The four papers of this dissertation explore themes related to waste prevention, the system boundaries, functional units and scale of life cycle assessments (LCAs) of municipal solid waste (MSW) management, as well as the transparency and consistency of the application of LCA methods. The first paper is a comparative analysis of the methodological choices and transparency of 20 LCAs of MSW that were recently published in peer-reviewed journals, and includes a comparison of their midpoint level impact values using statistical indicators. The second paper proposes a conceptual model, designated WasteMAP (Waste Management And Prevention), for evaluating LCAs of MSW which incorporate waste prevention. In WasteMAP, waste prevention through dematerialization is viewed as analogous to waste treatments so long as it does not affect the functional output (product services) of MSW-generating product systems. Papers 3 and 4 comprise the WasteMAP LCA case study. Paper 3 depicts product LCAs of wine and spirit packaging (conventional, lightweight and refillable, each type generating different quantities of waste) at the scale of the individual package and the municipality. At the municipal scale, the LCAs address impacts from the wine and spirit packaging supplied in the City of Toronto, Canada in 2008, and a waste prevention scenario which substitutes lighter weight and reusable containers. The lowest endpoint level impacts out of the five container types studied were associated with refillable containers and aseptic cartons. Paper 4 addresses the Toronto MSW management system and applies the WasteMAP model to allow for the comparison, on a functionally equivalent basis, of the LCA results of a reference scenario, based on 2008 data, with a scenario incorporating six types of waste prevention activities (prevention of unaddressed advertising mail, disposable plastic bags, newspapers, lightweight and refillable wine and spirit packaging, and yard waste). The findings highlight the benefits of waste prevention, and the relative significance of the decision to account for recycled content when modelling waste prevention. The endpoint level impact assessment results using the ReCiPe and Impact 2002+ evaluation methods are in keeping with the assumption in the waste hierarchy that waste prevention has a superior environmental performance.

Environmental metrics play a significant role in behavioural change, policy formation, education, and industrial decision-making. Life Cycle Assessment (LCA) is a powerful framework for providing information on environmental impacts, but LCA data is under-utilized, difficult to access, and difficult to understand. Some of the issues that are required to be resolved to increase relevancy and use of LCA are accessibility, validation, reporting and publication, and transparency. This thesis proposes that many of these issues can be resolved through the application of open frameworks for LCA software and data. The open source software (OSS), open data, open access, and semantic web movements advocate the transparent development of software and data, inviting all interested parties to contribute. A survey was presented to the LCA community to gauge the community’s interest and receptivity to working within open frameworks, as well as their existing concerns with LCA data. Responses indicated dissatisfaction with existing tools and some interest in open frameworks, though interest in contributing was weak. The responses also pointed out transparency, the expansion of LCA information, and feedback to be desirable areas for improvement. Software for providing online LCA databases was developed according to open source, open data, and linked data principles and practices. The produced software incorporates features that attempt to resolve issues identified in previous literature in addition to needs defined from the survey responses. The developed software offers improvements over other databases in areas of transparency, data structure flexibility, and ability to facilitate user feedback. The software was implemented as a proof of concept, as a test-bed for attracting data contributions from LCA practitioners, and as a tool for interested users. The implementation allows users to add LCA data, to search through LCA data, and to use data from the software in separate independent tools.. The research contributes to the LCA field by addressing barriers to improving LCA data and access, and providing a platform on which LCA database tools and data can develop efficiently, collectively, and iteratively.

Over recent decades, environmental regulations on wastewater treatment plants (WWTP) have trended towards increasingly stringent nutrient removal requirements for the protection of local waterways. However, such regulations ignore the other environmental impacts that might accompany the apparent improvements to the WWTP. This PhD thesis used Life Cycle Assessment (LCA) to quantify these environmental trade-offs, and so better inform policy makers on the wider benefits and burdens associated with wastewater treatment. A particular focus was also given to the generation of methane and nitrous oxide in wastewater systems, since the quantification of greenhouse gas (GHG) emissions from WWTPs is presently a substantial area of uncertainty. Rapid changes to the GHG regulatory landscape mean that this level of uncertainty, now represents an unacceptable business risk for many water utilities. Specifically, there were three research objectives of this thesis: Research Objective No.1 – Environmental optimisation of wastewater treatment systems – For typical receiving environments, the optimum wastewater treatment system configuration is not necessarily at the limit of best practice for nutrient removal. The LCA approach to this research objective was divided into two stages. In stage I, a comprehensive desk-top life cycle inventory of ten different wastewater treatment scenarios was completed. The scenarios covered six process configurations and treatment standards ranging from raw sewage to advanced nutrient removal. It was shown that physical infrastructure, chemical usage and operational energy all increased with the level of nutrient removal. These trends represented a trade-off of negative environmental impacts against improved local receiving water quality. In stage II of the LCA, a quantitative life cycle impact assessment of the ten scenarios, referenced against Australian normalisation data, was completed. From a normalised perspective against Australian society, the contribution of WWTPs to headline issues such as global warming and energy consumption was found to be very small. The more prominent environmental impact categories were eutrophication due to nutrient discharge and toxicity issues, due to heavy metals in biosolids. There existed a broader environmental trade-off for nutrient removal, that could only be justified by society and regulators implicitly placing higher value on local water quality, than on other global environmental pressures. In light of this quantitative LCA, regulatory agencies should consider the broader environmental consequences of their policies such as the Queensland Water Quality Guidelines. It is suggested that the scope of WWTP licensing considerations should be widened from a singular focus on water quality objectives, to a more comprehensive LCA-based approach. Research Objective No. 2 – Quantification of nitrous oxide emissions from biological nutrient removal (BNR) wastewater treatment plants – Current GHG assessment methods for wastewater treatment plants are grossly inaccurate because of significant unaccounted N2O emissions. The research for objectives two and three was funded by the Water Services Association of Australia (WSAA), which is the peak body of the Australian urban water industry. Thus, whilst the earlier LCA results suggested that GHG emissions from WWTPs were insignificant from a national perspective, the industry is actually very engaged on this issue from an environmental responsibility and business risk perspective. This PhD study adopted a rigorous mass balance approach to determine N2O-N generation at seven full-scale WWTPs. The results varied considerably in the range 0.006 – 0.253 kgN2O-N generated per kgNdenitrified (average: 0.035 +/- 0.027). These results were generally larger than the current default value assumed in the National Greenhouse and Energy Reporting (Measurement) Technical Guidelines (i.e. 0.01 kg N2O-N.kgN-1denitrified). High N2O-N generation was shown to correspond with elevated bulk NO2--N concentrations in the bioreactor. The results also suggested that WWTPs designed for low effluent TN have lower and less variable N2O generation than plants that only achieve partial denitrification. Research Objective No.3 – Quantification of methane emissions from low-strength wastewater collection systems – Current default GHG assessment methods for sewerage systems are grossly inaccurate because of significant unaccounted CH4 emissions from rising mains. Presently, international GHG guidelines state that “wastewater in closed underground sewers is not believed to be a significant source of methane” (IPCC, 2006). However, the results of this PhD research demonstrated that methane generation in rising main sewers is substantial. It was shown that dissolved methane concentrations were dependent upon pipeline geometry and sewage residence time. Consequently, it was possible to develop a simple, yet robust, theoretical model that predicted methane generation from these two independent parameters. This model provides a practical means for water authorities globally to make an estimate of the currently unaccounted methane emissions from pressurised sewerage systems.

Over recent decades, environmental regulations on wastewater treatment plants (WWTP) have trended towards increasingly stringent nutrient removal requirements for the protection of local waterways. However, such regulations ignore the other environmental impacts that might accompany the apparent improvements to the WWTP. This PhD thesis used Life Cycle Assessment (LCA) to quantify these environmental trade-offs, and so better inform policy makers on the wider benefits and burdens associated with wastewater treatment. A particular focus was also given to the generation of methane and nitrous oxide in wastewater systems, since the quantification of greenhouse gas (GHG) emissions from WWTPs is presently a substantial area of uncertainty. Rapid changes to the GHG regulatory landscape mean that this level of uncertainty, now represents an unacceptable business risk for many water utilities. Specifically, there were three research objectives of this thesis: Research Objective No.1 – Environmental optimisation of wastewater treatment systems – For typical receiving environments, the optimum wastewater treatment system configuration is not necessarily at the limit of best practice for nutrient removal. The LCA approach to this research objective was divided into two stages. In stage I, a comprehensive desk-top life cycle inventory of ten different wastewater treatment scenarios was completed. The scenarios covered six process configurations and treatment standards ranging from raw sewage to advanced nutrient removal. It was shown that physical infrastructure, chemical usage and operational energy all increased with the level of nutrient removal. These trends represented a trade-off of negative environmental impacts against improved local receiving water quality. In stage II of the LCA, a quantitative life cycle impact assessment of the ten scenarios, referenced against Australian normalisation data, was completed. From a normalised perspective against Australian society, the contribution of WWTPs to headline issues such as global warming and energy consumption was found to be very small. The more prominent environmental impact categories were eutrophication due to nutrient discharge and toxicity issues, due to heavy metals in biosolids. There existed a broader environmental trade-off for nutrient removal, that could only be justified by society and regulators implicitly placing higher value on local water quality, than on other global environmental pressures. In light of this quantitative LCA, regulatory agencies should consider the broader environmental consequences of their policies such as the Queensland Water Quality Guidelines. It is suggested that the scope of WWTP licensing considerations should be widened from a singular focus on water quality objectives, to a more comprehensive LCA-based approach. Research Objective No. 2 – Quantification of nitrous oxide emissions from biological nutrient removal (BNR) wastewater treatment plants – Current GHG assessment methods for wastewater treatment plants are grossly inaccurate because of significant unaccounted N2O emissions. The research for objectives two and three was funded by the Water Services Association of Australia (WSAA), which is the peak body of the Australian urban water industry. Thus, whilst the earlier LCA results suggested that GHG emissions from WWTPs were insignificant from a national perspective, the industry is actually very engaged on this issue from an environmental responsibility and business risk perspective. This PhD study adopted a rigorous mass balance approach to determine N2O-N generation at seven full-scale WWTPs. The results varied considerably in the range 0.006 – 0.253 kgN2O-N generated per kgNdenitrified (average: 0.035 +/- 0.027). These results were generally larger than the current default value assumed in the National Greenhouse and Energy Reporting (Measurement) Technical Guidelines (i.e. 0.01 kg N2O-N.kgN-1denitrified). High N2O-N generation was shown to correspond with elevated bulk NO2--N concentrations in the bioreactor. The results also suggested that WWTPs designed for low effluent TN have lower and less variable N2O generation than plants that only achieve partial denitrification. Research Objective No.3 – Quantification of methane emissions from low-strength wastewater collection systems – Current default GHG assessment methods for sewerage systems are grossly inaccurate because of significant unaccounted CH4 emissions from rising mains. Presently, international GHG guidelines state that “wastewater in closed underground sewers is not believed to be a significant source of methane” (IPCC, 2006). However, the results of this PhD research demonstrated that methane generation in rising main sewers is substantial. It was shown that dissolved methane concentrations were dependent upon pipeline geometry and sewage residence time. Consequently, it was possible to develop a simple, yet robust, theoretical model that predicted methane generation from these two independent parameters. This model provides a practical means for water authorities globally to make an estimate of the currently unaccounted methane emissions from pressurised sewerage systems.

This study begins with a review of the concept of sustainability and sustainability indicators in the context of the pig and poultry industries in Santa Catarina State (SC), in Southern Brazil, and proposes an approach to the development of sustainability indicators for these industries. A review of the background and current situation of the pig and poultry industries in SC revealed that they are well organised into vertically integrated production systems and are regarded as being very competitive in world markets from technical and economic points of view. In 2002, SC produced 24% of total pork and 20% of total chicken production in Brazil in 2002, but this State has an area of only 95,000 km2, which amounts to just 1.1% of the country. SC also contributed 66% of pork exports and 54% of poultry exports from Brazil in 2002. So far the pig and poultry industries in SC have developed successfully, but recent changes towards more intensive production methods have resulted in much concern being expressed by the community, as the environmental impact of waste produced in the region has increased. The review of literature showed that in order to be sustainable, the pig and poultry industries in SC should acknowledge the concept of the “triple bottom line” and the principles of ecologically sustainable development. These include (i) biophysical or environmental sustainability, (ii) economic viability and (iii) social sustainability as criteria to guide industry development. The sustainability of the pig and poultry industries is influenced by local, regional, national and global factors which operate on several scales, and which in turn, indicate the need to use a multi-dimensional approach, combining environmental, economic, and social attributes. This study used a combination of qualitative and quantitative methods and was completed in four phases. In the first phase, an electronic survey of 205 stakeholders (complemented by 60 interviews with farmers) was undertaken to identify their views and perceptions of what sustainability meant to them. The survey was also designed to obtain stakeholders’ views on a suggested list of sustainability indicators. In Phase 2, the findings of the e-survey were discussed with panels of key industry stakeholders in 4 focus group discussions with of 47 participants to develop the list of indicators. In the third phase, a streamlined Life Cycle Assessment (LCA) study was conducted, to quantify the flows of materials, energy and of natural resource uses and to assess environmental impact. Finally, in Phase 4, stakeholder feedback was sought in 9 meetings to discuss and refine preliminary results and conclusions from the previous three phases of work. In the LCA the environmental burdens produced by typical intensive pig and poultry production systems were quantified and the contribution to each of nine selected environmental effects was estimated. The functional units (FU) were 1 tonne of live weight (LW) of pigs and 1 tonne of LW of chickens delivered to the gate of the abattoir. The boundaries of the systems analysed included the processes of producing fertilisers, feed products (maize and soybeans), energy, fuel, pesticides, production of rations, production of pigs and chickens and transportation required during all stages until the pigs and chickens are delivered to the abattoir. Data were collected from a variety of sources, including pig and poultry industry operators, research institutions, and agribusiness analysts from SC, as well as publicly available databases. Identified environmental hotspots in pig production were greenhouse gas emissions, acidification, and eutrophication, particularly from ration production and waste management. Environmental hotspots for poultry production reflect the high use of energy and pesticides, particularly associated with ration production from soybeans. The study concluded that although economic performance is competitive in world markets, most producers were operating outside the boundaries of sustainability because of inadequate waste management and excessive waste produced in a small geographical area, beyond the assimilation capacity of the local environment. This also causes other environmental effects (such as offensive odours, and increased numbers of blackflies, and houseflies), which were not quantified in the LCA study, but which were regarded as very important issues by stakeholders in the survey and focus group discussions. While comparing the overall environmental impact of producing 1 FU of pigs and poultry, this study concluded that under current production systems, pigs cause 68% greater impact than chickens. The key indicators proposed to assess the sustainability of the pig and poultry industries in SC were grouped into physical or environmental, economic, and social indicators. For physical and environmental indicators, monitoring the natural resource condition is the key indicator and requires measurement of attributes such as manure load per area of land and nutrient balance (P and K), soil condition, water use and water quality, agricultural plant species diversity, impact on native vegetation, and chemical residues in products. Among the economic indicators, long-term real net farm income and the industries’ overall competitiveness in national and international markets are key indicators. Attributes to measure these indicators are real net farm income, cost of production, farmer’s terms of trade, total factor productivity, and disposable income per farm household. Other farm level technical indicators which influence the economic outcome, such as feed conversion and productivity indices for pigs and poultry, also need to be monitored. For social indicators, the age structure and gender balance of the agricultural workforce, farmers’ managerial skills and level of training, as well as access to basic services, such as health, education, communications, and electricity in rural communities, are the key sustainability indicators. This study made four main contributions to knowledge: (a) the views and perceptions about sustainability among pig and poultry stakeholders were identified; (b) the environmental impacts of pig and poultry production were quantified and compared; (c) a set of key sustainability indicators for the pig and poultry industries was developed and validated; and (d) a framework for change towards sustainability and policy guidelines were suggested. The overall conclusion of the study is that, to be sustainable, the pig and poultry industries need to adjust their management practices, policies, and development strategies to incorporate the principles of ecologically sustainable development. Feeding strategies and methods of grain production have much influence on the key points of environmental impact, such as global warming, pesticides, and energy consumption. Waste management, however, has the greatest local impact, because of water and soil pollution and reduction in the quality of life due to offensive odours, blackflies, and houseflies. Sustainability indicators can thus assist to drive the industries to adopt improvements in the production systems to achieve better environmental performance. Although the findings of this study are confined to SC, the principles are generally applicable to other similar livestock industries in other places. The main justification for conducting this study rests on the increasing demands by the government, community and industry stakeholders for initiatives to reduce the impact of the pig and poultry production on the environment, while maintaining and enhancing its economic competitiveness in global markets and continuing to deliver important social benefits.

Coal-fired electricity production is the major emitter of CO2 and other greenhouse gases including NOx and SOx. Microalgae-based CO2 mitigation systems have been proposed to reduce the net CO2 emission from coal-fired power plants. This study focused on developing an optimum culture media and exploring the possibilities for recycling nutrients, which were added as commercial mineralized chemicals at the beginning of cultivation. In order to release the nutrients embedded in the cells so that they can be used as a nutrient source for new cells, Scenedesmus biomass was digested by anaerobic bacteria. Results showed that thermal pretreatment enhanced the methane production rate for the first 7 days of digestion. Three operational factors were tested: heating temperature, heating duration and NaOH dosage. The combination of 10 min heating with 3~6% NaOH at 50 °C gave the highest cell wall destruction for all samples except oven-dried algae. The anaerobic digestate, rich in mineralized nutrients including ammonium and phosphate, potassium and magnesium ions, was tested as a possible nutrient source for the algae cultivation. To cope with the high solid content of the digestates, the dosage of the digestates was reduced or the solid particles were removed prior to addition to the microalgae. Both approaches worked well in terms of providing nutrients with minimal effect on light penetration. Using digestates without any sterilization did not cause contamination or other deleterious effects on the Scenedesmus growth rate. Harvesting microalgae cells was critical to ensure a continuous and robust growth rate. The used media could be recycled at least four times without altering the algae growth. Nutrient replenishment was the key for a healthy culture when used media was incorporated. The combination of used media and digestates can sustain a normal algae growth. Life cycle assessment was conducted on the system including the photobioreactor, the anaerobic digester, the biomass settling and dewatering and used media and nutrient recycling. Considering methane as the energy source, the overall energy return of the system was 2.4. CO2 mitigation rate was about 39% under current mitigation system.

Understanding the energy input and emissions resulting from the development of biofuels is important to quantify the overall benefit of the biofuel. As part of the On-Farm Biomass Processing project, a life cycle assessment (LCA) was conducted on the process to harvest and transport agricultural crop residues ready for processing into biofuel. A Microsoft Excel model was developed that inventories the entire life cycle of the process, including incorporation of stochastic analysis within the model. The LCA results of the agricultural equipment manufacture are presented, along with the results of each step of the process, including fertilizer addition, single pass harvest, double pass harvest, and transport from the field to processing facility. Various methods of analyzing co-products are also presented for the single pass harvesting step, in which comparisons between market based, mass based and process-purpose based allocation methods are reviewed. The process-purpose based method of fuel consumption difference between combine operation in conventional harvest versus single pass harvest is determined to be the most realistic of the process. A detailed comparison of the energy and emission differences between single pass and double pass harvesting is given, along with the total LCA results of harvesting and transporting the biomass.

Made available in DSpace on 2014-10-09T12:27:07Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:08Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

La prise en compte des impacts environnementaux liés à la Fabrication Additive (FA) est un sujet encore en développement et loin d'être consolidé. Cette thèse tente de répondre à la question suivante: Comment identifier et maîtriser les impacts environnementaux liés à la mise en usage des technologies de Fabrication Additive ?Une approche centrée sur l’analyse de scénarios d’usages a été appliquée. Trois scénarios ont été identifiés et étudiés: 1) La Fabrication Personnelle; 2) l’Utilisation commerciale de la FA et 3) l’Utilisation Industrielle de la FA. L'analyse de la littérature et l’application de la méthode d’Analyse du Cycle de Vie – ACV ont fourni les données nécessaires afin d’identifier les différents hotspots environnementaux dans chaque scénario.Pour le cas de la « Fabrication Personnelle », l'étude souligne l'importance de mettre en évidence les aspects humains. La façon dont les gens utilisent la technologie génère bien souvent plus d’impact que la technologie elle-même. Pour le cas du scénario «Utilisation Commerciale», c’est la phase de production qui génère le plus d'impacts environnementaux, en raison de la consommation d’énergie du processus d'impression. Les résultats du scénario « Utilisation Industriel», avec l’utilisation de la technologie EBM, indiquent que la consommation d’énergie du processus d'impression, la fabrication de poudre, ainsi que les processus de Finition sont les principales sources d’impacts.Les résultats des trois études ont été analysés et rassemblés de manière à concevoir un cadre systémique montrant les contributeurs aux impacts dans le cas de la mise en usage de technologies de FA. Quatre groupes de contributeurs ont ainsi été identifiés en lien avec: le produit, le processus d'impression (aspects techniques), et le niveau d'expérience de l'utilisateur en matière de CAO et d'impression (aspects humains). Pour chaque groupe, plusieurs contributeurs ont été associés (consommation d’énergie, masse du produit, temps d’usage de la CAO,…). A partir de ce cadre, nous avons pu construire un modèle simplifié pour l’ACV adapté au cas de la mise en usage de la FA. Il a donné lieu à l’élaboration d’un démonstrateur pour estimer les impacts environnementaux liés à la mise en usage de la fabrication additive. / The subject of the environmental impacts related to Additive Manufacturing is evolving and far from being consolidated. This thesis tries to answer the following question: How to identify and control the environmental impacts associated to the use of Additive Manufacturing technologies? An approach centred on scenarios was applied. Three specific scenarios were identified and studied: 1) Personal Fabrication; 2) Business use of AM and 3) Industrial use of AM. Literature analysis and the use of the Life Cycle Assessment-LCA approach provided accurate data to identify the different hotspots of environmental impacts in each scenario.In the Personal Fabrication case, the study highlights the importance of placing a greater focus on the Human aspects. The way people use the technology often generates more impacts than the technology itself. In the ‘Business’ scenario the findings show that the energy consumed in Production phase is the most representative phase in terms of environmental impacts. Results from the ‘Industrial’ scenario using EBM technology suggests that the energy consumption of the Printing Process, the powder manufacturing, as well as the Post-treatment process are the main sources of the environmental impacts.The results of the three studies were analysed and gathered in such a way to design a systemic framework of impacts in the case of AM use. Four group of impacts drivers are recognised: The product and the Printing Process (Technical aspects) and the User’s level of experience in CAD and Printing (Human Aspects). For each group, several impact contributors are identified (product height, CAD use time, etc.). From this framework, an adapted LCA model was designed and a software concept was created to estimate the environmental impacts related to use of AM technologies.

abstract: In recent years, the length of time people use and keep belongings has decreased. With the acceptance of short-lived furniture and inexpensive replacements, the American mentality has shifted to thinking that discarding furniture is normal, often in the guise of recycling. Americans are addicted to landfills. The high cost of landfill real estate and other considerable ecological impacts created by the manufacturing of furniture should persuade people to give their belongings a longer life, but in reality, furniture is often prematurely discarded. This grounded theory study takes a multi-method approach to analyze why some types of furniture are kept longer and to theorize about new ways to design and sell furniture that lasts well past its warranty. Case studies bring new insight into designer intention, manufacturer intent, the world of auction-worthy collectables and heirlooms, why there is a booming second-hand furniture market and the growing importance of informed interior designers and architects who specify or help clients choose interior furnishings. An environmental life cycle assessment compares how the length of furniture life affects environmental impacts. A product's life could continue for generations if properly maintained. Designers and manufacturers hoping to promote longevity can apply the conclusions of this report in bringing new pieces to the market that have a much longer life span. This study finds areas of opportunity that promote user attachment, anticipate future repurposing, and provide services. This thinking envisions a paradigm for furniture that can re-invent itself over multiple generations of users, and ultimately lead to a new wave of desirable heirloom furniture. / Dissertation/Thesis / M.S.D. Design 2011