The starting point for this thesis project is the increasing intense demands of using Life Cycle Assessment (LCA) to improve the environmental performance of projects, i.e. theFive-hundred-meter Aperture Spherical radio Telescope project(FAST project) inChina. As a prevailing systematic and strategic assessment tool, LCA is used to evaluate and assess all environmental impacts of products, services and industrial processes from cradle to grave. It is also well recognized and practiced to achieve the goal of sustainability.   Following the increasing trend of sustainable development, the idea of conducting LCA technique is gaining more support from the governments, local authorities and institutes inChina. Still, recent researches have only focused on the technical issues of this tool as such, rather than the context it is involved in. To give a broader perspective instead, this thesis focuses on how to make the rankings and quantitative eco-files generated from LCAs be understood more effectively and easily by the decision makers. An effective and comprehensive map of life cycle assessment building on the results of life cycle assessment is presented.This map in this thesis is named as CLCA. Through ranking and mapping the complicated and recondite environmental performance information from the LCAs, a holistic and systematic view can be provided to the decision makers. Thus, to some extent, this CLCA approach can lend support to strategic decisions making and sustainable development.   For this purpose, literature on LCA and literature from relevant disciplines are reviewed. The empirical analysis of FAST project sheds light on that it is necessary to develop a new method that can contribute to convertingcomplicated and reconditedata into a comprehensive and visualized one. Therefore, a survey paper based on the literature review and empirical analysis is designed, distributed and collected. Some influential and necessary essentials of the LCA reports for the decision makers are picked out and summarized in accordance with the results of survey papers. This thesis concludes by presenting a new map of LCA reports and suggestions for further research.

Yes / There is general agreement on the importance of green roofs as ways of reducing GHG emissions, reducing overall costs and improving sustainability in urban areas. This systematic literature review highlights life cycle sustainability assessment as an essential criterion to evaluate green roofs. A bibliometric analysis was used to quantitatively review relevant literature. The Scopus database was chosen as a bibliographic database of academic publications. Thes period of search started from 2003 and final search was conducted on February 15, 2023. Based on further in-depth reading, 88 publication records which met the selection criteria, including 74 papers and 14 conference papers. Researchers from the United States contributed almost 31 % of the documents. We evaluated leading studies in this field and discussed assessment method, system boundaries and research gaps through a critical literature review and a systematic search review. Finally, we propose a framework and identify a gap and future research. The environmental aspect of green roofs have received more attention than economic issues. We found that most economic evaluations of green roofs are limited to their construction stage. As yet there is no comprehensive social study on green roofs. We considered a unified study of the economic, environmental impact and social evaluation of green roofs to be warranted. Additionally, various measurement methods should be used to assess the economic profitability of green roofs over the long term. In summary, this study provides a deeper understanding of the environmental, social, and economic performance of green roofs and identifies research gaps as well as future research directions.

Yes / There is general agreement on the importance of green roofs as ways of reducing GHG emissions, reducing overall costs and improving sustainability in urban areas. This systematic literature review highlights life cycle sustainability assessment as an essential criterion to evaluate green roofs. A bibliometric analysis was used to quantitatively review relevant literature. The Scopus database was chosen as a bibliographic database of academic publications. Thes period of search started from 2003 and final search was conducted on February 15, 2023. Based on further in-depth reading, 88 publication records which met the selection criteria, including 74 papers and 14 conference papers. Researchers from the United States contributed almost 31 % of the documents. We evaluated leading studies in this field and discussed assessment method, system boundaries and research gaps through a critical literature review and a systematic search review. Finally, we propose a framework and identify a gap and future research. The environmental aspect of green roofs have received more attention than economic issues. We found that most economic evaluations of green roofs are limited to their construction stage. As yet there is no comprehensive social study on green roofs. We considered a unified study of the economic, environmental impact and social evaluation of green roofs to be warranted. Additionally, various measurement methods should be used to assess the economic profitability of green roofs over the long term. In summary, this study provides a deeper understanding of the environmental, social, and economic performance of green roofs and identifies research gaps as well as future research directions.

The extensive use of nanoparticles (NPs) has started receiving increased attention because of the knowledge gaps regarding their fate in the environment and the possible impact on the environment and human health. The production of silver nanoparticles (AgNPs) and titanium dioxide nanoparticles (TiO2-NPs) is increasing and it is expected that, due to their great number of applications, their concentration in waste streams will increase in the future. The presence of NPs in waste streams may affect the treatment process (e.g., composting) and, if they are not successfully removed from the waste streams, their presence in the treated waste (e.g., compost) may present an environmental risk. Composting of the biodegradable fractions of municipal solid waste (MSW) is a widely used waste management practice, mainly because it is a cost-effective treatment technology and the final product (i.e., compost) presents several benefits to the environment, particularly as a soil conditioner. The overall aim of this thesis is to assess the effect of Ag-TiO2NPs and AgNPs that may be present in the biodegradable fractions of municipal solid waste on composting and subsequent soil application of compost. For that purpose in-vessel composting of artificial municipal solid waste contaminated with commercial nanoparticles was investigated at laboratory scale, simulating a range of relevant concentration levels. Subsequently, the fate of NPs present in mature compost use as a top-layer soil conditioner was investigated using a column approach at laboratory scale. The toxicity effect of NPs present mature compost on plant growth was further investigated. The impact of NPs during composting was assessed by monitoring the temporal dynamics of organic matter (OM) using Excitation Emission Matrix (EEM) fluorescence spectroscopy. The fate of NPs following application of contaminated mature compost as a top-soil conditioner and potential release to groundwater was investigated using a column leaching experiment while the phytotoxicity of mature compost contaminated with NPs was assessed using a seed germination bioassay. Finally, to investigate further possible environmental impacts due to the application of mature compost contaminated with NPs to soils, a Life Cycle Assessment (LCA) was conducted. The impact of commercial Ag-TiO2 NPs and AgNPs on the in-vessel composting of biodegradable municipal solid waste was investigated over 21 days, using initial concentrations of 0, 5, 10, 20 and 50 mg Ag / kg of OM. Microbial activity was inhibited in the biodegradable waste reactors using 2% NaN3 to evaluate abiotic losses. Physicochemical parameters such as pH, ash content, weight loss, and the formation of humic substances (HS) were determined after 0, 4, 7, 14 and 21 days of composting and after a maturation phase. The results indicated that the presence of 2% NaN3 in biodegradable MSW inhibited effectively the microbial activity during the first week of composting. The microbial population was activated during the second week of composting but the decomposition rate was so low that did not result in the formation of humic substances (HS) following 21 days of composting when 2% NaN3 was used. Both treatments, using Ag-TiO2-NPs and AgNPs, did not show any inhibition of the decomposition process for all the tested concentrations and EEM peaks shifted towards the HS region during in-vessel composting. Higher inorganic carbon removal resulted from NP-contaminated compost with higher NP concentrations. This may indicate that the formation of humins was higher for non-contaminated compost and decreased as the NP concentration in waste increased. The shift of the peaks towards the HS region during composting for all the treatments suggested that NPs did not have an effect on humification and therefore on compost stability. The leaching properties of the NP-contaminated compost were investigated using a column leaching test. Five samples of leachate, of 50 mL each, were collected. The highest concentrations of HS were observed in the first two leaching samples. The leaching results suggested that only a low percentage of the total NPs (in weight) in compost, up to ca. 5% for Ag and up to ca. 15% for Ti, leached out from the columns, which was assumed the amount that potentially could leach to the environment. These results suggested that NPs will mainly accumulate in soils’ top layers following application of compost contaminated with NP. The phytotoxicity of NP-contaminated compost was assessed using a seed germination bioassay and the germination index was then calculated. The results indicated that the NP-contaminated compost did not present any toxic effects to cress germination. The possible environmental impacts due to the NP-contaminated compost application to soils were investigated by conducting a comparative LCA study. The LCA study indicated that the effects of NP-contaminated compost to human health and ecosystems endpoint categories increased due to the presence of NPs. The risks are associated with terrestrial ecotoxicity and human toxicity midpoint categories and are mainly attributed to the accumulation of Ag to soils.

The aim of this Engineering Doctorate is to design, build and test novel environmental retrofit technologies to reduce energy consumption in existing buildings. Three contributions to knowledge are documented. The first contribution is the technical verification of a novel proof-of-principle prototype incorporating translucent silica aerogel granules to improve the thermal performance of existing windows without blocking out all of the useful natural light. The study demonstrates that a 10 mm thick prototype panel can reduce heat loss by 80 %, without detrimental reductions in light transmission. Payback periods of 3.5-9.5 years are predicted if applied as openable shutters or removable secondary glazing. The second contribution is a streamlined life cycle assessment of silica aerogel following the ISO 14000 standards. The study assesses the raw materials and electricity use associated with two of the three known methods of aerogel production. Despite being produced in a laboratory that had not been refined for mass manufacture, the production energy and CO2 burden from aerogel production can be recovered within 0-2 years when applied in a glazing application. The third contribution is the development and verification of a novel solar air heater incorporating granular aerogel, retrofitted to an external south facing wall, preheating the air in a mechanical ventilation system with heat recovery on a hard4to4 treat domestic property. During the 7-day in-situ test, peak outlet temperatures up to 45 °C were observed and validated to within 5 % of predictions, preheating the dwelling’s fresh air supply up to 30 °C, facilitating internal temperatures of 21-22 °C without auxiliary heating. The predicted financial and CO2 payback for a range of cover thicknesses is 7-13 years and 0-1 years, respectively. Efficiency up to 60 % and a financial payback of 4.5 years is predicted with an optimised design incorporating a 10 mm thick granular aerogel cover.

The food production system has been acknowledged as a problem that needs to be addressed in order to achieve a sustainable society. Hertwich and Peters (2009), estimate that 10-30% of an individual’s environmental impact is related to the industrial production and consumption of food. The problem is aggravated by the wastage of one third of the global food production. The consequences of the wastage of food are the loss of resources, such as energy, water, land and labour and unnecessary emissions of pollutants. In order to address this problem several actions have been proposed. The Sustainable Development Goal 12.3, which Sweden has committed to fulfil, aims to reduce by half the amount of food waste along the production and supply chain by 2030. Retail is an important player in the food supply chain. Its influence spreads both upstream to suppliers and downstream to consumers. Therefore, this research aims to contribute to reduction of the environmental impacts related to food waste in retail, by identifying products with high environmental impacts. The main goals of this study are 1) the quantification of food waste produced by the supermarket and 2) to examine the environmental impacts of selected products in order to assess the impacts generated by the waste production at the supermarket. The findings of the research revealed 1) the importance of not only measuring the food waste in terms of mass, but also in terms of environmental indicators and costs. The results indicate bread as an important contributor for the environmental footprint of the supermarket and a potential product for interventions 2) Sorting the organic content of the products from its packaging before sending it to the current waste treatment leads to a reduction in the carbon footprint. The research identified the following recommendations: 1) increasing supermarket personnel and consumers’ awareness regarding the environmental impact of food waste, 2) finding alternative routes for waste treatment and 3) improving logistic operations.

The UK domestic building sector accounts for a substantial amount of the final energy demand and greenhouse gas (GHG) emissions. To this extent, the sector can play an important role in GHG abatement and energy demand reduction, essential objectives of a more ‘sustainable energy system’. Microgeneration, or production of electricity or heat from small-scale sources, have been advocated by some, including the Supergen ‘Highly Distributed Power Systems Consortium’ to which this thesis contributes, as important means towards achieving these objectives. In this thesis, three assessed microgenerators; specifically a 600W microwind system, 2.1 kWp photovoltaic (PV) and building-integrated photovoltaic (BIPV) systems, and a 2.8m2 solar hot water (SHW) system have been analysed through an ‘integrated appraisal toolkit’ in order to assess their respective economic and financial performance in current UK context. A cost-benefit analysis (CBA) is applied, based on outputs and results from energy analysis and life-cycle assessment (LCA), and other tools such as financial appraisal, cost-effective analysis (CEA), and simple multi-attribute ranking technique (SMART) are also performed in order to asses how these systems perform on an individual household level or when compared to other energy technologies. The CBA, which included environmental impacts quantified through the LCA, obtained negative net present values (NPVs) for all the assessed microgenerators with the exception of microwind in a high-wind resourced ‘open’ area with lower end capital costs. The NPVs in the financial appraisal, which excluded environmental impacts, yielded relatively poorer results still. Only with the proposed feed-in tariffs would the systems all achieve positive NPVs. Given that the CBA included a substantial qualitative part, alternative tools, such as CEA and multi-criteria evaluation were applied (in brief) in order to place the assessed systems in the context of other energy generating sources in the UK, and to enable a more confident decision with respect to whether these systems should be advocated or rejected.

Concerns over environmental impacts and long term availability of liquid fossil fuels means that sourcing alternative, renewable transport fuels has increased in importance. To date, implemented approaches have concentrated on the production of liquid biofuels biodiesel and bioethanol from crops. Even though technology for implementation is readily available in the form of biogas production and upgrading, gaseous fuels have been largely overlooked in the UK. Research completed showed that if produced from indigenous crops using currently viable technology, it is energetically more favourable to produce gaseous fuels rather than biodiesel or bioethanol with gaseous fuels also delivering some emission benefits at end use. To date, the subsidy system supporting biofuel production has not functioned well. Research showed that if the subsidies approached the maximum allowable value, and when produced from waste materials, the production of gaseous fuels can be economic compared to liquid biofuels. Life cycle assessment has showed that utilising biomethane as a vehicle fuel could be an environmentally appropriate approach if the conventional use for biogas of combusting in a combined heat and power plant cannot utilise the majority of the excess heat produced. A two stage process to produce a hydrogen / methane blend was shown to be energetically favourable when utilising wheat feed, although hydrogen production was low. The process was not energetically favourable when food waste was utilised, indicating the importance of optimising process according to feedstock characteristics. Life cycle assessment of electrolytic hydrogen production using a range of energy sources found that electrolysis driven by renewable energy was a valid option for future deployment. However, given current feedstock availability, indigenous biofuel production, regardless of the fuel produced, could only make minor contributions to overall fuel requirements. As such, a range of fuel vectors, or a significantly greater commitment of land resources to fuel production, will be required in the future.

Life Cycle Assessment (LCA) has been successfully used as an environmental assessment tool for the development of ecologically sustainable products. The application of LCA in the early design stage has been constrained by the requirement of large amounts of data and time for carrying out the assessment. In addition, the complexity of LCA causes further difficulties for product developers. In order to integrate the environmental assessment into the process of product development, this research proposes an integrated decision model for sustainable product development and a simplified LCA approach for the application in the early stage of product design. The main advantage of the proposed model is that it incorporates the environmental aspects of product development into the existing product development framework. It enables designers to strike a balance between the product???s environmental performance and other traditional design objectives. The simplified LCA approach is based on the concept and application of Environmental Impact Drivers. Material-based environmental impacts and Energy-based environmental impacts are used to predict the total environmental impact of a product. Two sets of impact drivers were developed accordingly. The Material-based Impact Drivers were identified by classifying materials into 16 groups according to the nature of the materials and their environmental performance. Energy-based Impact Drivers were developed for various energy sources in major industrial regions. Product LCA cases were used to verify the proposed methods. The results computed by the application of the impact drivers were compared with the results of full LCA studies. It is concluded that with the proposed approach, the product???s environmental performance can be assessed in a very short time and with very basic data input requirements and acceptable accuracy.

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