42 research outputs found
The Use of a Simplified Carbon Footprint Tool for Organic Waste Managers: Pros and Cons
Abstract: Given that the pressure of climate change action on companies is increasing, it is recom-
mended to measure the improvement of mitigation activities in terms of GHG emissions. This paper
aims to highlight the still-open aspects that characterise simplified GHG accounting tools, starting
from the outcomes of a case study. This study was performed using a simplified Italian software
for the CO2 eq accounting of composting and anaerobic digestion, two mitigation activities that
contribute an important share of global GHG emissions reduction. The tool is based on the life-cycle
thinking approach. It has been applied to an Italian company that treats the organic fraction of
municipal solid waste. The tool analysis has made it possible to stress several issues that are currently
the object of debate in the literature, for example, the trade-off between the flexibility of the software
and its user friendliness or the multifunctionality issues and their different interpretations. However,
focusing on just one impact category, i.e., climate change, may lead to an incomplete picture of the
overall environmental performance of the process analysed. Therefore, this tool could be improved
by including other impact categories, such as eutrophication and acidification, which may be affected
by the studied activities
Analyses of Methanogenic Population as Key Indicator for Anaerobic Digestion: A Case-Study in the Organic Fraction of Municipal Solid Waste Treatment
Purpose
The anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) is a treatment biologically optimizable. The analysis of the microbial balance within the digester allows not only to describe and improve the efficiency of the system but also to foresee potential variations after biochemical interventions. This work aims to highlight methanogenic population variations in two similar parallel digesters to identify bio-indicators for digestion performance after the inclusion of an additive.
Methods
The analysed industrial case study involved the two parallel, pilot-scale, bio-digesters of ACEA Pinerolese Industriale. They had analogous design and fed by the same OFMSW except for an additive inclusion. The analyses by qRT-PCR, on both bio-digesters, have been performed to determine an impact of the additive on the growth and metabolic activity of total methanogens, Methanosarcina spp., Methanocorpuscolum spp., and Methanospirillus spp.
Results
Collected data showed that the addition of biopolymers extracted from compost produced both total methanogens and Methanosarcina decrease (7.67 vs. 7.48 and 6.05 vs. 5.69 Log gene copies/mL sludge respectively, T-test p < 0.01) affecting slightly the methane yield (-8%). Methanosarcina was the highest expressed methanogen; however, the results suggested the involvement of a highly complex and heterogeneous methanogen community.
Conclusions
Total methanogens and active Methanosarcina modulations are able to highlight major bio-methane production even if their shift is slight. Globally only 3–4% of the present and 12–13% of the active methanogens were described. However, biological approach can supply a proxy of production performance of the digester also concerning the feeding peculiarities
Periodontal disease treatment in dogs: comparison of the effectiveness of cavitator, curettage and dental polishing
El objetivo del estudio fue comparar la efectividad de los instrumentos utilizados más frecuentemente en medicina veterinaria para la limpieza de la superficie radicular. Se utilizaron 28 raíces dentales de perro involucradas en enfermedad periodontal severa y con un mínimo de 3 mm de retracción gingival. Las raíces fueron divididas en 4 grupos (7 por grupo), aplicándole a cada una de ellas un tratamiento distinto: limpieza con cavitador ultrasónico, curetaje, ambos métodos con y sin pulido de la superficie tratada. Se observaron con el MEB, tomando 4 microfotografías de 2 zonas distintas: coronaria y apical, a 100 y 500X (n=112 fotos). Se realizó una clasificación de las fotografías según una modificación del índice de cálculo remanente y el índice de pérdida de sustancia dental. Los resultados obtenidos, fueron procesados estadísticamente a través del test de Kruskal-Wallis’ para establecer si existían diferencias entre los grupos y luego por una comparación entre medias. El ultrasonido con posterior pulido demostró ser el tratamiento más eficiente. A pesar de producir una superficie con mayor pérdida dental que los otros métodos, ésta es despreciable y la cantidad de cálculo remanente es mínima.The aim of the study was to compare the effectiveness of the instruments most commonly used in veterinary medicine for cleaning the root surface. 28 dog teeth roots involved in severe periodontal disease and with a minimum of 3 mm gingival retraction were used. The roots were divided into 4 equal groups, applying to each a different cleaning treatment: ultrasonic scaler and curettage methods, both with and without polishing the treated surface. They were observed with SEM taking 4 micrographs of 2 distinct areas: coronary and apical, at 100 and 500X (n=112 pictures). Pictures were classified according to a modification of the remaining calculus and the loss of tooth substance index. The obtained results were statistically processed through the Kruskal-Wallis’ to establish whether there were differences among the groups and then by a comparison among means. Polishing after ultrasonic scaler cleaning method was the most efficient treatment. Despite producing more tooth loss than the other methods, this is minimum and the remaining amount of calculus is very low.Sociedad de Ciencias Morfológicas de La Plat
Dog dental enamel ultramorphology: analysis by scanning electron microscope. Preliminary report
El esmalte de los mamíferos está constituido en un 90% por cristales de hidroxiapatita formando “prismas” y la sustancia interprismática que los rodea. Los prismas varían su forma según la especie y se organizan en algunos casos en forma paralela (Bandas de Hunter-Schreger) y, en otras, de manera entrecruzada. En el perro existe escasa información al respecto, por lo que el objetivo de este estudio fue determinar la ultramorfología del esmalte en el perro mediante microscopía electrónica de barrido. Se seccionaron dientes permanentes sanos (n=24) con disco de diamante, se les grabó la superficie seccionada con ácido fosfórico y se procesaron para ser observados con el MEB. Se midió el espesor de los prismas en diferentes sitios del esmalte. Los prismas presentaron forma hexagonal y un espesor medio de 4,4 μm. Se encontraron sectores con bandas de Hunter-Schreger y sectores de prismas entrecruzados. Se concluye que el espesor de los prismas del esmalte del perro no varía según tipo de diente ni sector de la corona, exceptuando en las cúspides donde fue más angosto. La organización prismática observada fue similar a la informada en estudios previos del esmalte del perro.Mammals´ enamel is constituted in a 90% by hydroxyapatite crystals forming "prisms" and the interprismatic substance that surrounds them.
Prisms present different shape according to the species. In some regions they are organized in parallel (Hunter-Schreger bands), and in others in a crisscross way. There is little information regarding the dog, so the aim of this study was to determine the ultramorphology of dog enamel by scanning electron microscopy (SEM). A total of 24 permanent healthy dog teeth were selected. They were cut with a diamond disc and the cut surface was etched with phosphoric acid. The teeth were processed to be studied with the SEM, and the prisms thickness was measured at different sites of the enamel. Dog prisms presented hexagonal shape, and an average thickness of 4,4 μm. Regions with Hunter-Schreger bands, and regions with cross prisms were found. In conclusion, prisms thickness of dog enamel does not vary according to the type of tooth or sector of the crown, except in the cusps where it is narrower. Prismatic organization was similar to that reported in previous dog enamel studies.Sociedad de Ciencias Morfológicas de La Plat
Periodontal disease treatment in dogs: comparison of the effectiveness of cavitator, curettage and dental polishing
El objetivo del estudio fue comparar la efectividad de los instrumentos utilizados más frecuentemente en medicina veterinaria para la limpieza de la superficie radicular. Se utilizaron 28 raíces dentales de perro involucradas en enfermedad periodontal severa y con un mínimo de 3 mm de retracción gingival. Las raíces fueron divididas en 4 grupos (7 por grupo), aplicándole a cada una de ellas un tratamiento distinto: limpieza con cavitador ultrasónico, curetaje, ambos métodos con y sin pulido de la superficie tratada. Se observaron con el MEB, tomando 4 microfotografías de 2 zonas distintas: coronaria y apical, a 100 y 500X (n=112 fotos). Se realizó una clasificación de las fotografías según una modificación del índice de cálculo remanente y el índice de pérdida de sustancia dental. Los resultados obtenidos, fueron procesados estadísticamente a través del test de Kruskal-Wallis’ para establecer si existían diferencias entre los grupos y luego por una comparación entre medias. El ultrasonido con posterior pulido demostró ser el tratamiento más eficiente. A pesar de producir una superficie con mayor pérdida dental que los otros métodos, ésta es despreciable y la cantidad de cálculo remanente es mínima.The aim of the study was to compare the effectiveness of the instruments most commonly used in veterinary medicine for cleaning the root surface. 28 dog teeth roots involved in severe periodontal disease and with a minimum of 3 mm gingival retraction were used. The roots were divided into 4 equal groups, applying to each a different cleaning treatment: ultrasonic scaler and curettage methods, both with and without polishing the treated surface. They were observed with SEM taking 4 micrographs of 2 distinct areas: coronary and apical, at 100 and 500X (n=112 pictures). Pictures were classified according to a modification of the remaining calculus and the loss of tooth substance index. The obtained results were statistically processed through the Kruskal-Wallis’ to establish whether there were differences among the groups and then by a comparison among means. Polishing after ultrasonic scaler cleaning method was the most efficient treatment. Despite producing more tooth loss than the other methods, this is minimum and the remaining amount of calculus is very low.Sociedad de Ciencias Morfológicas de La Plat
Dog dental enamel ultramorphology: analysis by scanning electron microscope. Preliminary report
El esmalte de los mamíferos está constituido en un 90% por cristales de hidroxiapatita formando “prismas” y la sustancia interprismática que los rodea. Los prismas varían su forma según la especie y se organizan en algunos casos en forma paralela (Bandas de Hunter-Schreger) y, en otras, de manera entrecruzada. En el perro existe escasa información al respecto, por lo que el objetivo de este estudio fue determinar la ultramorfología del esmalte en el perro mediante microscopía electrónica de barrido. Se seccionaron dientes permanentes sanos (n=24) con disco de diamante, se les grabó la superficie seccionada con ácido fosfórico y se procesaron para ser observados con el MEB. Se midió el espesor de los prismas en diferentes sitios del esmalte. Los prismas presentaron forma hexagonal y un espesor medio de 4,4 μm. Se encontraron sectores con bandas de Hunter-Schreger y sectores de prismas entrecruzados. Se concluye que el espesor de los prismas del esmalte del perro no varía según tipo de diente ni sector de la corona, exceptuando en las cúspides donde fue más angosto. La organización prismática observada fue similar a la informada en estudios previos del esmalte del perro.Mammals´ enamel is constituted in a 90% by hydroxyapatite crystals forming "prisms" and the interprismatic substance that surrounds them.
Prisms present different shape according to the species. In some regions they are organized in parallel (Hunter-Schreger bands), and in others in a crisscross way. There is little information regarding the dog, so the aim of this study was to determine the ultramorphology of dog enamel by scanning electron microscopy (SEM). A total of 24 permanent healthy dog teeth were selected. They were cut with a diamond disc and the cut surface was etched with phosphoric acid. The teeth were processed to be studied with the SEM, and the prisms thickness was measured at different sites of the enamel. Dog prisms presented hexagonal shape, and an average thickness of 4,4 μm. Regions with Hunter-Schreger bands, and regions with cross prisms were found. In conclusion, prisms thickness of dog enamel does not vary according to the type of tooth or sector of the crown, except in the cusps where it is narrower. Prismatic organization was similar to that reported in previous dog enamel studies.Sociedad de Ciencias Morfológicas de La Plat
Compost stream as a potential biomass for humic acid production: Focus on compost seasonal and geographical variability
Compost is a voluminous stream rich in humic and fulvic acids, which may be recovered as high-added value compounds. These soluble bio-based lignin-like polymeric substances (SBO) can be extracted through a completely green process developed at pilot scale, whose main core is the hydrolytic route in aqueous solutions at relatively mild temperature (< 140 °C) at ACEA Pinerolese Industriale premises. Due to their chemical-physical properties, the SBO compounds can be used with advantage for myriads of industrial applications, from the formulation of detergents to the production of agriculture biostimulants, answering the increasing demand for bio-compound utilization. In view of LIFECAB project (LIFE16 ENV/IT/000179), the characterization of starting materials and the derived compost has been performed over four seasons and over three European countries (Italy, Greece ad Cyprus). In view of establishing a relationship between SBO molecules and compost properties, this work is a challenging opportunity for assessing the compost variability and its temporal evolution during the composting process. Analyses of pH, salinity, total carbon, total nitrogen and C/N ratio, critically assessed by means of a statistical approach, provide important information about compost composition according to the season and to the local environmental conditions
The Third Fermi Large Area Telescope Catalog of Gamma-ray Pulsars
We present 294 pulsars found in GeV data from the Large Area Telescope (LAT)
on the Fermi Gamma-ray Space Telescope. Another 33 millisecond pulsars (MSPs)
discovered in deep radio searches of LAT sources will likely reveal pulsations
once phase-connected rotation ephemerides are achieved. A further dozen optical
and/or X-ray binary systems co-located with LAT sources also likely harbor
gamma-ray MSPs. This catalog thus reports roughly 340 gamma-ray pulsars and
candidates, 10% of all known pulsars, compared to known before Fermi.
Half of the gamma-ray pulsars are young. Of these, the half that are undetected
in radio have a broader Galactic latitude distribution than the young
radio-loud pulsars. The others are MSPs, with 6 undetected in radio. Overall,
>235 are bright enough above 50 MeV to fit the pulse profile, the energy
spectrum, or both. For the common two-peaked profiles, the gamma-ray peak
closest to the magnetic pole crossing generally has a softer spectrum. The
spectral energy distributions tend to narrow as the spindown power
decreases to its observed minimum near erg s, approaching the
shape for synchrotron radiation from monoenergetic electrons. We calculate
gamma-ray luminosities when distances are available. Our all-sky gamma-ray
sensitivity map is useful for population syntheses. The electronic catalog
version provides gamma-ray pulsar ephemerides, properties and fit results to
guide and be compared with modeling results.Comment: 142 pages. Accepted by the Astrophysical Journal Supplemen
Recovery of D-limonene and energy from orange peel waste
Currently, there is not a harmonized definition of food waste. Parfitt et al. (2010) suggested the following definition: "Food losses or waste are the masses of food lost or wasted in the part of food chains leading to edible products going to human consumption". Therefore, food waste has taken on disquieting proportions worldwide in all steps of the food production and supply chain, and in industrialized countries more than 40 % of the food waste occurs at retail and consumer levels (FAO, 2014). More than one-third of the food produced for human consumption, between 1.2 and 2 billion tonnes per year (FAO, 2014), gets lost or wasted globally, equivalent to 6-10 percent of human-generated greenhouse gas emissions (Gustavsson, 2011; Vermeulen et al., 2012). Food waste is an abundant and renewable biomass for the recovery of high-added value compounds and for the production of bio-fuels, representing a valid alternative for the displacement of polluting and limited fossil fuels. Waste-to-Energy concept is supported by Directive 2008/98/EC (EU, 2008), which is the main effort of European legislation on waste. In this directive, concepts and definitions related to waste management are laid down, as well as waste management principles such as the "polluter pays principle" and the "waste hierarchy". It is of the utmost importance to integrate all of those initiatives/activities aimed at minimizing waste with high recycling targets, in order to respect and protect the environment as well as to promote process sustainability. It is necessary to abandon the idea that an improved quality of life corresponds to immediate economic growth. And, in fact, economic development itself would not be possible without safeguarding the environment and its natural resources. What is the future going to be like if we cannot guarantee the next generations with any resource? The aim of this Thesis is the valorization of by-products generated within a specific sector, namely the citrus processing industry, to help Europe become more resource efficient and sustainable. The principal objective is the evaluation of several processes aiming at the recovery of D-limonene and energy from orange peel waste (OPW), with the task of using collected experimental data for Life Cycle Assessment (LCA) inventory. In order to fulfill this purpose, first, a detailed review was written (and published), with the aim of achieving a deep knowledge on the toxicity of D-limonene, which represents the main challenge when anaerobic digestion is performed. Therefore, experimental works were performed in order to investigate several extraction techniques - including accelerated processes at moderate temperature and pressure-, anaerobic digestion valorization and pyrolysis technology. Afterwards, results were compared through LCA modelling performed by means of EASETECH, a software developed by Technical University of Denmark (DTU) and specifically dedicated to waste management. The most salient results were published on scientific journals, and this Thesis is an assortment of the Author's literature works. Therefore, this work is structured in the following sections. CHAPTER I reports a deep overview of the most relevant notions concerning citrus waste issue and the main routes implemented for the valorization of this specific waste, both in terms of recovery of high-added value compound and in terms of bio-fuels. To accomplish this, several research works were carefully reviewed in detail. CHAPTER II addresses the effect of several pre-treatment processes on anaerobic digestion, mainly focused on the inhibitory effect of D-limonene. Basic and thermal treatments as well as extractive processes were evaluated in order to select the best strategies for scale-up operation. In CHAPTER III, several anaerobic co-digestion strategies were implemented with the intent of reducing the concentration of toxicants. First, toxicity batch tests were carried out in order to experimentally determine the threshold concentrations for toxic compounds and, afterwards, four Continuous Flow Stirred Tank Reactors (CSTRs) were utilized to investigate the co-digestion process of orange peel waste with manure and/or seaweed. The experimental set-up and work were totally carried out at the Environmental DTU, supervised by Irini Angelidaki and Merlin Alvarado-Morales (from Bio-Energy Group). CHAPTER IV compares the pyrolysis process of orange peel waste with hazelnut shells, a biomass generally accepted as a suitable feedstock for thermochemical processes. After the extraction of D-limonene by Soxhlet extraction with hexane as solvent, the residual waste was subjected to a natural de-hydration at room temperature and then used as a feedstock for pyrolysis process. In CHAPTER V, an accelerated extraction at moderate temperature was suggested as alternative to traditional Soxhlet extraction, with the task of increasing D-limonene recovery yield. The energy expenditure for D-limonene extraction was evaluated in order to select the optimal operating conditions (extraction temperature, extraction time and ratio OPW-solvent). After a natural de-hydration at room temperature, the citrus residue was valorized through pyrolysis process at different heating rates. Furthermore, the Energy Sustainability Index (ESI) was estimated for pyrolysis process, taking into account the total amount of energy available in the form of pyrolytic products and the amount of energy spent to treat the waste. CHAPTER VI presents several waste management scenarios. Environmental savings and burdens were quantified by means of LCA model for mono-treatments (pyrolysis, incineration and anaerobic mono-digestion), co-treatments (four strategies of anaerobic co-digestion) and non-recovery energy processes (landfilling, composting and animal feeding). The whole modelling section was carried out at the Environmental Department of DTU, supervised by Davide Tonini. Finally, the last CHAPTER VII highlights the main results obtained in this work and depicts future perspectives for waste management
An integrated approach to energy use: the case study of the ACEA site
Currently, ACEA utilises biogas obtained from the treatment of the organic fraction of municipal solid waste for thermal and electric energy recovery through endothermic engines (3 MW, in total). By 2020, the biogas produced at the site will no longer be used as a fuel for the combined heat and power units, but it is expected to feed a purification system in order to obtain a flow of biomethane to be injected into the natural gas network. This is part of the Italian strategy to achieve the Horizon 2020 European targets aimed at promoting the renewable production of transport fuels. In order to encourage sustainability and innovative prototype technologies, ACEA has also been involved in some European research projects, in particular for the conversion of biogas into other energy carriers. furthermore, ACEA ha recently built a flexible experimental platform that can used for the validation step of prototypes in an industrial field