Publications by authors named "Nuria Ortuno"

Article Synopsis
  • Researchers have developed modified mesoporous zeolites that improve the diffusion of long-chain polymers, effectively tackling limitations in current plastic waste upcycling methods.
  • The new zeolite, M720, shows significantly lower degradation temperatures for common plastics, making the catalytic conversion process more efficient—reducing temperatures for items like plastic bottles and food packaging by as much as 146 °C.
  • This advancement enhances both the effectiveness and sustainability of converting plastic waste into valuable products while preserving the zeolite’s microstructure for consistent results.
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This study examines the presence of bisphenol A (BPA), S (BPS), F (BPF), and M (BPM) in various recycled plastics readily available on the market (LDPE, HDPE, PET, and PP), in light of European Food Safety Authority (EFSA) limits. Twenty samples of different origin are analyzed, cleaning treatments are applied, and the migration potential of these bisphenols into food is studied. BPM is absent in all samples, but a post-consumer recycled LDPE sample reveals high bisphenol concentrations, raising concerns, reaching 8540 ng/g, 370 ng/g, and 29 ng/g of BPA, BPS, and BPF, respectively.

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Residual biomass gasification is a promising route for the production of H-rich syngas. However, the simultaneous formation of pollutants such as light hydrocarbons (HCs), benzene, toluene and xylenes (BTEX), polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) during gasification must be controlled. As a result, this study evaluated the effect of temperature and catalytic reforming over a Rh-Pt/CeO-SiO catalyst during steam gasification of sugarcane residual biomass on syngas composition and pollutant removal.

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Dioxin-like polychlorinated biphenyls (DL-PCBs) are environmental pollutants that have been associated with impaired semen quality. However, research on the potential impact of paternal exposure to DL-PCBs and the risk of adverse pregnancy outcomes are limited. We examine the relationship between serum DL-PCB concentrations and IVF outcomes among 42 males seeking fertility treatment.

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Persistent organic pollutant inhibition in the combustion process of polyvinyl chloride (PVC) by prior addition of an inhibitor is currently being studied, reducing the emission of pollutants, and thus reducing the large amount of waste PVC destined for landfill. In this work, the use of sewage sludge (SS) as an alternative to chemical inhibitors to improve the quality emissions of the incineration of polyvinyl chloride waste (PVC e-waste) was studied and optimized. Different combustion runs were carried out at 850 °C in a laboratory tubular reactor, varying both the molar ratio R (0.

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In our lab, we have been studying the emissions of different pollutants during pyrolysis and combustion of wastes under different conditions for the last three decades. These studies have focused on the effect of temperature and presence of oxygen on the production of different pollutants. Waste decomposition has been studied in a horizontal laboratory scale reactor, but no estimate has been made of the actual emissions in a conventional thermal decomposition system.

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This study investigates the geometric and electronic properties of selected BFRs in their ground (S) and first singlet excited (S) states deploying methods of the density functional theory (DFT) and the time-dependent density functional theory (TDDFT). We estimate the effect of the S→ S transition on the elongations of the C-Br bond, identify the frontier molecular orbitals involved in the excitation process and compute partial atomic charges for the most photoreactive bromine atoms. The bromine atom attached to an ortho position in HBB (with regard to C-C bond; 2,2',4,4',6,6'-hexabromobiphenyl), TBBA (with respect to the hydroxyl group; 2,2',6,6'-tetrabromobisphenol A), HBDE and BTBPE (in reference to C-O linkage; 2,2',4,4',6,6'-hexabromodiphenylether and 1,2-bis(2,4,6-tribromophenoxy)ethane, respectively) bears the highest positive atomic charge.

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The inhibitory effect of thiourea (TUA), ammonium thiosulfate (TSA) and amidosulfonic acid (ASA) on the reactivity of fly ash air was investigated using a thermobalance at different heating rates (5, 10 and 20 K min). A model fly ash (activated carbon + 50 wt% CuCl·2HO, pyrolyzed at 700 °C and washed) was used as carbonaceous material. Adding CuCl·2HO to the activated carbon led to an increased rate of decomposition with the air's oxygen.

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Combustion and pyrolysis runs at 850°C were carried out in a laboratory scale horizontal reactor with different materials combining biomass and waste electrical and electronic equipment (WEEE). Analyses are presented of the carbon oxides, light hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), polychlorinated benzenes (ClBzs), polychlorinated phenols (ClPhs), polybrominated phenols (BrPhs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Results showed that gas emissions were mainly composed of CO and CO; the high level of CO found in the pyrolytic runs was easily transformed into CO by reaction with oxygen.

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Four different types of fuel blends containing demolition and construction wood and household waste were combusted in a small-scale experimental set-up to study the effect of fuel composition on the emissions of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), chlorobenzenes (PCBzs), chlorophenols (PCPhs) and polycyclic aromatic hydrocarbons (PAHs). Two woody materials, commercial stemwood (ST) and demolition and construction wood (DC) were selected because of the differences in their persistent organic pollutants (POPs), ash and metals content. For household waste, we used a municipal solid waste (MSW) and a refuse-derived fuel (RDF) from MSW with 5-20 wt% and up to 5 wt% food waste content respectively.

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Degradation of brominated flame retardants present in printed circuit boards (PCBs) was tested using subcritical water in a high pressure reactor. Debromination experiments were carried out in a batch stirred reactor at three different temperatures (225 °C, 250 °C and 275 °C) keeping a solid to liquid (S/L) ratio of PCB:water = 1:5 during 180 min. Results indicated that debromination efficiency was increased with temperature (18.

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The relationship between dioxin-like polychlorinated biphenyl (DL-PCB) levels in serum and semen parameters were investigated. Our case-control included two groups of patients. Total concentrations of PCBs were significantly higher in the low semen quality (n=24) than in the normal semen quality (n=26) group.

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The present work has been carried out to verify the feasibility of thermal valorization of an automobile shredder residue (ASR). With this aim, the thermal decomposition of this waste has been studied in a laboratory scale reactor, analyzing the pollutants emitted under different operating conditions. The emission factors of carbon oxides, light hydrocarbons, PAHs, PCPhs, PCBzs, PBPhs, PCDD/Fs, dioxin-like PCBs and PBDD/Fs were determined at two temperatures, 600 and 850°C, and under different oxygen ratios ranging from 0 (pure pyrolysis) to 1.

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The aim of the present work was to assess the emission of different persistent organic pollutants from a cement plant over a period of one year, under normal operational conditions. Thus, a long-term sampling device was installed in the clinker kiln stack of the cement plant. The factory uses petroleum coke as primary fuel, but also alternative fuels such as solid recovered fuel (SRF), automotive shredder residue (ASR), sewage sludge, waste tires, and meat and bone meal (MBM) wastes, with an energy substitution level of about 40%.

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The 14th International Congress on Combustion By-Products and Their Health Effects was held in Umeå, Sweden from June 14th to 17th, 2015. The Congress, mainly sponsored by the National Institute of Environmental Health Sciences Superfund Research Program and the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning, focused on the "Origin, fate and health effects of combustion-related air pollutants in the coming era of bio-based energy sources". The international delegates included academic and government researchers, engineers, scientists, policymakers and representatives of industrial partners.

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An accurate and easy method for the extraction, cleanup, and HRGC-HRMS analysis of dioxin-like PCBs (DL-PCBs) in low-volume serum samples (1 mL) was developed. Serum samples were extracted several times using n-hexane and purified by acid washing. Recovery rates of labeled congeners ranged from 70 to 110% and the limits of detection were below 1 pg/g on lipid basis.

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The emissions of polybrominated diphenyl ethers (PBDEs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) and their chlorinated analogues (PCDD/Fs) during the thermal treatment of a high impact polystyrene (HIPS) TV casing were investigated. The halogenated compounds were analyzed in the original material and in the gases emitted during its treatment at temperatures between 50 °C and 250 °C. DecaBDE was the primary PBDE in the TV casing, which also contained high levels of PBDFs (ppm range).

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The constant increase in the production of electronic devices implies the need for an appropriate management of a growing number of waste electrical and electronic equipment. Thermal treatments represent an interesting alternative to recycle this kind of waste, but particular attention has to be paid to the potential emissions of toxic by-products. In this study, the emissions from thermal degradation of printed circuit boards (with and without metals) have been studied using a laboratory scale reactor, under oxidizing and inert atmosphere at 600 and 850 °C.

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On the basis of laboratory experiments with model mixtures (active carbon+CuBr2 at different loads), this work studies the formation of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) by de novo synthesis. For the different samples, the temperature of the maximum carbon oxidation rate was determined by thermogravimetric analysis, and a kinetic model was proposed for the degradation of the materials in an oxidizing atmosphere (synthetic air). The effect of the addition of different amounts of CuBr2 was studied, finding that its presence accelerates the degradation of the carbonaceous structure in the presence of oxygen.

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Tetrabromobisphenol A (TBBPA) is the most widely used brominated flame retardant worldwide. A detailed examination of the degradation products emitted during thermal decomposition of TBBPA is presented in the study. Runs were performed in a laboratory furnace at different temperatures (650 and 800 °C) and in different atmospheres (nitrogen and air).

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Combustion runs at 700 °C in a horizontal laboratory furnace were carried out on two different electric wires (PVC and halogen-free wire). Tests were performed in the presence and in the absence of the metal conductor of the wires. The analyses of the polycyclic aromatic hydrocarbons (PAHs), chlorobenzenes (CBzs), chlorophenols (CPhs), mono- to octa-chlorodibenzo-p-dioxin and dibenzofurans (PCDD/Fs), and dioxin-like PCBs are shown.

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