker of the potential heavy metal leaching; iii) a comparatively modest efficiency in managing MSWI-FA is expected from grain size separation strategies.

Municipal solid waste incinerator (MSWI) fly ash can represent a sustainable source of construction materials, but it needs to be treated in order to remove dangerous substances as chlorides, sulfates, and heavy metals. The concentration of salts and heavy metals in fly ash usually exceeds the law threshold and so they are considered a hazardous waste, unsuitable for reuse in concrete and civil engineering applications.In this work, a complete characterization of fly ash coming from a northern Italy thermovalorization plant was investigated, both on the solid and leachates composition, focused on the particle size, by X-Ray fluorescence and X-Ray diffraction on the solid matrices and ICP-MS analysis on the leachates.Using mechanical sieving on several subsamples of fly ash, six different particle size were separated and analyzed, and compared to the bulk fly ash composition.The most abundant elements are represented by Ca, Cl, S, and Si; trace elements and heavy metals are mainly represented by Zn, Fe, Al, Pb. The XRF and ICP-MS analysis show a general increasing trend, as the particle size decrease, of Na, K, Cl, S, as well as Cr, Cd, Cu, Pb, Sb, Zn, Ba, both on solid and leachates composition; on the contrary Ca and Si decrease.After leaching Cl and K decrease consistently, while it can be observed an increase of all the other elements, due to the weight loss attributable mainly to the leaching of Na-K chlorides, that is confirmed also by the X-Ray diffraction analysis.

Summary Background Elevated proinflammatory cytokines are associated with greater COVID-19 severity. We aimed to assess safety and efficacy of sarilumab, an interleukin-6 receptor inhibitor, in patients with severe (requiring supplemental oxygen by nasal cannula or face mask) or critical (requiring greater supplemental oxygen, mechanical ventilation, or extracorporeal support) COVID-19. Methods We did a 60-day, randomised, double-blind, placebo-controlled, multinational phase 3 trial at 45 hospitals in Argentina, Brazil, Canada, Chile, France, Germany, Israel, Italy, Japan, Russia, and Spain. We included adults (≥18 years) admitted to hospital with laboratory-confirmed SARS-CoV-2 infection and pneumonia, who required oxygen supplementation or intensive care. Patients were randomly assigned (2:2:1 with permuted blocks of five) to receive intravenous sarilumab 400 mg, sarilumab 200 mg, or placebo. Patients, care providers, outcome assessors, and investigators remained masked to assigned intervention throughout the course of the study. The primary endpoint was time to clinical improvement of two or more points (seven point scale ranging from 1 [death] to 7 [discharged from hospital]) in the modified intention-to-treat population. The key secondary endpoint was proportion of patients alive at day 29. Safety outcomes included adverse events and laboratory assessments. This study is registered with ClinicalTrials.gov, NCT04327388; EudraCT, 2020-001162-12; and WHO, U1111-1249-6021. Findings Between March 28 and July 3, 2020, of 431 patients who were screened, 420 patients were randomly assigned and 416 received placebo (n=84 [20%]), sarilumab 200 mg (n=159 [38%]), or sarilumab 400 mg (n=173 [42%]). At day 29, no significant differences were seen in median time to an improvement of two or more points between placebo (12·0 days [95% CI 9·0 to 15·0]) and sarilumab 200 mg (10·0 days [9·0 to 12·0]; hazard ratio [HR] 1·03 [95% CI 0·75 to 1·40]; log-rank p=0·96) or sarilumab 400 mg (10·0 days [9·0 to 13·0]; HR 1·14 [95% CI 0·84 to 1·54]; log-rank p=0·34), or in proportions of patients alive (77 [92%] of 84 patients in the placebo group; 143 [90%] of 159 patients in the sarilumab 200 mg group; difference −1·7 [−9·3 to 5·8]; p=0·63 vs placebo; and 159 [92%] of 173 patients in the sarilumab 400 mg group; difference 0·2 [−6·9 to 7·4]; p=0·85 vs placebo). At day 29, there were numerical, non-significant survival differences between sarilumab 400 mg (88%) and placebo (79%; difference +8·9% [95% CI −7·7 to 25·5]; p=0·25) for patients who had critical disease. No unexpected safety signals were seen. The rates of treatment-emergent adverse events were 65% (55 of 84) in the placebo group, 65% (103 of 159) in the sarilumab 200 mg group, and 70% (121 of 173) in the sarilumab 400 mg group, and of those leading to death 11% (nine of 84) were in the placebo group, 11% (17 of 159) were in the sarilumab 200 mg group, and 10% (18 of 173) were in the sarilumab 400 mg group. Interpretation This trial did not show efficacy of sarilumab in patients admitted to hospital with COVID-19 and receiving supplemental oxygen. Adequately powered trials of targeted immunomodulatory therapies assessing survival as a primary endpoint are suggested in patients with critical COVID-19. Funding Sanofi and Regeneron Pharmaceuticals.

The management of waste and its sustainable reuse is one of the most important concern in our society in recent years, together with the increasing need to find primary materials without resorting to new extraction of resources. In this context, the thermovalorization of municipal solid waste (MSW) is currently the method that is spreading and replacing landfill disposal; the thermal treatment allows to reduce the volumes significantly, producing energy and returning bottom ashes (BA) and fly ashes (FA) in the measure of 20% and 5% of the total waste respectively.The MSW incineration BA are classified as non-hazardous waste and can be reused as a raw material after some physical-chemical treatments.The FA, on the contrary, are classified as hazardous waste and according to current legislation, they are usually subjected to vitrification treatments and stored in dedicated landfills. The hazard is due to the high content of soluble salts (chlorides and sulfates) and heavy metals (mainly Zn and Pb). Therefore, for their possible reuse as construction materials (e.g. ceramic, cement, concrete aggregates) or base roads, a preliminary stabilization step is required which often requires the use of significant quantities of energy.In the present work, low energy cost methods are considered to reduce the dangerousness of FA and consequently make them more easily treatable for their reintegration into the production cycles.Among the methods, washing of FA with water is examined, to find the lowest L / S ratio in the reduction of salts and heavy metals, analyzing the dissolution kinetics and the mineralogical content of fly ash before and after each washing treatment.For a better definition of the kinetics, the FA are previously submitted to particle size separation to understand in which fractions the most dangerous substances are concentrated.Washing treatments can be useful to remove or reduce soluble salts, in particular chlorides, by using a different liquid / solid (L / S) ratio, in order to obtain a more suitable material for the solidification / stabilization treatments carried out by geopolymerization or in cement.The eluates of washing are also taken into consideration to evaluate the recovery of elemental species of interest and the purification of the liquid phase with biochar.

Carbon dioxide is a greenhouse gas and a natural component of the atmosphere, essential for plant life. Natural reservoirs (oceans, soils, etc.) regulate its geochemical cycle, but the anthropic activity disturbs this balance. In order to control the concentration of carbon dioxide in the atmosphere, many synergic CO2 capture and sequestration methods (Aresta and Dibenedetto, 2007; Bachu, 2008; Baker et al., 2007; García-España et al., 2004; Lively et al., 2015; Rosa et al., 2018; Stenhouse et al., 2009)coupled with the reduction of carbon dioxide emissions in the atmosphere, have been proposed.In an early paper (Pastero et al., 2019), we proposed the ascorbic acid (vitamin C) as a high-performance and green CO2 scrubber. We hypothesized a red-ox reaction involving calcium ascorbate as the sacrificial reductant. As a result, the reduction of carbon from C(IV) to C(III) leads to the formation of oxalic acid and, in the presence of calcium as the counterion, to the precipitation of calcium oxalate. Calcium oxalate is an almost insoluble salt that doubles the capture efficiency with respect to calcium carbonate. The reaction’s performance in terms of carbon capture efficiency was evaluated under different experimental conditions. Depending on the experimental setup, the yield of the capture and sequestration reaction reaches very high values, up to 80%. The return of the system depends on the total surface exposed to the reaction, the CO2/vitamin C mixing mode, the presence of oxygen in the reaction vessel, and the stoichiometry of the solution.The products of the reaction are limited to calcium oxalate dihydrate (weddellite), while no monohydrate (whewellite) or trihydrate (caoxite) oxalates were detected. The chemistry of the system was intentionally kept far from the stability field of the carbonates to avoid the co-precipitation of both calcium carbonate and oxalate and, accordingly, the competition between the two phases on the carbon capture process.The technological finalization of a carbon capture system exploiting this reaction will trustfully increase further the effectiveness of the method, pointing towards the zero CO2 emission. ReferencesAresta, M., Dibenedetto, A., 2007. Dalt. Trans. 0, 2975. https://doi.org/10.1039/b700658fBachu, S., 2008. Prog. Energy Combust. Sci. https://doi.org/10.1016/j.pecs.2007.10.001Baker, J.M., Ochsner, T.E., Venterea, R.T., Griffis, T.J., 2007. Agric. Ecosyst. Environ. https://doi.org/10.1016/j.agee.2006.05.014García-España, E., Gaviña, P., Latorre, J., Soriano, C., Verdejo, B., 2004. J. Am. Chem. Soc. 126, 5082–5083. https://doi.org/10.1021/ja039577hLively, R.P., Sharma, P., Mccool, B.A., Beaudry-Losique, J., Luo, D., Thomas, V.M., Realff, M., Chance, R.R., 2015. Biofuels, Bioprod. Biorefining 9, 72–81. https://doi.org/10.1002/bbb.1505Pastero, L., Curetti, N., Ortenzi, M.A., Schiavoni, M., Destefanis, E., Pavese, A., 2019. Sci. Total Environ. 666, 1232–1244. https://doi.org/10.1016/J.SCITOTENV.2019.02.114Rosa, G.M. da, Morais, M.G. de, Costa, J.A.V., 2018. Bioresour. Technol. 261, 206–212. https://doi.org/10.1016/j.biortech.2018.04.007Stenhouse, M., Arthur, R., Zhou, W., 2009. In: Energy Procedia. pp. 1895–1902. https://doi.org/10.1016/j.egypro.2009.01.247

In this contribution we present the first results for proposing an analytical protocol to analyze fly ashes (FA) with XRF.Fly ashes resulting from the incineration of municipal solid waste (MSW) should be considered as a hazardous material, mainly due to its potential high heavy metal content. Therefore, they have to be chemically fully characterized to facilitate primarily their safety storage and subsequently the recovery as second raw material resource. It’s worth noticing that fly ashes bulk chemistry (including volatile contents) depends on many types of variables [i.e.: geography; air pollution control devices (APCDs) and sampling sites], all related to the nature of the waste. On the basis of available data from different European waste-incineration plants, the bulk major elements contents are: Al If we consider fly ashes as “rock type” material, x-ray fluorescence (XRF) is used effectively for determining the major rock-forming elements. However, the lack of standard calibration for this material suggested us to adopt a different strategy of calibration, using the method of Standard Addition (SA) to determine SiO2 and Al2O3 having similar mass absorption coefficients (https://physics.nist.gov/PhysRefData/XrayMassCoef/tab3.html). The SA method was originally designed to determine trace elements contents by addition of comparative amounts of analytes. In order to keep the characteristics of bulk chemistry invariant, in this modified calibration procedure we prepared eleven pressed powders by adding several known aliquots of SiO2 and Al2O3 (“excipients”) to the same amount of unknown FA in the constant proportion of 10% and 90%, respectively.Plotting together the intensity values of the two analytes with the various percentages by weight of “excipients”, it was possible to generate calibration lines and acquired the percentage by weight of the two analytes in the unknown material. The Si and Al contents obtained by the calibration lines are 1.93 wt% and 1.64 wt%, respectively.These values are different from those (2.86 wt% and 1.40 wt% for Si and Al, respectively), obtained by measurements of pure FA with routine XRF standard calibrations for silicatic rocks (Franzini et al. 1975). More measurements are needed to evaluate the accuracy of the method, however, the results presented here are promising, and hint that XRF may be used efficiently to measure FA major element chemistry, by applying the modified standard addition calibration.References:Bodénan, F. and Deniard P. (2003). Chemosphere, 51; 335-347De Boom A. and Degrez M. (2012). Waste Management, 32; 1163-1170Franzini M., Leoni L. and Saitta M. (1975). Rend. S.I.M.P., 31: 365-378.

Treatments to reduce the leaching of contaminants (chloride, sulfate, heavy metals) into the environment from bottom ash (BA) are investigated, as a function of the ash&rsquo, s particle size (s). The aim is to make BA suitable for reuse as secondary raw material, in accordance with the legal requirements. Such treatments must be economically feasible and, possibly, have to use by-products of the plant (in this case, steam in excess from the turbine). For the sake of completeness and comparison, carbonation is performed on those BA particle size classes that are not positively responsive to steam washing. BA is partitioned into four different particle size classes (s &ge, 4.75, 4.75 &gt, s &ge, 2, 2 &gt, 1 and s &lt, 1 mm, corresponding to 36, 24, 13 and 27 wt%, respectively). In the case of s &ge, 2 mm (60 wt%), steam washing is effective in reducing to under the legal limits the leaching of chlorides, sulfate and heavy metals (Zn, Cu, Cd, Pb). It has been observed that steam washing causes both removal and dissolution of thin dust adherent to the BA&rsquo, s surface. BA with 2 &gt, 1 (~13 wt% of total BA) requires a combination of steam washing and carbonation to achieve a leaching below the legal limits. The finest BA fraction, s &lt, 1 mm (~27 wt% of total BA), is treated by carbonation, which reduces heavy metals leaching by 85%, but it fails to sufficiently curb chlorides and sulfates.

Herein is presented a rare example of salt/cocrystal polymorphism involving the adduct between ethionamide (ETH) and salicylic acid (SAL). Both the salt and cocrystal forms have the same stoichiometry and composition and are both stable at room temperature. The synthetic procedure was successfully optimized in order to selectively obtain both polymorphs. The two adducts' structures were thoroughly investigated by means of single-crystal X-ray diffraction, solid-state NMR spectroscopy, and density functional theory (DFT) calculations. From the solid-state NMR point of view, the combination of mono- and multinuclear experiments (1H MAS, 13C and 15N CPMAS, 1H-{14N} D-HMQC, 1H-14N PM-S-RESPDOR) provided undoubted spectroscopic evidence about the different positions of the hydrogen atom along the main N···H···O interaction. In particular, the 1H-14N PM-S-RESPDOR allowed N-H distance measurements through the 1H detected signal at a very high spinning speed (70 kHz), which remarkably agree with those derived by DFT optimized X-ray diffraction, even on a natural abundance real system. The thermodynamic relationship between the salt and the cocrystal was inquired from the experimental and computational points of view, enabling the characterization of the two polymorphs as enantiotropically related. The performances of the two forms in terms of dissolution rate are comparable to each other but significantly higher with respect to the pure ETH.

Nowadays, the production of constructional materials requires raw materials obtained through extractive activities that often imply different environmental impacts. In a perspective of a growing sensitivity towards a responsible use of natural resources the attention to materials coming from waste is focused. The waste from the municipal thermovalorization plants can be suitable for this applications, and after moderate and sustainable treatments, can find a role of raw material-second in the construction of works, reducing the need to find additional natural resources and related problems for disposal or storage. The present study aims to explore the possibility of promoting inertization (i.e. reducing the BA’s release in water of environmentally dangerous chemical species below the legal thresholds) of as large a fraction of BA as possible, using ashes from one of the municipal waste incineration plants of Northern Italy, and exploiting byproducts of the incineration cycle, i.e. the spared steam from turbines, which produce electricity, and carbon dioxide from combustion fumes. The treatments discussed are as a function of the particle size (s). BA are partitioned into three main classes, determined by previous studies s ≥ 4.75, 4.75 > s ≥ 1, s < 1 mm; %. The BA fraction with 4.75 > s ≥ 1 mm was further divided into two portions to optimize the steam washing process: 4.75 > s ≥ 2 mm and 2 > s ≥ 1 mm. BA with s > 4.75 mm are treated with steam washing only. In fact, although they do not contain high concentrations of heavy metals, they largely surpass the Italian legislation thresholds related to the occurrence of chlorides and sulfates. Steam is generally available from modern incineration plants in a considerable amount, and it is more effective than water in removing a variety of impurities/low-crystallinity fragments from the surface of coarse grains. Inertization of BA with 4.75 > s ≥ 1 is investigated by means of both steam washing and accelerated carbonation, to optimize the combination of these methods and expand as much as possible the s-range that requires steam washing only. As to the BA fraction with s < 1 mm, whose heavy metals content is likely larger than elsewhere, steam washing is of difficult application and therefore we resort to accelerated carbonation.