| 1. |
- Dodoo, Ambrose, et al.
(författare)
-
Life cycle primary energy implication of retrofitting a wood-framed apartment building to passive house standard
- 2010
-
Ingår i: Resources, Conservation and Recycling. - : Elsevier. - 0921-3449 .- 1879-0658. ; 54:12, s. 1152-1160
-
Tidskriftsartikel (refereegranskat)abstract
- Here we analyze the life cycle primary energy implication of retrofitting a four-storey wood-frame apartment building to the energy use of a passive house. The initial building has an annual final energy use of 110 kWh/m(2) for space and tap water heating. We model improved thermal envelope insulation, ventilation heat recovery, and efficient hot water taps. We follow the building life cycle to analyze the primary energy reduction achieved by the retrofitting, considering different energy supply systems. Significantly greater life cycle primary energy reduction is achieved when an electric resistance heated building is retrofitted than when a district heated building is retrofitted. The primary energy use for material production increases when the operating energy is reduced but this increase is more than offset by greater primary energy reduction during the operation phase of the building, resulting in significant life cycle primary energy savings. Still, the type of heat supply system has greater impact on primary energy use than the final heat reduction measures.
|
|
| 2. |
- Eriksson, Ola, et al.
(författare)
-
Identification and testing of potential key parameters in system analysis of municipal solid waste management
- 2010
-
Ingår i: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 54:12, s. 1095-1099
-
Tidskriftsartikel (refereegranskat)abstract
- Life cycle assessment (LCA) and life cycle costing (LCC) are well-established methods used for many years in many countries for system analysis of waste management. According to standard LCA procedure the assessment should include improvement analysis, in many cases this is performed by simple sensitivity analyses. An obstacle to perform more thorough sensitivity analyses is that it is hard to distinguish input data important to the results, i.e. key parameters. This paper further elaborates sensitivity analyses performed in an environmental system analysis fora hypothetical Swedish municipality. In this paper, the method to identify and test input data that can be categorised as potential key parameters is described. The method and the results from computer simulations of the identified parameters are presented, and some conclusions are drawn regarding the robustness of the results for environmental impact from municipal solid waste management. The major conclusion is that the results are robust. Changes in results, when changing the preconditions, are often small and the changes observed do not lead to new conclusions; i.e., a change of ranking order between treatment options.
|
|
| 3. |
- Gahan, Chandra Sekhar, et al.
(författare)
-
Utilisation of steel slags as neutralising agents in biooxidation of a refractory gold concentrate and their influence on the subsequent cyanidation
- 2011
-
Ingår i: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 55:5, s. 541-547
-
Tidskriftsartikel (refereegranskat)abstract
- A study on the possibilities to utilise steel slag as neutralising agent in biooxidation of a refractory gold concentrate has been done with reference to commercial grade slaked lime. The idea has been to reduce the operating costs for neutralisation in the biooxidation plant, which is known to be the second largest operating cost. Other benefits would be savings in cost for landfilling of slag, possibilities to recycle elements present in the slag and savings of virgin limestone deposits. The slags used were an EAF slag and a slag from ladle refining; both originating from Swedish scrap based steel-making. Continuous biooxidation of the refractory gold concentrate was conducted in a single-stage 5 L reactor at a retention time of 56 h. The neutralisation capacity was determined by comparing the amount needed, per ton of feed concentrate added, to maintain the desired pH of 1.5 during steady state operation. Slaked lime had the highest neutralisation capacity with 110 kg/ton feed followed by ladle slag and EAF slag with values of 152 and 267 kg/ton feed, respectively. Sulphide mineral oxidation was similar and high in all cases although the ladle slag results were slightly better. Gold recoveries after cyanide leaching on the residues obtained were also similar and were in the range of 86–89%. However, the cyanide consumption expressed as kilogram cyanide per ton of concentrate fed to biooxidation, was double in the case of ladle slag and three times as much for the EAF slag compared to the slaked lime experiment. The increased cyanide consumption could not be explained only by the increased amount of elemental sulphur obtained in the slag experiments. The elemental sulphur formed had different reactivities as seen from the thiocyanate formation and cyanide losses due to thiocyanate formation were 16%, 32% and 40% for EAF slag, slaked lime and ladle slag, respectively. It is concluded that the ladle slag could be a possible replacement for limestone if they are mixed in proper proportions so that the microbial carbon dioxide demand is met whereas the EAF slag is less suitable due to the very fine reaction products obtained which gave operational problems with filtration and washing. To come further, experiments with the normal multi-stage biooxidation set-up with total retention time of 120 h should be performed which would increase the sulphur oxidation and eventually also reduce the cyanide consumption.
|
|
| 4. |
- Gustavsson, Jenny, et al.
(författare)
-
Retail waste of horticultural products in Sweden
- 2011
-
Ingår i: Resources, Conservation and Recycling. - : Elsevier. - 0921-3449 .- 1879-0658. ; 55:5, s. 554-556
-
Tidskriftsartikel (refereegranskat)abstract
- Waste of food is a topic of considerable policy interest. However, few studies have been done on food waste at the retail level. The aim of this study was to examine how large retail waste is for 16 different horticultural products, selected among typical fruit and vegetables. The levels of retail waste were examined in cooperation with one of the leading Swedish retail companies. The results showed that retail waste of horticultural products amounted to between 0.4 and 6.3% of store supplies for different horticultural products. The results did not show that packaging reduced waste of horticultural products.
|
|
| 5. |
- Hemström, Kerstin, 1979-, et al.
(författare)
-
Perceptions, attitudes and interest of Swedish architects towards the use of wood frames in multi-storey buildings
- 2011
-
Ingår i: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 55, s. 1013-1021
-
Tidskriftsartikel (refereegranskat)abstract
- Use of wood frames from sustainable forestry instead of non-wood frames in multi-storey buildings can reduce primary energy use and carbon dioxide emissions in construction. However, construction actors might have different perceptions towards wood frames than towards steel and concrete frames. Such perceptions may influence the actors' decision to adopt wood frames. In this study we use a web-based questionnaire to assess Swedish architects' perceptions, attitudes and interest towards steel, concrete and wood frames in multi-storey buildings (n = 412). Results indicate that the responding architects find concrete the most suitable frame material in buildings of 3-8 storeys, mainly because of the performance of concrete with regards to the engineering aspects (e.g. stability and fire safety) that were considered important in the choice of frame material. Although wood is considered the least suitable frame material, the overall attitude towards, and interest in, using wood is positive and related to the perceived environmental benefits of wood. This may derive from an increased discussion of and information about the environmental impact of buildings. Wood may be perceived as new and innovative while not considered as adequately proven as steel and concrete with regards to engineering aspects.
|
|
| 6. |
- Lazarevic, David, et al.
(författare)
-
Plastic waste management in the context of a European recycling society : Comparing results and uncertainties in a life cycle perspective
- 2010
-
Ingår i: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 55:2, s. 246-259
-
Tidskriftsartikel (refereegranskat)abstract
- A number of life cycle assessment (LCA) studies have been undertaken within the last 15 years comparing end-of-life treatment options for post-consumer plastic waste, including techniques such as: mechanical recycling, feedstock recycling, incineration with energy recovery and landfilling. These have attempted to support decisions in the formulation of waste management strategies and policies. In light of the introduction of life cycle thinking into European waste policies, specifically in relation to the waste hierarchy, a literature review of publically available LCA studies evaluating alternative end-of-life treatment options for plastic waste has been conducted. This has been done in order to: establish if a consensus exists as to the environmentally preferable treatment option for plastic waste; identify the methodological considerations and assumptions that have led to these conclusions; and determine the legitimacy of applying the waste hierarchy to the plastic waste stream. The majority of the LCA studies concluded that, when single polymer plastic waste fractions with little organic contamination are recycled and replace virgin plastic at a ratio of close to 1:1, recycling is generally the environmentally preferred treatment option when compared to municipal solid waste incineration. It has been found that assumptions relating to the virgin material substitution ratio and level of organic contamination can have a significant influence upon the results of these studies. Although a limited number of studies addressed feedstock recycling, feedstock recycling and the use of plastic waste as a solid recovered fuel in cement kilns were preferred to municipal solid waste incineration. Landfilling of plastic waste compared to municipal solid waste incineration proved to be the least preferred option for all impact categories except for global warming potential. Due to the uncertainty surrounding some assumptions in the studies, it cannot be said with confidence that the waste hierarchy should be applied to plastic waste management as a general rule.
|
|
| 7. |
- Linderholm, Kersti, et al.
(författare)
-
Life cycle assessment of phosphorus alternatives for Swedish agriculture
- 2012
-
Ingår i: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 66, s. 27- 39
-
Tidskriftsartikel (refereegranskat)abstract
- Phosphorus is an important nutrient in plant cultivation. Global reserves of phosphate rock worth miningare limited. Reuse of phosphorus in wastewater is therefore important. This LCA study assessedthe environmental impact of four ways to supply Swedish agriculture with phosphorus fertiliser ofacceptable quality as regards cadmium content: mineral fertiliser; certified sewage sludge; struvite(MgNH4PO4·6H2O) precipitated from wastewater; and phosphorus recovered from sludge incineration.These were examined with respect to impacts on global warming, eutrophication, energy demand andcadmium flows to farmland. The functional unit chosen was 11 kg P (25.2 kg P2O5) to agricultural land,which was the average phosphorus output (removal with harvest) per hectare from Swedish farmlandin 2007. Using sewage sludge directly on farmland was the most efficient option in terms of energyand emissions of greenhouse gases, but also added most cadmium to the soil. Phosphorus recovery fromincinerated sludge was the most energy demanding option and gave most emissions of greenhouse gases.Despite great concerns about cadmium in Swedish fertilisers and sludge, it was found that almost no regularanalyses for cadmium are made on imported food by the authorities, although food imports areconstantly increasing. Total imports of cadmium with food are therefore unknown.
|
|
| 8. |
- Lundkvist, Katarina, et al.
(författare)
-
Optimisation of a centralised recycling system for steel plant by-products, a logistics perspective
- 2013
-
Ingår i: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 77, s. 29-36
-
Tidskriftsartikel (refereegranskat)abstract
- This paper focuses on the optimisation of a recovery strategy for waste materials and thereby improved material efficiency in the iron and steel industry. A joint venture between four Nordic steel plants is considered in order to recycle materials otherwise mainly put to landfill, i.e. dusts and sludges from the steel production processes. Process integration (PI) was used to investigate the possibilities for recovering the materials by developing a system optimisation model of the steel plants and integrating a dedicated material upgrading process in the system. This work aims to develop a model suitable for analysing and finding a logistic solution needed to achieve a common recycling system by studying material supply, required material storage, shipping system and shipping frequency. The developed optimisation model is presented, using a case study of the steel production plants with the dedicated upgrading process and the logistics system. The prospect for shipping materials from the steel production sites to the material upgrading process site as well as the material supply to the upgrading unit is essential in the system analysis. A mathematical optimisation model based on mixed-integer linear programming (MILP) for the common system is presented. The integration of the dedicated material upgrading process show a system in balance regarding the materials generated and processed in the upgrading unit. Generated material amounts suitable for the upgrading process can be fully recovered thereby decreasing the landfilled amounts from the four steel production sites.
|
|
| 9. |
- Ordonez, Maria Isabel, 1981, et al.
(författare)
-
Collaboration between design and waste management: Can it help close the material loop?
- 2013
-
Ingår i: Resources Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 72, s. 108-117
-
Tidskriftsartikel (refereegranskat)abstract
- In order to explore the current relationship between industrial design and waste management (WM), a semi-structured interview study was carried out with 25 professionals from WM and designers that have worked with waste. The main aim was to learn about the collaborative work between these two areas and to investigate whether collaboration could help to incorporate material resources into production. The study reveals that designers and WM professionals regard the relation between disciplines in different ways, being more or less centered in their own disciplines. The designers interviewed, however tend to have a wider impression of this relation. This, together with the lack of understanding of the other's role and a fundamental scale difference when dealing with material flows were identified as the main barriers to better and more frequent collaboration. Even though some examples of collaborative work were found, they were not significant enough to have any noticeable effect on the WM system. In order to facilitate future collaboration, the contribution of the presented work is to identify areas for collaboration and suggest initial solutions for overcoming the barriers encountered to help to close the material loop
|
|
| 10. |
- Owusu, V., et al.
(författare)
-
Do economic incentives affect attitudes to solid waste source separation? : Evidence from Ghana
- 2013
-
Ingår i: Resources, Conservation and Recycling. - : Elsevier. - 0921-3449 .- 1879-0658. ; 78, s. 115-123
-
Tidskriftsartikel (refereegranskat)abstract
- This paper examines the willingness of urban households in Ghana to accept economic incentives to participate in solid waste source separation. Low income households were less inclined to accept cash incentives than middle or high income households indicating that other factors than purely costs for waste management are important for households to participate in source-separation of waste. Perceptions on health and sorting and the availability of open space in the households were important for the willingness to accept incentives for source separation. The empirical findings indicate that household-level solid waste separation is positively influenced by gender (female) and sorting or health-related perceptions on source separation. About 80% of the households are willing to accept cash incentive of GH¢1.6374 (US$1.6347) per month to participate in source separation, and the mean cash incentive per month is GH¢1.2186 (US$1.2166). Fruitful solid waste management policy recommendations based on the empirical magnitudes and directions are made.
|
|
