1,721,026 research outputs found
Use of energy footprint analysis to determine the best options for management of glass from household waste
No full textEnergy and material flow of waste-processing operations
No full textAlthough waste continues to be produced in large quantities—the rate of increase in waste production being more or less in line with the rate of growth in the economy—society is still grappling with the problem of sustainable waste management. One of the best ways to assess sustainability is in terms of mass and energy balance. A project at the University of Southampton looked at the ‘energy footprint’ for waste management. The project brought together data from existing work on waste quantities, materials flow and mass balance studies for a range of materials including paper, glass, plastics, metals and organics. These data have been combined with information on the energy requirements for different types of collection and processing systems for reuse, recycling, recovery and disposal of such materials. Taking into account energy benefits from any of these options, the information has been used to produce an energy and materials balance, and the results show the energy footprint and materials output of the current waste management practices in Southampton. This work allows exploration of alternative methods and highlights areas where insufficient information is available, or where improvements in collection or processing technologies could have a significant impact on the final energy and material balance. The greater Southampton area was used as a case study, but the methods developed could be applied to other areas by modifying the input data
How leachate stress modified the population dynamics of two macro-invertebrates: water quality improvements by constructed wetlands?
No full textAcute and sub-lethal toxicity tests to monitor the impact of leachate on an aquatic environment
No full textIn this study, a specific landfill leachate (1200 mgl?1 COD and 600 mgl?1 BOD5) was used to develop a standardised short-term acute and longer-term sublethal ex-situ toxicity testing programme, in order to determine the potential ecological implications of leaching contaminants reaching the water table. Bioassays were undertaken with juvenile Gammarus pulex and Asellus aquaticus macro-invertebrates. Preliminary acute test variables included static and static renewed flow rates for 96-h, starved and fed specimens, and aerobic and oxygen depleting conditions. However, regardless of any test variable, the lethal concentration (LC50) for A. aquaticus remained at 12.3% v/v leachate in deionised water, whilst that for G. pulex was only 1%. Sublethal toxicity was judged on the basis of frequency of births and the growth rate of newly born individuals. Tests showed that even a dilution as high as 1:66- would influence the fecundity of a Gammarus population, whilst a dilution of 1:20 would affect the size of an Asellus breeding colony
Analysis of energy footprints associated with recycling of glass and plastic - case studies for industrial ecology
No full textRoundput [Int. J. Sustainable Dev. World Ecol. 8 (2001) 29] is one of the most important principles of the development of both natural and industrial ecosystems, and is especially important for analysis of an ecosystem's dynamics and overall functioning. as it is related to an extent to which energy and matter are recycled and used in a cascade-type operation. Here we argue. using two modelling case studies from the UK and Switzerland, that increasing recycling rates for plastic and glass would improve the energy budget of waste management programmes, and, therefore, benefit the corresponding industrial ecosystems. In the first case study we show that the major source of energy savings from glass recycling is through increased use of cullet in glass manufacture (5.4% reduction in total energy consumption with 100% glass recycling when compared to the present-day situation). In terms of energy consumption, recycling is the preferred waste management option, even if a large proportion of the recycled glass is diverted for use as aggregates. Further energy savings could be achieved by introduction of a city-wide kerbside collection scheme, which would result in an estimated maximum reduction (100% recycling rate) of 7.6% in energy consumption for processing of the Southampton household glass wastes. In the second case study we compare the situation in which all wastes are burnt at a MSWI plant with two scenarios assuming that 8.1% of the plastic is diverted into a cement kiln (mixed plastics; scenario 1) or a mechanical recycling plant (polyethylene, polypropylene, polystyrene; scenario 2). The resulting net primary energy consumption values for both scenario 1 (5.85E8 MJ or 60% relative to the reference scenario) and 2 (7.46E8 MJ or 76.6% relative to the reference scenario) use less primary energy than the reference scenario (9.74E8 MJ). This means that, from the point of view of resource consumption, the diversion of plastics waste away from the MSWI plant has a beneficial effect. Therefore, the increased recycling of glass and plastic would benefit the industrial ecosystems in terms of energy savings. This is similar to the patterns observed in most natural ecosystems, and a careful consideration of this similarity within a framework of industrial ecology should help to reduce the conflict between the two systems
Contemporary applications of the interdisciplinary waste management research: Case studies of algal biodiversity in the WSP and energy footprint of municipal wastes
No full textThis paper describes two interdisciplinary waste management case studies coordinated by the University of Southampton. The first case study addresses the issue of algal species composition in wastewater treatment facilities situated in Kazakhstan. Algal populations in four experimental waste stabilisation ponds fed at surface loading rates from 50-300 kg BOD ha-1 day-1 were monitored for seven months, including a period between late November and mid March when the ponds were frozen. Cell counts and species identification were performed five times a week and biomass concentration was estimated weekly. During winter only very small numbers of algae were observed in samples taken from below the ice. Once the ice melted there was a rapid increase in algal numbers linked with rising water temperature. It was also apparent that cell numbers increased at a faster rate in the pond with the lightest winter load. During the whole period of operation the algal population was dominated by a small number of species, with 80% of the cell count attributable to no more than 3 species in each pond, but there were considerable differences between ponds. When considered as biomass rather than cell numbers, single species dominance was even more apparent apart from in one pond where diversity increased significantly. In line with other studies, there is an indication that higher loadings result in lower diversity. With the current set of results, it was difficult to interpret changes in the population structure as a function of loading or any other analytical determinant. However, there is an indication that the system appears to be dominated by small species in the initial warm up period, maturing to greater species diversity, and larger species, by mid summer.The second case study describes a project set up to understand, quantify and model energy usage associated with the collection, separation, processing and disposal of Municipal Solid Wastes. It illustrates the energy footprint analysis using data on the paper/card fraction within household waste. The mass and energy balances for the different processes/stages involved with dealing with the waste stream in Southampton are simulated using a specially designed model. The model starts from the point where the material becomes ‘waste’ and follows it through until disposal and/or processing. It accounts for recycling via bring-sites (both recycling banks and Household Waste Recycling Centres) and also via kerbside collection schemes, and disposal via landfill and thermal recovery of heat. Critically, the model not only takes into account the energy consumed during processing/disposal but also transport energy consumption. The results show that the major source of energy savings from paper/card recycling is from increased use of the recycled material in paper/card manufacture, due to the decrease in energy required to produce paper from this material. There is an ~5% reduction at a maximum recycling rate of ~52%, compared to the present-day rate (18.1%,) with recycling through the PaperChain? scheme (only collects newspaper/magazines/leaflets).The savings increase to ~9% (at ~87% recycling rate) if a city-wide dry recyclables scheme is introduced to replace the PaperChain scheme. This increase is largely due to the fact that more sub-categories of paper/card are collected by the dry recyclables scheme.In terms of energy consumption, incineration without recycling would be the preferred waste management option. However, the calorific value of the residual waste stream is not significantly affected by removal of paper/card through increased recycling. Thus, a combination of recycling and incineration of the residual waste would also be an option
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
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