Environmental Research Institute - Doctoral Theses

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    Sustainability assessment of the repurposing of wind turbine blades
    (University College Cork, 2022) Nagle, Angela J.; Leahy, Paul; Dunphy, Niall; Mullally, Gerard; Science Foundation Ireland
    Ireland is regarded as rich in wind resources, with Wind Energy Ireland suggesting that wind generation could make Ireland a renewable superpower. Ireland has chosen to capitalise on this resource by dramatically expanding wind energy generation capacity. However, with this development of wind capacity comes the need to deal with increasing amounts of waste from the wind sector when the turbines reach end-of-life. While much of the turbine is recyclable, the blades, which are made from composite glass fibre and polymer material, is not yet economically viable to recycle. Many blades are being landfilled or incinerated at the end of their working lives. An option that is gaining in popularity is the idea of repurposing blades into useful structures. This thesis considered the question “Can repurposing of end-of-life wind turbine blades from Irish wind turbines offer overall gains in sustainability?” Overall sustainability was by developing a Life Cycle Sustainability Assessment framework, which includes environmental Life Cycle Assessment (LCA), Life Cycle Costing (LCC) and the lesser established social life cycle assessment (s-LCA). LCA was used to first establish co-processing of the discarded blade material in Ireland as the most likely and best case scenario against which to compare repurposing solutions. Three overall scenarios were then developed based on maximizing blade consumption, the substitution of high embodied carbon materials, and serving customer segments who will benefit from circular material use such as the county councils who may be required to adhere to Green Public Procurement requirements. Based on these scenarios and customer segments, an estimated 20% of the blade material estimated to be decommissioned in Ireland could potentially be repurposed, offering reductions of 30,780 kg CO2 equivalents of emissions per year. The concept of using end-of-life blades to make bridges (termed ‘BladeBridge’) was selected from the scenarios for an in depth study. LCA and LCC comparisons against a conventional bridge and the baseline disposal method, showed BladeBridge to be environmentally less impactful than both of these scenarios. From a cost perspective, the first BladeBridge using a specific blade model will be slightly more expensive than a conventional bridge and subsequent blade bridges due to the reverse engineering required to assess the residual structural properties of the blade. However, second and subsequent bridges made from the same blade models would be less expensive. Indicators for s-LCA were developed by considering national shortfalls in Ireland’s performance against the Sustainable Development Goals (SDGs), which can be considered the world’s key performance indicators. In this way, these indicators capture a product’s ability to affect global social indicators in which Ireland most needs to improve upon. Using LCA, LCC and the SDG based s-LCA indicators, a stage/gate screening process was developed which follows the embedded systems model of sustainability. In this framework, early business ideas can be first screened for environmental and social value, and then for cost viability. This framework can help in the development of ‘purpose driven businesses.’ The research presented in this thesis combined life cycle thinking with policy considerations and business value creation, and offers contributions across all of these areas. Some examples of contributions are the positioning of LCA in the repurposing debate; the creation of a framework for life cycle assessments of products made from end-of-life material that can be used to contribute to improving globally defined social and environmental metrics; analytical tools for local authorities to implement green public procurement; and support for Ireland to decouple its renewable energy generation from the production of waste.
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    How seabirds respond to a changing oceanic environment: a biologging approach
    (University College Cork, 2023-05-17) Darby, Jamie; Jessopp, Mark John; Quinn, John; Irish Research Council; Petroleum Infrastructure Program
    Marine habitats are undergoing rapid change due to human influences. The intensity and diversity of human impacts on oceanic habitats are increasing with rising demand for energy and resources. For example, fisheries operate in over 90% of the ocean, harvesting marine life and directly affecting ecosystem functions and resilience. Climate change is also changing the physical and chemical properties of the ocean and altering storm frequency and intensity at a global scale. Seabirds are a group of marine predators that are sensitive to such changes, with impacts contributing to global population declines. We broadly understand how stressors affect different species through effects on life histories and physiological traits, and where seabirds are most impacted based on spatiotemporal overlap of seabirds with human activities. However, finer scale behavioural data are required to understand the functional response of seabirds to different stressors. Biologging devices are continuously improving and miniaturising, being applied to collect fine-scale behavioural information for smaller species and for more protracted durations. In this thesis, biotelemetry is used to investigate the at-sea behaviour of three North Atlantic seabird species in order to understand the drivers of distribution. A better understanding of such drivers sheds light on the challenges facing seabird species when far from land, susceptibility to stressors, and provides insights into more effective monitoring and conservation efforts. Chapter 1 provides a broad introduction to seabird ecology, the application of biologging, and identifies model species for investigating seabird responses to a range of environmental stressors. Chapter 2 investigates the diving behaviour of Manx shearwaters (Puffinus puffinus) and how this correlates with water clarity, which is predicted to deteriorate with increasing urbanisation, eutrophication, and climate impacts. Chapter 3 highlights the relative importance of commercial fisheries compared to other environmental variables in driving the foraging distribution and behaviour of northern fulmars (Fulmarus glacialis) during the breeding season. Chapter 4 expands on this by identifying fulmar-vessel encounters in the non-breeding season, showing how nocturnal vessel attendance is increasing over time, and the apparent relationship with migration effort and time-activity budgets. Chapter 5 identifies unusual levels of variability in the moult period of Atlantic puffins (Fratercula arctica), when they are flightless and more susceptible to climate impacts that may prevent them from foraging. Variability in moult strategy is tied to susceptibility of populations to risks posed by severe winter storms. Chapter 6 provides a synthesis of findings from previous chapters, highlighting how the methods and principles developed may be built upon to further improve our knowledge of seabird ecology and design appropriate conservation measures. Building on insights from previous chapters, I discuss how seabirds are likely to functionally respond to several stressors in the marine environment, including fisheries practices, climate change, and shifting prey availability. Several recommendations are made for further research, including exploring mitigative measures that can be employed to tackle the negative effects of changes to their environment.
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    Synthesis of nanomaterials for applications in heterogeneous catalysis
    (University College Cork, 2022-12-20) Casey, Éadaoin; g.collins@ucc.ie; Holmes, Justin; Science Foundation Ireland
    The purpose of this thesis was to synthesise nanomaterials with a variety of chemical and physical properties to find the optimum design of heterogeneous catalysts for a variety of applications in heterogeneous catalysis. The aim for chapter 3 was to synthesise support free Pd NPs which are stabilised by a range of small organic ligands and polymers for the application in the pharmaceutical synthesis. It was vital to identify the correct capping ligand to stabilise the NP to find the optimal catalyst for the reductive amination reaction. A range of material characterisation methods were used to evaluate the impact of ligands and the role of steric and electronic effects on the selectivity behaviour of the Pd NPs when they were stabilised by different capping ligands which helped identify the best catalytic system. PVP stabilised Pd NPs was found to be the best performing catalyst displaying the best overall yield of the desired product. XPS and FTIR revealed that the presence of PVP ligands at the NP surface gives rise to combination of steric and electronic effects and it was shown that electron donation from the PVP carbonyl group to the Pd NP occurred. Chapter 4 focused on plasmonic photocatalysis which allows harvesting of visible light as an abundant and renewable energy source to drive a myriad of chemical reactions. The novelty of this work is that it combines a two- dimensional (2D) metal catalyst and plasmonic photocatalysis which has not been reported in literature. The high proportion of exposed surface atoms and large surface area of ultrathin 2D nanosheets results in high atom efficiency. Light-harvesting catalysts allow lower reaction temperatures and enhanced reaction rates, enabling more energy efficient and greener routes to chemical synthesis. The chapter developed a new synthesis method for 2D alloyed PdAu nanosheets using long chain surfactants to template the growth. Tuning the surface chemistry was critical to controlling the two-dimensional growth and maintaining high catalytic activity. The catalysts display outstanding activity for visible-light driven room-temperature Suzuki cross coupling reactions, greatly outperforming commercial Pd catalysts. The need for the development of efficient catalysts for the chemical recycling of PET to tackle the global issue of plastic waste was the motivation of Chapter 5. Designing the optimum heterogenous catalyst was the main aim of this work with particular focus on immobilisation of metal ion and nanoparticle based catalysts. Surface modification of a catalyst support with organic linkers is a suitable strategy to immobilise transition metal ions onto a SiO2 support material. The nature of the organic ligand being connected to the ion influences the steric and electronic effects which influences the catalytic behaviour. The NP catalysts were found to be superior than the ion immobilsed catalysts in the degradation of PET to its monomer BHET, due to synergistic effects between the NP and the organic ligand. The aim for chapter 6 was to find the optimum metal free heterogeneous catalyst anchored on SiO2 support. This work was inspired by the findings in chapter 5. Three guanidine catalyst with a range of nitrogen environments were synthesised as potential metal free catalysts for the degradation of PET and PLA. The catalysts were evaluated under conventional, and microwave assisted heating methods to find the best method for converting these plastics to their monomers with high yields. The catalysts were evaluated using material characterisation methods such as XPS, TEM and FTIR. It was discovered that the best performing catalyst had the most nitrogen environments eluding that the nitrogen availability was an important feature for the catalyst activity for both PET and PLA degradation. Microwave assisted heating methods outperformed the conventional heating methods yielding high conversions with less energy and time being required.
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    Spatiotemporal modelling of antimicrobial resistance in the Irish subsurface environment
    (University College Cork, 2023-01-31) Albuquerque de Andrade, Luisa; O'Dwyer, Jean; Weatherill, John; Hynds, Paul; Science Foundation Ireland; Geological Survey of Ireland
    Antimicrobial resistance represents a significant public health risk, with global estimates indicating that as many as 1.27 million deaths were directly attributable to antimicrobial resistant infections in 2019. The adverse human health effects attributed to the continuous rapid spread of antimicrobial resistance are particularly pressing in the aftermath of the COVID-19 pandemic, which highlighted societies’ acute susceptibility to infectious diseases in the absence of effective treatment options. The proliferation of antimicrobial resistant bacteria (ARB) was also acknowledged as the key emerging issue of environmental concern by the United Nations Environmental Programme in 2017. Despite this, the natural environment’s role in the spread of ARB-related infections remains unclear. In this context, ARB presence in groundwater resources represents a noteworthy concern, as these can act as prospective reservoirs, while offering a direct exposure route to the over 2.2 billion groundwater consumers worldwide. In the Republic of Ireland (RoI), private groundwater wells supply approximately 11% of the population, with these users already associated with increased incidence rates of waterborne infections. Indeed, Irish private wells have been linked to persistent microbiological contamination attributable to inadequate on-site domestic wastewater treatment systems and the widespread agricultural activities associated with the Irish rural landscape; both of which are also potential sources of ARB. Thus, and in combination with a diverse (hydro)geological profile and a temperate climate characterised by the absence of a dry season, the RoI may present the ‘perfect storm’ for groundwater contamination by ARB and subsequent adverse human health effects. To-date, however, just one spatiotemporally limited study exists which investigates this issue within the RoI, leading to significant knowledge gaps regarding the spatial and temporal dynamics of ARB contamination in Irish groundwater environments. Accordingly, the current research blends systematic literature review and pooled analyses, traditional hydrogeological fieldwork, geo-referencing, molecular microbiology, analytical chemistry, genome sequencing, and statistical modelling to quantify occurrence rates and elucidate the potential drivers of ARB contamination in groundwater resources. The overarching aim of this research is to better understand ARB presence in Irish groundwater supplies and inform appropriate source-protection strategies, in line with Sustainable Development Goals 3 ("good health and well-being") and 6 ("clean water and sanitation for all”). Research findings indicate that groundwater resources may represent a global reservoir/pathway for ARB, with 80.2% ± 29.0 of groundwater-derived bacteria from studies in the systematic review exhibiting resistance/intermediate resistance to at least one antimicrobial. In the RoI specifically, the analyses of monitoring data from a 10-year period showed Escherichia coli contamination in 66.7% of monitored (regulated) water supplies nationwide at least once, with pastoral agriculture (a well-known potential source of ARB in addition to faecal bacteria contamination) identified as a key risk factor. Additionally, fieldwork data identified antimicrobial resistance in 16.7% of Escherichia coli (8/48) but none of the Pseudomonas aeruginosa (0/6) collected from 132 geographically dispersed (unregulated) private wells in the RoI sampled during autumn 2019 and summer 2021. Fieldwork results also revealed that the presence of resistant E. coli was significantly associated with increased local cattle density (OR = 1.028; p = 0.037), having likely been transported into wells via surface run-off followed by direct wellhead ingress. Moreover, lack of statistical significance (p ≥ 0.084) between overarchingly low concentrations of co-selective (i.e., metal/metalloid) parameters and antimicrobial resistance gene abundance in E. coli isolates lead to the hypothesis that E. coli may have acquired resistance prior to entering these groundwater supply environments. With that, findings suggest contamination of rural groundwater resources with ARB in the RoI as being highly preventable by ensuring appropriate source protection measures. Research results bridge the gap between hydrology, geoscience, and heath, promote capacity building, and inform the development of effective policy for groundwater management and antimicrobial resistance action plans into the future.
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    Improving the ability of energy systems optimisation modelling to inform national energy policymaking
    (University College Cork, 2023-04-27) Aryanpur, Vahid; O'Gallachoir, Brian; Glynn, James; Daly, Hannah E.; Science Foundation Ireland
    Energy Systems Optimisation Models (ESOMs) are extensively used to inform energy and environmental policymaking. They generate valuable insights into the possible pathways that reduce our reliance on fossil fuels and achieve ambitious clean energy transition goals. However, the academic literature identifies a number of priority areas for development with ESOMs to improve their ability to generate useful insights applicable to the energy transition. This thesis explores and delivers key developments in several of these dimensions: spatial resolution, energy-economy linkage, significance of model skill, and heterogeneity of consumers. From a policy perspective, this thesis seeks to improve the model-based analysis in the context of national-level energy sector decarbonisation and thus, mitigation policies are critically investigated. Moreover, the impacts of the mitigation actions on local air pollution levels and promoting energy security are also explored. Accordingly, the main contributions of this thesis are improvements to the state-of-the-art energy modelling methods and applications of the enhanced models to answer key policy questions with convincing evidence. The improvements are demonstrated via two well-established energy systems modelling tools in Ireland and Iran. The thesis concludes with several modelling and policy insights and suggestions on interesting areas for further investigation to strengthen the contribution of ESOMs to ensure improved climate mitigation and energy policies. The first weakness is the limited spatial and consumer granularity in ESOMs which constrains their ability to analyse region-specific energy transition pathways. This thesis develops a multi-regional representation of the transport sector within the TIMES-Ireland Model (TIM), an ESOM used to develop ambitious mitigation pathways for Ireland’s energy system. The multi-regional approach captures region-specific characteristics of transport technologies and infrastructures across 26 counties. It also incorporates the heterogeneity of the impact of air pollution in sub-national regions and estimates the ancillary pollution benefits of the mitigation targets in those regions. The spatially explicit modelling approach also reveals higher economic co-benefits than single region modelling. The single-region method masks the higher damage costs in medium and large cities, thus underestimating total benefits. This thesis also develops a multi-consumer approach, more accurately capturing consumer heterogeneity. Having homogeneous consumers in ESOMs tends to oversimplify purchase decisions, especially for capital-intensive technology adoption. TIM simulates vehicle purchase decisions using hurdle rates. This thesis disaggregates consumers into five groups, ranging from low- to high-income families, to incorporate a more realistic representation of their behaviour in vehicle purchasing decisions. The results demonstrates that the model with heterogenous consumers offers higher Electric Vehicle (EV) adoption than a single region model calibrated with average national data and identical consumers. Spatially explicit analysis presents valuable insights into regional EVs diffusion and their electricity consumption at a subnational level which are usually challenging to achieve through an aggregated national model. Secondly, ESOMs often ignore the effects of changes in energy costs on energy service demands, despite their key ability to balance supply and demand. The thesis addresses this by developing a comprehensive representation of the power sector within the MESSAGE model, an ESOM used to explore the impacts of different subsidy reform scenarios in Iran. The thesis develops a soft-linked framework combining MESSAGE with an economic model and analyses both supply and demand sides under harmonised assumptions. The novel soft-linking addresses the structural weakness of ESOMs in capturing the effects of energy price on demand. The hybrid model is used to investigate the impacts of subsidy removal on power demand and the required generation mix. The findings reveal that under an early and steady reform scenario, the system avoids lock-in effect, and thus the development of renewable energy technologies and energy efficiency plans become cost-competitive. By contrast, the late subsidy reform path even with radical removal fails to tackle the lock-in effect’s risk. On the other hand, the long-term energy system transition is deeply uncertain. The hybrid modelling framework in this research is also used to conduct an ex-post analysis exploring the extent to which electricity subsidy reform could have reduced Iran’s energy demand during the last three decades. To minimise the uncertainties, both energy and economic models are calibrated with three decades of historical data. The cost-optimal modelling results are then compared with the real-world transition, revealing a 50% lower cumulative cost in the subsidy removal scenario compared with the real-world transition. This deviation highlights what could have been achieved through the implementation of different policies in the absence of uncertainties, providing valuable insights for informing future policy initiatives. Finally, this hybrid framework is also used to show how synergies and efficiencies from Iran’s energy subsidy reforms and lifting its sanctions could enhance global energy security, with a focus on natural gas. It demonstrates that significant opportunities could be realised through a combination of national energy policy reforms and cross border cooperation in a favourable international environment.