Embedding Circular Economy Principles into Urban Regeneration and Waste Management: Framework and Metrics

In a highly urbanised world, cities have become main centers of resource consumption and generation of waste. The notion of the circular economy (CE) identifies strategies for slowing and narrowing resource use through the prevention of waste, improvement of resource use, and substitution of the use of primary resources with recovered materials (and energy). The literature has recently started to explore the concept of circular cities, and a number of cities around the globe have adopted circular economy strategies. Urban regeneration can play a critical role in enabling more circular loops of resources and contribute to more sustainable urban environments; however, there is a lack of contributions in the literature that explore the circularity of urban regeneration projects. The aim of this research is to address this gap by providing a framework and metrics to embed circular economy principles into urban regeneration. The proposed framework and set of metrics are then applied to a case study in West London to quantitatively assess CE implications and point to opportunities to increase circularity. Three main scenarios are developed to assess resource impacts of different waste strategies. The maximizing recycling scenario suggests that over 65% recycling and just under 35% energy recovery could be achieved for the area. However, findings suggest potential trade-offs between strategies centered around energy recovery from waste and strategies that prioritise recycling of recyclable fractions from waste. The three scenarios are then assessed against the CE metrics proposed. Again, here, ‘maximising recycling’ better aligns with the proposed CE metrics and contributes to cutting around 50% of GHG emissions associated with management/disposal of residual waste while increasing opportunities for resource recovery. Finally, some conclusions are drawn pointing to pathways to maximise optimal resource use and infrastructural provision in urban regeneration

Life Cycle Assessment of a novel digestate treatment unit for anaerobic digestate plant: a UK case

Management of digestate co-product produced from anaerobic digestion (AD) has become a challenge due to impacts on the environment. Valorising AD into high-value products is not only considered as a solution to this issue but can also make AD more cost-effective. Project NOMAD (Novel Organic recovery using Mobile ADvanced technology) funded by H2020 is currently developing an innovative solution for valorising digestate. A designed mobile unit combines several digestate treatment technologies, i.e., solid-liquid separation, ultraviolet light and ozone oxidation, and electrodialysis. The valuable nutrients are concentrated from the liquid fraction, and the solid fraction is collected as compost. This study adopts Life Cycle Assessment (LCA) methodology to assess environmental impacts of the NOMAD unit incorporated into a UK AD plant, focusing on business-as-usual (BAU) case, NOMAD scenario, and upscaled NOMAD scenario. The BAU case is current management of digestate, where digestate is transported, stored, and applied to farmlands. The NOMAD scenario introduces one unit, capable of addressing digestate 5 ton/day, while the upscaled NOMAD scenario can process all digestate produced from the AD plant. 12 impact categories are selected using ReCiPe 2016. The results show that the upscaled NOMAD scenario can reduce 11%-69% of targeted impacts compared to BAU scenario, with 1%-24% reduction for NOMAD scenario. The NOMAD unit process, either upscaled or one-unit, contributes less than 6% of overall impacts, while AD activities and field application are the main impact contributors. The outcome of these scenarios validates the NOMAD unit for valorisation of digestate from environmental impact perspective

Life Cycle Assessment of baby leaf spinach: Reduction of waste through interventions in growing treatments and packaging

Food production, distribution and waste impact significantly on the environment, with recognised contributions to GHG emissions and Global Warming Potential (GWP) at each stage of the supply chain. Fresh leaf vegetables, such as salad leaves and spinach, are particularly prone to spoilage and efforts are being made to reduce waste, by increasing shelf-life through growing treatments and packaging choices. This presentation reports on the findings of Life Cycle Assessment studies carried out to support the Science Foundation Ireland (SFI) funded project ‘Leaf no Waste’ (Grant: 20/FIP/FD/8934). The study looks at the production of baby leaf spinach grown in Ireland and explores changes in the environmental impacts profile (e.g. GWP) for a foliar silicon treatment and two packaging options (i.e. Oriented Polypropylene (OPP) and Polylactide (PLA)). The system boundary of the study includes the field production of spinach, storage, packaging, retail, and waste management options, for the functional unit 1 kg packed baby leaf spinach. 4 scenarios were selected from the experimental data, namely spinach packed in OPP, spinach packed in PLA, silicon treated spinach in OPP, and silicon treated spinach in PLA. Furthermore, waste at 3-day shelf-life and waste at 7-day shelf-life were compared, to evaluate the effects of the treatments, and the resulting environmental impacts based on the LCA . The preliminary results illustrate that the storage and packaging process and retail stage are among the key contributors to GWP due to packaging material production and energy use. Comparison of scenarios under 3-day shelf life shows that spinach with PLA packaging is worse than that with OPP packaging in both base case and silicon treatment scenarios. However, application of silicon product shows potential to benefit the spinach supply chain with PLA packaging, while it has little effect on OPP packaging cases

Global Environmental Engineering for and with Historically Marginalized Communities

Marginalized communities lack full participation in social, economic, and political life, and they disproportionately bear the burden of environmental and health risks. This special issue of Environmental Engineering Science, the official journal of the Association of Environmental Engineering and Science Professors (AEESP), reports research on the unique environmental challenges faced by historically marginalized communities around the world. The results of community-based participatory research with an Afro-descendant community in Columbia, Native American communities in Alaska, United States, villagers in the Philippines, disadvantaged communities in California, United States, rural communities in Mexico and Costa Rica, homeless encampments in the San Diego River (United States) watershed entrepreneurs in Durban, South Africa, and remote communities in the island nation of Fiji are presented. The research reported in this special issue is transdisciplinary, bringing engineers together with anthropologists, sociologists, economists, and public health experts. In the 13 articles in this special issue, some of the topics covered include inexpensive technologies for water treatment, novel agricultural strategies for reversing biodiversity losses, and strategies for climate change adaptation. In addition, one article covered educational strategies for teaching ethics to prepare students for humanitarian engineering, including topics of poverty, sustainability, social justice, and engineering decisions under uncertainty. Finally, an article presented ways that environmental engineering professors can engage and promote the success of underrepresented minority students and enable faculty engaged in community-based participatory research

Regionalized strategies for food loss and waste management in Spain under a Life Cycle thinking approach

Food loss and waste (FLW) has become a central concern in the social and political debate. Simultaneously, using FLW as a bioenergy source could significantly contribute to closing the carbon cycle by reintroducing energy into the food supply chain. This study aims to identify best strategies for FLW management in each of the 17 regions in Spain, through the application of a Life Cycle Assessment. To this end, an evaluation of the environmental performance over time between 2015 and 2040 of five di erent FLW management scenarios implemented in a framework of (i) compliance and (ii) non-compliance with the targets of the Paris Agreement was performed. Results revealed savings in the consumption of abiotic resources in those regions in which thermal treatment has a strong presence, although their greenhouse gas (GHG) emissions in a scenario of compliance with climate change targets are higher. In contrast, scenarios that include anaerobic digestion and, to a lesser extent those applying aerobic composting, present lower impacts, including climate change, suggesting improvements of 20-60% in non-compliance and 20-80% in compliance with Paris Agreement targets, compared to the current scenarios.This research was funded by the Spanish Ministry of Science and Competitiveness, grant number CERES-PROCON Project CTM2016-76176 (AEI/FEDER, UE) and KAIROS-BIOCIR Project PID2019-104925RB (AEO/FEDER, UE)

What do changing weather and climate shocks and stresses mean for the UK food system?

In light of the publication of Henry Dimbleby’s National Food Strategy (www.nationalfoodstrategy. org/) and the COP26 climate meeting in Glasgow, it is timely to consider the impacts of weather and climate extremes on the UK food system. Climate change-driven changes in extreme weather events are one of the highest-risk future shocks to the UK food system [1], underlining the importance of preparedness across the food chain [2]. Here, we identify major knowledge gaps in the primary impacts of extreme weather and climate change across the UK’s food system, its functioning and their interactions to provide information to support adaptation and resilience planning. Research tends to focus on individual food system activities rather than taking a systematic approach [3, 4]. How- ever, strong evidence exists about the impacts of long- term climate trends and extremes [5] on primary food production [6]. The major knowledge gaps therefore concern post-primary production dimensions [4], notably food system activities between the ‘farm-gate’ and consumption—which are the core focus of this paper (supplementary material S1 available online at stacks.iop.org/ERL/17/051001/mmedia). These constitute major economic and social dimensions but are often the ‘missing middle’ in food system discus- sions. We use the UK food system as an illustrative case study, and consider both global and domestic risks and implications. We present methods, tools and frameworks for systemic analysis of climate impacts on food systems, consider the funding landscape, and highlight priorities for future research

Challenge clusters facing LCA in environmental decision-making—what we can learn from biofuels

Purpose Bioenergy is increasingly used to help meet greenhouse gas (GHG) and renewable energy targets. However, bioenergy’s sustainability has been questioned, resulting in increasing use of life cycle assessment (LCA). Bioenergy systems are global and complex, and market forces can result in significant changes, relevant to LCA and policy. The goal of this paper is to illustrate the complexities associated with LCA, with particular focus on bioenergy and associated policy development, so that its use can more effectively inform policymakers. Methods The review is based on the results from a series of workshops focused on bioenergy life cycle assessment. Expert submissions were compiled and categorized within the first two workshops. Over 100 issues emerged. Accounting for redundancies and close similarities in the list, this reduced to around 60 challenges, many of which are deeply interrelated. Some of these issues were then explored further at a policyfacing workshop in London, UK. The authors applied a rigorous approach to categorize the challenges identified to be at the intersection of biofuels/bioenergy LCA and policy. Results and discussion The credibility of LCA is core to its use in policy. Even LCAs that comply with ISO standards and policy and regulatory instruments leave a great deal of scope for interpretation and flexibility. Within the bioenergy sector, this has led to frustration and at times a lack of obvious direction. This paper identifies the main challenge clusters: overarching issues, application and practice and value and ethical judgments. Many of these are reflective of the transition from application of LCA to assess individual products or systems to the wider approach that is becoming more common. Uncertainty in impact assessment strongly influences planning and compliance due to challenges in assigning accountability, and communicating the inherent complexity and uncertainty within bioenergy is becoming of greater importance. Conclusions The emergence of LCA in bioenergy governance is particularly significant because other sectors are likely to transition to similar governance models. LCA is being stretched to accommodate complex and broad policy-relevant questions, seeking to incorporate externalities that have major implications for long-term sustainability. As policy increasingly relies on LCA, the strains placed on the methodology are becoming both clearer and impedimentary. The implications for energy policy, and in particular bioenergy, are large

Embedding Circular Economy Principles into Urban Regeneration and Waste Management: Framework and Metrics

In a highly urbanised world, cities have become main centers of resource consumption and generation of waste. The notion of the circular economy (CE) identifies strategies for slowing and narrowing resource use through the prevention of waste, improvement of resource use, and substitution of the use of primary resources with recovered materials (and energy). The literature has recently started to explore the concept of circular cities, and a number of cities around the globe have adopted circular economy strategies. Urban regeneration can play a critical role in enabling more circular loops of resources and contribute to more sustainable urban environments; however, there is a lack of contributions in the literature that explore the circularity of urban regeneration projects. The aim of this research is to address this gap by providing a framework and metrics to embed circular economy principles into urban regeneration. The proposed framework and set of metrics are then applied to a case study in West London to quantitatively assess CE implications and point to opportunities to increase circularity. Three main scenarios are developed to assess resource impacts of different waste strategies. The maximizing recycling scenario suggests that over 65% recycling and just under 35% energy recovery could be achieved for the area. However, findings suggest potential trade-offs between strategies centered around energy recovery from waste and strategies that prioritise recycling of recyclable fractions from waste. The three scenarios are then assessed against the CE metrics proposed. Again, here, ‘maximising recycling’ better aligns with the proposed CE metrics and contributes to cutting around 50% of GHG emissions associated with management/disposal of residual waste while increasing opportunities for resource recovery. Finally, some conclusions are drawn pointing to pathways to maximise optimal resource use and infrastructural provision in urban regeneration