177,751 research outputs found
Role of animals in waste management with a focus on invertebrates’ biorefinery : An overview
No full textAnimals may at times be actively involved in waste management activities. Although occasionally still encountered today, in the past animals were used to transport wastes. Moreover, they can be of significant use in processing putrescible waste. Indeed, worms and fly larvae, while promoting biodegradation and stabilisation, may additionally represent a source of biofuels, specifically biodiesel derived from their fat, and/or of proteins from their biomass (de-fatted and non). In the regenerative system of the circular economy, where waste and resources are interchangeable, the use of animals to process waste and the consequent use of those animals to recover materials and renewable energy represent a perfect fit. This interrelationship has displayed good potential in reducing environmental impacts compared to conventional disposal methods and feed/food preparation. However, the insect-biorefinery (or better the invertebrate-biorefinery) concept should be better elucidated, particularly with regard to the implementation of best safety practices when making a chain to include waste, insects, and feed/food, and, in defining a complete and clear set of regulations. This review provides an overview of the potentially beneficial use of worms and insects in waste management, taking into consideration that enforced legislation is not currently equipped to approve the necessary guidelines aimed at ensuring a safe and well-structured application of a new invertebrate biorefinery economy, and likewise, the population has not yet been sufficiently well informed to be able to form a favourable opinion
Food waste generation and industrial uses : A review
No full textFood waste is made up of materials intended for human consumption that are subsequently discharged, lost, degraded or contaminated. The problem of food waste is currently on an increase, involving all sectors of waste management from collection to disposal; the identifying of sustainable solutions extends to all contributors to the food supply chains, agricultural and industrial sectors, as well as retailers and final consumers. A series of solutions may be implemented in the appropriate management of food waste, and prioritised in a similar way to waste management hierarchy. The most sought-after solutions are represented by avoidance and donation of edible fractions to social services. Food waste is also employed in industrial processes for the production of biofuels or biopolymers. Further steps foresee the recovery of nutrients and fixation of carbon by composting. Final and less desirable options are incineration and landfilling. A considerable amount of research has been carried out on food waste with a view to the recovery of energy or related products. The present review aims to provide an overview of current debate on food waste definitions, generation and reduction strategies, and conversion technologies emerging from the biorefinery concept
Estimation of global warming emissions in waste incineration and landfilling: An environmental forensic case study
No full textAnthropogenic emissions of greenhouse warming gases (GWG) to the atmosphere are thought to contribute to the Earth’s global warming. Among different waste management options, incineration is often considered one of the most effective and environmentally protective as demonstrated by many Life Cycle Assessment analysis. Nonetheless, depending on previous treatments that a waste may receive, such as mechanical biological treatment (MBT), landfilling could offer better possibilities than incineration in terms of GWG emissions thanks to carbon sequestration according to the “Carbon Sink” principle. The latter refers to any process that avoids the emission of GWG, for example, the biogenic carbon that is not dissimilated and remains permanently stored in a landfill, avoiding its emission to the atmosphere. The current study presents a forensic case study of municipal solid waste management in Italy; it aims at assessing the GWG [i.e., methane, carbon dioxide (CO 2 ), and nitrous oxide] released to the atmosphere by two different scenarios of a waste flow processed in a MBT: incineration with energy recovery and landfill disposal with gas recovery. For each scenario, total fluxes of GWG are estimated as the sum of: 1) emissions during waste refinery to produce refuse-derived fuel; 2) indirect emissions associated to transport; 3) process or treatment emissions derived from the waste itself (direct emissions) and from the fuel used for its treatment prior to disposal; 4) disposal emissions that result from the ultimate disposal of the waste; 5) emissions avoided as a result of useful energy or materials recovery; 6) stored or sequestered emissions due to short-cycle carbon locked up in the landfill and prevented from being returned to the atmosphere as CO 2 for longer than 100 years. Carbon sink is a fundamental phenomenon to be accounted in the study, given that, without considering it, the GWG in the landfill would considerably change (from –33.9 kg CO 2 /t DF to 250.3 kg CO 2 /t DF, DF being the dry fraction from the MBT process). According to the composition of waste and to the plant engineering for the treatment/disposal destinations assumed, landfilling results the better option in term of GWG emissions. It is worth mentioning that not only GWG should be considered in the evaluation of waste management options. Nonetheless, the results from the present study provide useful information to prove that a waste management option (landfilling), that a priori could appear less sustainable, represents, instead, an optimal solution
ChronochRt - Creating Chronological Charts
No full text<p>R package for an easy way to draw chronological charts from tables, aiming to include an intuitive environment for anyone new to R. Includes 'ggplot2' geoms and theme for chronological charts.</p>
<p>Please cite as: T. Rose & C. G. M Girotto (2024). chronochrt: Creating Chronological Charts with R. R package version 0.1.3. https://CRAN.R-project.org/package=chronochrt</p><p>Changes to version 0.1.2 * CRAN fixes (see <a href="https://github.com/r-lib/roxygen2/issues/1491" target="_blank" rel="nofollow noreferrer noopener">r-lib/roxygen2#1491</a>).</p>
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Effect of Aeration Applied During Different Phases of Anaerobic Digestion
No full textAerobic treatment has been investigated as a method to enhance putrescible substrate degradation and biogas production through anaerobic digestion (AD). A series of aeration methods has been studied in different phases of anaerobic digestion (before, during, or at a late stage of AD). Several research groups have applied aeration together with anaerobic digestion to improve hydrolysis and increase substrate conversion efficiencies. Aeration has been proven to reduce volatile fatty acids (VFA) accumulation during AD, reducing pH inhibition for methanogens, and thus increasing process yields. Aeration may represent an effective method to reduce substrates’ toxicity (e.g. sulphur compounds), particularly when digestate, resulting from their anaerobic digestion, is destined for use on the land. However, a potential drawback is represented by decreased methane production observed as a consequence of excessive soluble COD consumption prior to the AD phase. Duration and intensity of aeration, substrate type, aeration method, temperature during aeration, and air application phase are deemed important factors capable of affecting the efficiency of this treatment. The present review aims to provide a comprehensive insight into research studies performed over the past decades to test the combination of aerobic treatment and anaerobic digestion of organic substrates
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