European Union legislation overview about used vegetable oils recycling: the spanish and italian case studies

The employment of used vegetable oils (UVOs) as raw materials in key sectors as energy production or bio-lubricant synthesis represents one of the most relevant priorities in the European Union (EU) normative context. In many countries, the development of new production processes based on the circular economy model, as well as the definition of future energy and production targets, involve the utilization of wastes as raw material. In this context, the main currently applied EU regulations are presented and discussed. As in the EU, the general legislative process consists of the definition in each State Member of specific legislation, which transposes the EU indications. Two relevant countries are herein considered: Italy and Spain. Through the analysis of the conditions required in both countries for UVOs’ collection, disposal, storage, and recycling, a wide panorama of the current situation is provided

Toxicological assessment of nanocrystalline metal alloys with potential applications in the aeronautical field

The development of new candidate alloys with outstanding characteristics for their use in the aeronautical field is one of the main priorities for the sector. In this context, nanocrystaline (nc) alloys are considered relevant materials due to their special features, such as their exceptional physical and mechanical properties. However, another important point that needs to be considered with newly developed alloys is the potential toxicological impact that these materials may have in humans and other living organisms. The aim of this work was to perform a preliminary toxicological evaluation of three nc metal alloys (WCu, WAl and TiAl) in powder form produced by mechanical alloying, applying different in vitro assays, including a mix of W-Cu powders with standard grain size in the experiments to stablish comparisons. The effects of the direct exposure to powder suspensions and/or to their derived leachates were analysed in three model organisms representative of human and environmental exposures (the adenocarcinomic human alveolar basal epithelial cell line A549, the yeast Saccharomyces cerevisiae and the Gram negative bacterium Vibrio fischeri). Altogether, the results obtained provide new insights about the potential harmful effects of the selected nc alloys, showing that, from a toxicological perspective, nc TiAl is the safest candidate in the model organisms and conditions tested.EU Horizon 2020 projects ICARUS (H2020-FETOPEN-2014-2015-RIA, grant agreement N° 713514) and ICARUS-INAS (FETOPEN-03-2018-2019-2020, Grant agreement N° 946174)

In vitro safety evaluation of rare earth-lean alloys for permanent magnets manufacturing

Due to their exceptional physico-chemical and magnetic characteristics, rare earth (RE) permanent magnets are applied in multiple critical technologies. However, several environmental and economic difficulties arising from obtaining RE elements have prompted the search of alternatives with acceptable magnetic properties but containing a lower percentage of these elements in their composition. The aim of this work was to perform a preliminary toxicological evaluation of three forms of newly developed RE-lean alloys (one NdFeTi and two NdFeSi alloys) applying different in vitro assays, using as a benchmark a commercial NdFeB alloy. Thus, the effects of the direct exposure to powder suspensions and to their derived leachates were analysed in two model organisms (the A549 human cell line and the yeast Saccharomyces cerevisiae) applying both viability and oxidative stress assays. Moreover, the impact of the alloy leachates on the bioluminescence of Vibrio fischeri was also investigated. The obtained data showed that only the direct interaction of the alloys particulates with the applied organisms resulted in harmful effects, having all the alloys a comparable toxicological potential to that presented by the reference material in the conditions tested. Altogether, this study provides new insights about the safety of NdFeTi and NdFeSi alloys.EU Horizon 2020 NOVAMAG project (NMBP 23-2015, Grant Agreement No. 686056) and from the Junta de Castilla y León and the European Social Fund-Youth European Initiative Grant UBU-15-A

Carbon nanomaterials with Thymol + Menthol Type V natural deep eutectic solvent: From surface properties to nano-Venturi effect through nanopores

A theoretical study using Density Functional Theory and classical Molecular Dynamics simulations for the study of carbon nanomaterials in archetypical Menthol + Thymol Type V Natural Deep Eutectic Solvent is reported. The nanoscopic structure of the representative nanofluid is analyzed considering confinement, adsorption and solvation effects, as well as consequences on diffusion properties through nano pores. Different types of nanomaterials were considered such as fullerenes, nanotubes, graphene and nanopores. The study of nanoscopic properties allowed to analyze the response of the solvent to the presence of the nanomaterials, taking into account solvent rearrangement and confinement in nanocavities and surfaces. This response shows liquid structure and mobility consequences, with a sort of nano-Venturi effect among them. The reported results provide for the first time a characterization of this type of natural solvents as a sustainable platform for the development of carbon – nanomaterials-based technologies.This work was funded by Junta de Castilla y León (Spain, project NANOCOMP - BU058P20), European Union H2020 Program (H2020-NMBP-TO-IND-2020-twostage-DIAGONAL-GA- 953152) and Ministerio de Ciencia, Innovación y Universidades (Spain, project RTI2018-101987-B-I00). We also acknowledge SCAYLE (Supercomputación Castilla y León, Spain) for providing supercomputing facilities. The statements made herein are solely the responsibility of the authors

Sustainability of phytoremediation: Post-harvest stratagems and economic opportunities for the produced metals contaminated biomass

Heavy metals (HMs) are indestructible and non-biodegradable. Phytoremediation presents an opportunity to transfer HMs from environmental matrices into plants, making it easy to translocate from one place to another. The ornate features of HMs’ phytoremediation are biophilia and carbon neutrality, compared to the physical and chemical remediation methods. Some recent studies related to LCA also support that phytoremediation is technically more sustainable than competing technologies. However, one major post-application challenge associated with HMs phytoremediation is properly managing HMs contaminated biomass generated. Such a yield presents the problem of reintroducing HMs into the environment due to natural decomposition and release of plant sap from the harvested biomass. The transportation of high yields can also make phytoremediation economically inviable. This review presents the design of a sustainable phytoremediation strategy using an everevolving life cycle assessment tool. This review also discusses possible post-phytoremediation biomass management strategies for the HMs contaminated biomass management. These strategies include composting, leachate compaction, gasification, pyrolysis, torrefaction, and metal recovery. Further, the commercial outlook for properly utilizing HMs contaminated biomass was presented.Authors apologize to all authors whose research has supported this area of interest, and their relevant findings were left out during the preparation of this review. Funding sources: This work was financed by the GREENER project of the European Union’s Horizon 2020 research and innovation program (Grant Agreement No. 826312). It has also received funds from Board of Education of Junta de Castilla y Leon ´ and the European Social Fund

Comparative Life Cycle Assessment of Green Sand Casting and Low Pressure Die Casting for the production of self-cleaning AlMg3-TiO2 Metal Matrix Composite

The growth in the use of novel materials, as it is the case of the Metal Matrix Composites (MMCs), is producing a positive impact in production processes, allowing to obtain final products with improved functionalities, such as an increase of the strength-to-weight ratio, or enhancement of the mechanical properties of the material, minimizing as well the environmental impacts and production costs without compromising the required technical properties. To determine and compare the environmental impact of different processes employing these materials, this paper provides a comparative analysis of the Life Cycle Assessment (LCA), under ISO 14040:2006 framework and European ILCD guidelines, of two different manufacturing technologies, Green Sand Casting (GSC) and Low Pressure Die Casting (LPDC), for the particular case of a self-cleaning doorknob, produced by an aluminium alloy reinforced with hard TiO2 nanoparticles, that confers special characteristics to the composite, such as an increase of the hardness value and tensile strength, a high wear resistance, a good chemical stability, and antibacterial properties. The results show a slight difference between both technologies in terms of kg CO2 eq. emitted, with just a 3,16 % variation, where GSC emissions are 13,098 kg, whereas 12,684 kg are released from LPDC. In addition, an economic analysis was performed, showing a 17 % cost reduction in case of LPDC. This study presents for the first time a comparative Life Cycle Assessment of GSC and LPDC, when employing new nanocomposite materials, contributing with novel datasets and meaningful insights to improve the state of the art in the field, serving as well as a support for manufacturers in decision making process involving the use of these technologies.This research has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant Agreement No. 826312) in the context of the LightMe project. It has also received funds from Board of Education of Junta de Castilla y León and the European Social Fund (EDU/1508/2020). The authors want to acknowledge the support of ÖGI (Österreichisches Gießerei-Institut) for the data about processes

Additivation of MoS2 nanosheets to synthetic poly-alpha-olefins base oils: A theoretical study of nanolubrication

A theoretical study considering Density Functional Theory and classical Molecular Dynamics simulations is reported on the study of the behavior of model poly-α-olefins base oils interacting with 2D MoS2 monolayers. 2D materials offer a promising route to enhance anti wear and friction reduction. Among them, MoS2 show a set of specially favorable properties. The objective of the present work is to develop a nanoscopic characterization to show the roots of the use of 2D MoS2 monolayers as additives that reduce friction and wear with respect to plain lubricants. Three different types of hydrocarbons are considered, including the most relevant features of these oils: linear, star-like and branched compounds. The reported results show a large affinity of the three compounds for the monolayer surface, leading to very efficient adsorption guided by van der Waals interactions as well as by certain charge transfer toward the hydrocarbon. The development of adsorbed layers on the surface leads to changes in the base oil properties although being concentrated in a region close to the monolayer, with lower effects at larger distances. The presence of hydrocarbons with very different geometries hinders highly ordered molecular packing beyond the layer in direct contact with the surface. Nevertheless, the rearrangements on top of the MoS2 surface will lead to large changes in the base oil behavior for lubrication purposes, enhancing tribological and anti-wear properties of MoS2 nanosheet additivated poly-α-olefins base oils.European Union (H2020-MSCA-ITN-2016-SOLUTION-GA-721642 project

On the behavior of quercetin + organic solvent solutions and their role for C60 fullerene solubilization

The nature of flavonoids in polar organic solvents solutions is studied using classical molecular dynamics simulations considering quercetin as an archetypical flavonoid and acetone, dimethylformamide and dimethyl sulfoxide as representatives of solvents with different polarity. The solvation, intermolecular forces (hydrogen bonding) and interactions of the flavonoid with the solvents are analyzed. Likewise, the role of quercetin on changing the solvent properties and the possibility of acting as a solubility enhancer for fullerenes (C60) are studied by considering the properties of C60 fullerene in quercetin plus polar solvents solutions. The reported results provide information on the nature of the considered complex liquid mixtures and analyze the possibility of using flavonoids as natural, non-toxic, modifiers of traditional polar organic solvents and to improve the solubility of complex solutes such as fullerene nanoparticles.Junta de Castilla y Leon (Spain, project NANOCOMP - BU058P20) and Ministerio de Ciencia, Innovación y Universidades (Spain, project RTI2018-101987-B-I00). We also acknowledge SCAYLE (Supercomputación Castilla y León, Spain) for providing supercomputing facilities

Low toxicological impact of commercial pristine multi-walled carbon nanotubes on the yeast saccharomyces cerevisiae

Carbon nanotubes (CNTs) have attracted the attention of academy and industry due to their potential applications, being currently produced and commercialized at a mass scale, but their possible impact on different biological systems remains unclear. In the present work, an assessment to understand the toxicity of commercial pristine multi-walled carbon nanotubes (MWCNTs) on the unicellular fungal model Saccharomyces cerevisiae is presented. Firstly, the nanomaterial was physico-chemically characterized, to obtain insights concerning its morphological features and elemental composition. Afterwards, a toxicology assessment was carried out, where it could be observed that cell proliferation was negatively affected only in the presence of 800 mg L−1 for 24 h, while oxidative stress was induced at a lower concentration (160 mg L−1 ) after a short exposure period (2 h). Finally, to identify possible toxicity pathways induced by the selected MWCNTs, the transcriptome of S. cerevisiae exposed to 160 and 800 mg L−1, for two hours, was studied. In contrast to a previous study, reporting massive transcriptional changes when yeast cells were exposed to graphene nanoplatelets in the same exposure conditions, only a small number of genes (130) showed significant transcriptional changes in the presence of MWCNTs, in the higher concentration tested (800 mg L−1 ), and most of them were found to be downregulated, indicating a limited biological response of the yeast cells exposed to the selected pristine commercial CNTs

Comparative Life Cycle Assessment and Cost Analysis of the Production of Ti6Al4V-TiC Metal–Matrix Composite Powder by High-Energy Ball Milling and Ti6Al4V Powder by Gas Atomization

Environmental awareness and the necessary reduction in costs in industrial processes has facilitated the development of novel techniques such as Additive Manufacturing, decreasing the amount of raw materials and energy needed. The longing for improved materials with different and enhanced properties has resulted in research efforts in the Metal Matrix Composites field. These two novelties combined minimise environmental impacts and costs without compromising technical properties. Two technologies can feed Additive Manufacturing techniques with metallic powder: Gas Atomization and High Energy Ball Milling. This study provides a comparative Life Cycle Assessment of these technologies to produce one kilogram of metallic powder for the Directed Energy Deposition technique: a Ti6Al4V alloy, and a Ti6Al4V-TiC Metal–Matrix Composite, respectively. The LCA methodology is according to ISO 14040:2006, and large amounts of information on the use of raw materials, energy consumption, and environmental impacts is provided. Different impact categories following the Environmental Footprint methodology were analysed, showing a big difference between both technologies, with an 87.8% reduction of kg CO2 eq. emitted by High Energy Ball Milling in comparison with Gas Atomization. In addition, an economic analysis was performed, addressing the viability perspective and decision making and showing a 17.2% cost reduction in the conventional process