Evaluating by LCA the environmental impact savings related to the use of waste incineration bottom ash in porcelain tiles manufacturing: The role of metals recovery

The implementation of circular economy concepts in industrial manufacturing is being promoted in many Countries, in particular by the EU. The evaluation of the economic and environmental savings related to the decrease of the amounts of waste sent to final disposal and also of the impacts of the extraction of raw materials, are of particular relevance to companies. In particular, Life Cycle Assessment (LCA) and footprint analysis are being increasingly applied with the aim of attaining Environmental Product Declarations (EPDs) to prove to potential customers how “greener” the products achieved employing circular routes are compared to those attained via traditional linear processes. It should be noted however, that the environmental advantages that can be achieved can vary significantly according to the specific characteristics of the system in question, such as the current strategies applied for managing the waste, the types and amounts of raw materials that are replaced and the distance of supply of each type of material (both for the waste and raw materials). A type of waste material that is currently being increasingly used outside of landfills is waste incineration bottom ash. This material is employed as aggregates or sand substitutes in concrete or asphalt mixtures, as aggregates in unbound applications, or as raw material in cement or recently also ceramics manufacturing. In any case, the bottom ash is first treated to recover ferrous and non-ferrous metals and may undergo different treatments such as particle size separation, crushing, washing, natural weathering and/or binder addition, in view of the intended application. In this study, we focused on the relevance of some of the input parameters and assumptions on the environmental impacts resulting for a cradle to gate LCA case study concerning a manufacturing process employing waste incineration bottom ash. Specifically, data from a company in Central Italy that has started a production line of porcelain stoneware tiles using waste incineration bottom ash in partial replacement of feldspar sands was employed to evaluate the environmental impacts related to the manufacturing of the new product, comparing them to those of the same type of tiles produced using only quarried material. From the comparison of the environmental performances related to the production of the two types of products (stoneware tiles with and without bottom ash) assessed employing the EPD 2018 method and Simapro 9.1.1 software, the production of the tile containing the bottom ash compared to that obtained by the traditional process would in particular involve a significant decrease of the following impacts: mineral consumption and eutrophication (70%), photochemical smog and acidification (40-45%) and climate change (25%). In particular, the results showed that the reduction of the impacts is not so much linked to the impacts avoided for the extraction and transport of feldspar replaced by bottom ash, as to the recovery of ferrous and non-ferrous metals from the bottom ash implemented in the tiles manufacturing plant. It is evident hence that the results are strongly dependent on the assumptions made regarding the amounts of iron and aluminum that can be recovered and the processes assumed for their recovery. In particular, the substitution of primary steel and aluminum production were considered, although the impacts related to secondary steel and aluminum production were accounted for and substitution ratios lower than 1 were considered. It should be highlighted that for the analyzed case study it was considered that the bottom ash would be treated for metal recovery at the plant and would be diverted from landfills. If instead pre-treated bottom ash intended for reuse as aggregates were employed in the tile production process, the potential environmental benefits that could be achieved would be significantly lower. At the Conference the results of the study, and in particular the effects of the assumptions made on ferrous and non-ferrous metals recovery, with regard to amounts, quality and utilization/substitution scenarios, as well as of the management options for the bottom ash and transport distances, will be assessed in terms of their overall effect on the environmental impact savings of the examined circular economy process

Determining wood chip size: image analysis and clustering methods

One of the standard methods for the determination of the size distribution of wood chips is the oscillating screen method (EN 15149- 1:2010). Recent literature demonstrated how image analysis could return highly accurate measure of the dimensions defined for each individual particle, and could promote a new method depending on the geometrical shape to determine the chip size in a more accurate way. A sample of wood chips (8 litres) was sieved through horizontally oscillating sieves, using five different screen hole diameters (3.15, 8, 16, 45, 63 mm); the wood chips were sorted in decreasing size classes and the mass of all fractions was used to determine the size distribution of the particles. Since the chip shape and size influence the sieving results, Wang’s theory, which concerns the geometric forms, was considered. A cluster analysis on the shape descriptors (Fourier descriptors) and size descriptors (area, perimeter, Feret diameters, eccentricity) was applied to observe the chips distribution. The UPGMA algorithm was applied on Euclidean distance. The obtained dendrogram shows a group separation according with the original three sieving fractions. A comparison has been made between the traditional sieve and clustering results. This preliminary result shows how the image analysis-based method has a high potential for the characterization of wood chip size distribution and could be further investigated. Moreover, this method could be implemented in an online detection machine for chips size characterization. An improvement of the results is expected by using supervised multivariate methods that utilize known class memberships. The main objective of the future activities will be to shift the analysis from a 2-dimensional method to a 3- dimensional acquisition process

UHMWPE for arthroplasty: past or future?

Wear debris related osteolysis is recognised as being the main cause of failure in joint replacements based on UHMWPE inserts. However, many solutions and “new” polyethylenes have been suggested in order to address this issue. This review discusses “historical” issues associated with UHMWPE, such as oxidation, sterilization method and storage, as well as “new” topics, such as crosslinking and stabilization. The final aim is to aid orthopaedic surgeons in their selection of polyethylene inserts and in the information given to the patients. The main problem for the polymer is degradative oxidation, which is caused by the combination of the irradiation used for sterilization and oxygen, and which leads to a decrease in wear resistance and mechanical properties. Irradiation and packaging in the absence of oxygen can only reduce the oxidation, while sterilization with gas (EtO or gas plasma) is the only method that effectively eliminates it. Manufacturing processes are of great relevance to the clinical duration and must be considered by surgeons. Crosslinked polyethylene has been developed for joint inserts due to its superior wear resistance compared to conventional UHMWPE; to prevent the oxidation, crosslinked polyethylene requires post-irradiation thermal treatment, which reduces its mechanical properties and which depends on the producer. Several good clinical results from the use of crosslinked acetabular cups have reported at mid-term, while early results for knee replacements are also encouraging. Recently, the use of the antioxidant vitamin E (alpha-tocopherol) has been introduced for joint prostheses in order to prevent the oxidation of both crosslinked and noncrosslinked UHMWPE

Noises investigations and image denoising in femtosecond stimulated Raman scattering microscopy

In the literature of SRS microscopy, the hardware characterization usually remains separate from the image processing. In this article, we consider both these aspects and statistical properties analysis of image noise, which plays the vital role of joining links between them. Firstly, we perform hardware characterization by systematic measurements of noise sources, demonstrating that our in-house built microscope is shot noise limited. Secondly, we analyze the statistical properties of the overall image noise, and we prove that the noise distribution can be dependent on image direction, whose origin is the use of a lock-in time constant longer than pixel dwell time. Finally, we compare the performances of two widespread general algorithms, that is, singular value decomposition and discrete wavelet transform, with a method, that is, singular spectrum analysis (SSA), which has been adapted for stimulated Raman scattering images. In order to validate our algorithms, in our investigations lipids droplets have been used and we demonstrate that the adapted SSA method provides an improvement in image denoising

Micro-bore Column Fast Gas Chromatography-Mass Spectrometry in Essential Oil Analysis:

The present research is focused on the use of micro-bore column fast gas chromatography in combination with rapid-scanning quadrupole mass spectrometry for mediumly-complex essential oil analysis. A basil essential oil sample was initially subjected to conventional GC-MS (analysis time: 25 min) under optimum analytical conditions. Peak identification was carried by using a dual-filtered MS library search procedure: the first filter deleted "hits" with a less than 90% spectral similarity, while the second filter eliminated matches with a linear retention index (LRI) outside a pre-defined LRI window. The same essential oil sample was analyzed under optimized fast GC-MS conditions by using a micro-bore column, with the same aforementioned MS library search process (analysis time: 5.3 min). Resolution was altogether similar in both applications, with the same number of compounds reliably-identified, namely fifty-nine. The experiment demonstrated the usefulness of the rapid GC approach in this type of experiment

Longitudinal Measurement of Serum Vascular Endothelial Growth Factor in Patients with Chronic Obstructive Pulmonary Disease

Impaired vascular endothelial growth factor (VEGF) signaling causes emphysema in animal models. In chronic obstructive pulmonary disease (COPD) patients, alterations in VEGF tissue expression have been observed. We hypothesize that circulating VEGF may be a biomarker to phenotype COPD patients.; The aim of this study was to investigate VEGF serum levels in stable and exacerbated COPD.; VEGF serum levels as well as parameters of short- and long-term outcome were assessed and analyzed in two COPD cohorts [PROMISE, n = 117; ProCOLD (PC), n = 191].; VEGF serum levels at stable COPD were neither related to forced expiratory volume in 1 s nor to the Modified Medical Research Council dyspnea score, 6-min walking distance or BODE index. There was no association between single VEGF levels and COPD exacerbation frequency or mortality at 1 and 2 years of follow-up. In PC an increase in VEGF over time (ΔVEGF) was associated with the exacerbation frequency as well as the 1- and 2-year hospitalization rate (p = 0.046, 0.009 and 0.006, respectively). Furthermore, in PC ΔVEGF was associated with 1- and 2-year survival (p = 0.009 and 0.041, respectively).; Single serum VEGF levels, at stable and exacerbated COPD, were not associated with clinically significant outcomes in COPD. Conversely, the VEGF course seems related to COPD prognosis