Introduction of the circular economy within developing regions: A comparative analysis of advantages and opportunities for waste valorization

Shifting perceptions of informal operators in the service and value chains: A retrospective of 40 years of observation and advocacy for informal recyclers and waste service providers, through the eyes of five global participant-researchers

This article offers a reflective retrospective of the literature and practice on the informal waste and recycling sector. The authors have joined to share our experience and knowledge on the interface between the formal solid waste sector and informal recyclers and operators. Together, we discuss where this discourse has come from, where it is now, and where we, as practitioners, think it is going. We share our understanding of the waste and recycling sectors and how informality within them functions. The retrospective covers nearly 40 years of research, practice, advocacy, action, writing and intervention. The main storyline is how the public and private solid waste authorities and service providers relate to informal operators in both recycling ('the (private) value chains') and waste management ('the (public) service chain'). The recurring theme is how engaged scholarship and practice have interacted with, modified and improved the position of informal operators and workers and contributed to positive outcomes in both service and value chains. Throughout the period covered by this retrospective, opinions and framing on all sides have shifted substantially through the years, whereas the economic activities of informal recyclers and informal waste collection service providers have remained largely unchanged. Although we refer to both scientific and operational documents, we do not have the ambition to produce a scientific paper. Rather, we follow other authors of the special issue in referring to ourselves as involved witnesses who share a commitment to improving waste and recycling practices at the boundary of formal and informal systems.

Anaerobic membrane bioreactors for municipal wastewater: Progress in resource and energy recovery improvement approaches

Anaerobic membrane bioreactor (AnMBR) offer promise in municipal wastewater treatment, with potential benefits including high-quality effluent, energy recovery, sludge reduction, and mitigating greenhouse gas emissions. However, AnMBR face hurdles like membrane fouling, low energy recovery, etc. In light of net-zero carbon target and circular economy strategy, this work sought to evaluate novel AnMBR configurations, focusing on performance, fouling mitigation, net-energy generation, and nutrients-enhancing integrated configurations, such as forward osmosis (FO), membrane distillation (MD), bioelectrochemical systems (BES), membrane photobioreactor (MPBR), and partial nitrification-anammox (PN/A). In addition, we highlight the essential role of AnMBR in advancing the circular economy and propose ideas for the water-energy-climate nexus. While AnMBR has made significant progress, challenges, such as fouling and cost-effectiveness persist. Overall, the use of novel configurations and energy recovery strategies can further improve the sustainability and efficiency of AnMBR systems, making them a promising technology for future sustainable municipal wastewater treatment.

Boosting hydrogen production in Rhodospirillum rubrum by syngas-driven photoheterotrophic adaptive evolution

Rhodospirillum rubrum is a photosynthetic purple non-sulphur bacterium with great potential to be used for complex waste valorisation in biotechnological applications due to its metabolic versatility. This study investigates the production of hydrogen (H2) and polyhydroxyalkanoates (PHA) by R. rubrum from syngas under photoheterotrophic conditions. An adaptive laboratory evolution strategy (ALE) has been carried out to improve the yield of the process. After 200 generations, two evolved strains were selected that showed reduced lag phase and enhanced poly-3-hydroxybutyrate (PHB) and H2 synthesis compared to the parental strain. Genomic analysis of the photo-adapted (PA) variants showed four genes with single point mutations, including the photosynthesis gene expression regulator PpsR. The proteome of the variants suggested that the adapted variants overproduced H2 due to a more efficient CO oxidation through the CO-dehydrogenase enzyme complex and confirmed that energy acquisition was enhanced through overexpression of the photosynthetic system and metal cofactors essential for pigment biosynthesis.

Factors affecting the adoption of circular economy in mining companies of developing economies - A Namibian stakeholder perspective

The factors influencing the adoption and implementation of CE in developing countries are not yet fully examined. By focusing on the Namibian mining sector, this study highlights the perspectives of local stakeholders on CE adoption in a developing country. The mine managers recognized that waste is problematic and that CE practices are beneficial for mining companies and Namibia at large. Our findings also indicated that stronger academic institutions providing CE training and helping develop CE solutions, public awareness campaigns, financial support for CE practices, cooperation among industry stakeholders, and clear CE policy would all help drive the implementation of CE.

Can tourism support resource circularity in small islands? On-field analysis and intervention proposals in Madagascar

Open dumping and burning of solid waste are common practices in low-income countries. On small and touristic islands, the problem is exacerbated due to the additional volume of waste amount generated by tourists. This article presents how, using Nosy Be island in Madagascar as a case study, waste recovery and recycling can be fostered by tourism to tackle the waste challenge. About 95% of the waste of Nosy Be is openly dumped, discarded to sea or openly burned. Field analysis, interviews with local stakeholders and waste flow analysis served as methodological tools to assess the current solid waste management (SWM) system of Nosy Be. Stakeholder mapping and involvement as well as first exchange among local and international actors provided the basis to identify key practice and opportunities. Research findings highlight the importance of active participation and involvement of local partners supported by international experts, to suggest how touristic centres can serve as core of circular approaches. The article presents potential circular models to be implemented in Nosy Be, taking tourism as the entry point including the aspects of financial support, separated waste flows and the interest in 'green tourism marketing'. This case study underlines how international cooperation, touristic activities and common efforts can potentially help low-income communities improve their SWM practices.

Financing mechanism for solid waste management in Anambra, Nigeria: analyses of emerging challenges and implication for circular economy

Waste management is a critical public service provided by municipalities around the world. It is often problematic, inefficient, and abysmally performed in developing countries. Among the problems associated with waste management in these global locations is the issue of finance. Finance is required for both capital investment and operational costs. Methods of waste management financing differ from place to place due to cultural, political, and socio-economic peculiarities. Understanding these conditionalities is necessary to be able to proffer sustainable solutions. Despite these facts, there is limited comprehensive and relevant academic literature on waste management financing mechanisms in developing countries both in the past and recent times. This work addresses a significant gap in the literature by studying the mechanism for waste management financing in developing countries using Anambra State, Nigeria, as a case study. The current study further investigated the associated challenges and opportunities and made critical discussions on the implications on the circular economy. User fees and subsidies from the government are the major financing sources. The absence of cost-revenue model analysis, economic and institutional volatility, the unwillingness of the service users to pay fees, and lack of transparency are major challenges to the financial sustainability of waste management in the studied context. The creation of incentives for behavioral changes, adoption of neo-liberal policies, and formal integration of informal waste pickers are factors that can minimize the cost of waste management services while promoting a circular economy.

A systematic review of coastal zone integrated waste management for sustainability strategies

Coastal areas stand out because of their rich biodiversity and high tourist potential due to their privileged geographical position. However, one of the main problems in these areas is the generation of waste and its management, which must consider technical and sustainable criteria. This work aims to conduct a systematic review of the scientific literature on integrated solid waste management (ISWM) by considering scientific publications on the scientific basis for the proposal of sustainability strategies in the context of use and efficiency. The overall method comprises i) Search strategy, merging and processing of the databases (Scopus and Web of Science); ii) Evolution of coastal zone waste management; iii) Systematic reviews on coastal landfills and ISWM in the context of the circular economy; and iv) Quantitative synthesis in integrated waste management. The results show 282 studies focused on coastal landfills and 59 papers on ISWM with the application of circular economy criteria. Systematic reviews allowed for the definition of criteria for the selection of favorable sites, such as i) sites far from the coastline, ii) impermeable soils at their base to avoid contamination of aquifers, iii) use of remote sensing and geographic information system tools for continuous monitoring, iv) mitigation of possible contamination of ecosystems, v) planning the possibility of restoration (reforestation) and protection of the environment. In coastal zones, it is necessary to apply the ISWM approach to avoid landfill flooding and protect the marine environment, reducing rubbish and waste on beaches and oceans. Therefore, applying the circular economy in ISWM is critical to sustainability in coastal environments, with the planet's natural processes and variations due to climate change.

Envisioning the innovative approaches to achieve circular economy in the water and wastewater sector

Given the challenges of urbanization and rapid resource depletion, policymakers have been compelled to abandon the old sequential paradigm of "take-make-use-dispose" to a circular approach that prioritizes preservation of natural resources. The circular economy represents a sustainable management concept that focuses on reducing, recovering, reusing, and recycling waste. While significant strides have been made in implementing circular economy principles in various industries such as automotive, electronics, and construction, particular attention has been given to the water and wastewater domains due to imbalances in water resources. Here we review the global progress of circular economy adoptability in the water and wastewater domains, considering technical, environmental, economic, and social perspectives. It assesses the current state of circular economy integration in the wastewater domain worldwide and presents approaches to promote and accelerate its adoption. The study critically examines the principles of waste management, known as the 6Rs (reclaim, restore, recycle, reduce, recover, reuse), in order to formulate effective strategies for integrating circular economy practices in the water and wastewater domains. Additionally, the study provides an overview of existing research conducted on different aspects of circular economy. Finally, the study analyzes the challenges and opportunities associated with implementing circular economy principles in the water sector.

Post-closure Cost Efficiency in Public Versus Private Landfills: The Case of Emilia-Romagna (Italy)

Waste management systems have developed in recent years toward the adoption of sustainable management principles and practices, such as circular economy, zero waste, resource efficiency, waste avoidance, re-use, and recycling. Nevertheless, landfills continue to be used for waste disposal despite their risks related to contamination and effects on urban development. Most research on landfills focuses on their operational and technical aspects, while the performance and cost efficiency in managing landfills is less commonly studied, especially their post-closure management. However, improving efficiency is very relevant in the context of scarce public sector resources. This paper, therefore, analyzes the efficiency of post-closure management of landfills. Drawing on agency and stewardship theories, we focus on the difference in efficiency between public and private management of post-closure landfills. We use a linear mixed regression model to analyze data from 2015 to 2018 relating to 54 landfills (79% of which are privately managed) in the Emilia-Romagna region of Italy. The results show that public management is more efficient than private management. Results contribute to defining drivers of cost and confirming a disparity in the performance of private and public management. Our results cast doubt on the assumption, which is prevalent in new public management theory, that private operators are more efficient than public ones. We conclude by highlighting that to reach efficiency, it is better to increase the effectiveness of regulation in terms of value for money, without pre-determined preferences for the type of management.

Prioritizing action plans to save resources and better achieve municipal solid waste management KPIs: An urban case study

The management of municipal solid waste (MSW) in cities is one of the most complex tasks facing local administrations. For this reason, waste management performance measurement structures are increasingly implemented at local and national levels. These performance structures usually contain strategic objectives and associated action plans, as well as key performance indicators (KPIs) for organizations investing their resources in action plans. This study presents the results of applying a methodology to find a quantitative-based prioritization of MSW action plans for the City Council of Castelló de la Plana in Spain. In doing so, cause-effect relationships between the KPIs have been identified by applying the principal component analysis technique, and from these relationships it was possible to identify those action plans which should be addressed first to manage public services more efficiently. This study can be useful as a tool for local administrations when addressing the actions included in their local waste plans as it can lead to financial savings.Implications: This paper introduces and implements a methodology that uses principal component analysis to analyze real data from waste management KPIs and provide municipal solid waste managers with a decision-making tool for prioritizing action plans. The methodology saves financial resources and time, as well as reinforcing the probability of reaching the meta values of the main performance system KPIs.

Analysis in circular economy research in Latin America: A bibliometric review

Circular Economy (CE) plays a crucial role in Latin America, where the transition to new economic development models poses significant challenges. This study conducts a bibliometric analysis of CE research in the region to identify critical areas of development, influential authors, organizations, and future research trends. This analysis aims to highlight the progress made in the CE field in Latin America and identify areas for improvement to promote sustainable development. Using the Scopus database, we analyzed 632 research papers, and the rising number of CE publications in Latin America suggests a continuous growth trajectory, expected to reach over 2500 studies by 2026. The analysis reveals that Brazil leads CE research with 274 publications, Waste Management being the most studied topic. The study highlights the region's growing trend towards implementing innovative and sustainable solutions for waste management and resource utilization, such as bioengineering and biochemistry processes, which could positively impact the region's economy and environment. The findings of this study provide valuable insights for policymakers and researchers aiming to promote sustainable development in Latin America.

A multi-criteria approach to assess interconnections among the environmental, economic, and social dimensions of circular economy

The debate about the negative impacts that production and consumption cause on the environment is in vogue. Strategies that point to a sustainable, healthy, and resilient path are being sought. One of these paths is the Circular Economy, which emerges as an alternative to reduce the socio-environmental impacts caused by the linear model of production-use-disposal, presenting opportunities to generate revenue, income, and wealth with circular processes. However, despite the circular economy being considered an essential strategy to improve overall performance toward sustainability in its three dimensions, recent research has shown that the predominant focus of circular approaches is on the economic and environmental dimensions. At the same time, the social aspects still need to be explored. This article addresses this problem, aiming to explore circular economy environmental, economic, and social elements in three economic blocs from 2000 to 2020 using the Five Sector Sustainability Model, establishing a baseline to co-create an equitable and regenerative future. The results showed that ASEAN in 2000 occupied the first position in the general ranking. The European Union had the best classification in the economic sector, and Mercosur was the best regarding social benefits. In 2020, while the European bloc was better positioned in the general ranking, the South American bloc occupied the last post in almost all sectors. Comparatively, the highest-ranked bloc in 2020 in overall sustainability is more in line with the UN SDG due to circular actions oriented towards the three fundamental pillars of sustainability.

Symbiotic integration of waste disposal capability within a city cluster: The case of the Yangtze River Delta

With the ongoing urbanization in developing regions, integrating regional waste disposal capability is challenging due to unbalanced economic development and rising environmental issues. This research proposed a multi-dimensional symbiotic integration of waste disposal capability. Applying data from the Yangtze River Delta (YRD) in China, we first explore the waste flows and interactions between cities to identify the possibility of inter-municipal collaboration based on the augmented gravity model. We then employ social network analysis to categorize the cities in the collaborative network of waste disposal into subgroups by functionalities. Finally, we proposed the top-down framework of symbiotic networks for waste disposal. Our findings indicate that YRD cities can be classified into four types according to their waste density and disposal efficiency: High-High, Low-High, Low-Low, and High-Low. We also identify three types of inter-municipal collaborative relationships: between high-density and high-efficiency cities, between high-density cities, and between high-efficiency cities. The city subgroups can be categorized into "high-efficiency clusters," "high-density clusters," and "hub clusters," which pave the way for a shared or complementary urban symbiosis in the waste recycling industry. The division of roles among subgroups enables symbiotic activities within the city cluster. This paper extends the spatial scope of industrial symbiosis literature and has practical implications for transitioning to a circular economy in waste management of developing countries.

Circular economy approach for sustainable solid waste management: A developing economy perspective

The notion of circular economy (CE) strengthens the approach to sustainable development (SD). It is perceived that the adoption of CE can unlock half a trillion dollars of economic value in India by the year 2030. However, embracing the CE concept can be considered a panacea to the existing issues associated with solid waste management (SWM). The proposed study explores current waste management practices and assesses the inadequacy to infer the CE as a solution for successful waste management practices. The work provides an overview of SWM in India and emphasizes the inclusion of CE in the Indian SWM sector. The comprehensive review depicts existing, and emerging waste management approaches to form a CE by processing the waste efficiently and fuelling an SD movement. The cradle-to-cradle approach in CE, national solid waste compliances/legislation, key initiatives taken by the Governments, and the influence of industry and legal framework on CE were also discussed. The work will facilitate policy and decision-makers to include CE in the Indian SWM sector.

Poultry farmers' knowledge, attitude, and practices toward poultry waste management in Bangladesh

Background and Aim

The improper handling of poultry litter and waste poses risks to humans and environment by introducing certain compounds, elements, and pathogenic microorganisms into the surrounding environment and food chain. However, understanding the farmers' knowledge, attitude, and practices (KAP) could provide insights into the constraints that hinder the appropriate adoption of waste management. Therefore, this study aimed to assess poultry farmers' KAP regarding waste management issues.

Materials and Methods

A cross-sectional KAP study was conducted with native poultry keepers and small-scale commercial poultry farmers in seven districts of Bangladesh. In the survey, 385 poultry producers were interviewed using validated structured questionnaires through face-to-face interviews to collect the quantitative data in their domiciles.

Results

The overall KAP of farmers regarding poultry waste management issues demonstrated a low level of KAP (p = 0.001). The analysis shows that roughly 5% of farmers have a high level of knowledge of poultry waste management issues, followed by around one-third of respondents having a moderate level of knowledge. Considering the attitude domain, more than one-fifth of native poultry keepers and nearly two-thirds of commercial producers demonstrated a low level of attitude toward poultry waste management. Considering the overall analysis, roughly half of the respondents found a high level of attitude, and over half of the farmers showed a moderate level of attitude toward poultry waste management issues. The analysis showed that the level of good practices for native and commercial poultry production systems is estimated at 77.3% versus 45.9%, respectively, despite the farmers' lesser knowledge and attitudes toward poultry waste management systems. Overall, analysis showed that nearly 60% and 40% of poultry producers had high and moderate levels, respectively, of good practices in poultry waste management issues.

Conclusion

Analysis of the KAP data shows that farmers had a low level of KAP toward poultry waste management. The result of this study will assist in formulating appropriate strategies and to adopt poultry waste management solutions by poultry farmers to reduce environmental degradation.

Plastic waste reprocessing for circular economy: A systematic scoping review of risks to occupational and public health from legacy substances and extrusion

The global plastics reprocessing sector is likely expand as the circular economy becomes more established and efforts to curb plastic pollution increase. Via a critical systematic scoping review (PRISMA-ScR), we focused on two critical challenges for occupational and public health that will require consideration along with this expansion: (1) Legacy contamination in secondary plastics, addressing the risk of materials and substances being inherited from the previous use and carried (circulated or transferred) through into new products when reprocessed material enters its subsequent use phase (recycled, secondary plastic); and, (2) Extrusion of secondary plastics during the final stage of conventional mechanical reprocessing. Based on selected literature, we semi-quantitatively assessed nine risk scenarios and ranked them according to the comparative magnitude of risk to human health. Our analysis highlights that despite stringent regulation, industrial diligence and enforcement, occasionally small amounts of potentially hazardous substances contained in waste plastics are able to pass through established safeguards and re-enter (cascade into) the next use phase (product cycle) after being recycled. Although many of these 'inherited' chemical substances are present at concentrations unlikely to pose a serious and imminent threat, their existence may indicate a wider or possible increase in pollution dispersion. Our assessment indicates that the highest risk results from exposure to these substances during extrusion by mechanical reprocessors in contexts where only passive ventilation, dilution and dispersion are used as control measures. Our work sets the basis to inform improved future risk management protocols for a non-polluting circular economy for plastics.

Direct Membrane Filtration of Municipal Wastewater: Studying the Most Suitable Conditions for Minimizing Fouling Rate in Commercial Porous Membranes at Demonstration Scale

This study aimed to evaluate the feasibility of applying a commercial porous membrane to direct filtration of municipal wastewater. The effects of membrane pore size (MF and UF), treated influent (raw wastewater and the primary settler effluent of a municipal wastewater treatment plant) and operating solids concentration (about 1 and 2.6 g L^-1) were evaluated on a demonstration plant. Filtration periods of 2-8 h were achieved when using the MF membrane, while these increased to 34-69 days with the UF membrane. This wide difference was due to severe fouling when operating the MF membrane, which was dramatically reduced by the UF membrane. Use of raw wastewater and higher solids concentration showed a significant benefit in the filtration performance when using the UF module. The physical fouling control strategies tested (air sparging and backwashing) proved to be ineffective in controlling UF membrane fouling, although these strategies had a significant impact on MF membrane fouling, extending the operating period from some hours to 5-6 days. The fouling evaluation showed that a cake layer seemed to be the predominant reversible fouling mechanism during each independent filtration cycle. However, as continuous filtration advanced, a large accumulation of irreversible fouling appeared, which could have been related to intermediate/complete pore blocking in the case of the MF membrane, while it could have been produced by standard pore blocking in the case of the UF membrane. Organic matter represented more than 70% of this irreversible fouling in all the experimental conditions evaluated.

A Systematic Review on Biosurfactants Contribution to the Transition to a Circular Economy

Since they are more environmentally acceptable than their chemically synthesized counterparts, biosurfactants are used in a wide range of environmental applications. However, less research has been done on biosurfactants within the context of the circular economy, despite their theoretical potential to fulfill a number of circular economy ambitions, including closing the consumption loop, regenerating natural systems, and maintaining resource value within the system. Hence, the main objective of this review is to identify and analyze the contributions of biosurfactants to the implementation of the circular economy. A final sample of 30 papers from the Web of Science database was examined. We identified five broad categories of contributions: waste stream-derived production, combating food waste, strengthening soil health, and improving the efficiency of water resources. We concluded that, while manufacturing biosurfactants from waste streams can reduce production costs, optimizing yield remains a contentious issue that complicates the adoption of biosurfactants into the circular economy framework.

Barriers to circular supply chain: the case of unorganized tire retreading in India

Purpose

To understand the role of the unorganized sector in the push toward a circular economy (CE), the authors consider the case of the unorganized tire retreading industry in India and examine the barriers it faces in contributing to a circular tire supply chain in India.

Design/methodology/approach

The authors used grounded theory methodology (GTM) to understand the barriers to realizing the CE in the Indian unorganized tire retreading industry. This methodology facilitates the acquisition of new insights into an existing phenomenon or in studying emerging areas that require investigation.

Findings

Through the analysis, the authors tease out ten critical barriers that impede the Indian unorganized tire retreading industry. The two most vital barriers are the lack of effective promotional methods and the poor implementation of standards.

Research limitations/implications

This study emphasizes the importance of further investigating the potential role of the unorganized sector in fostering the transition to a CE in emerging economies.

Practical implications

The research provides useful policy prescriptions to regulators and insights to original tire manufacturers (OTMs) that enable the unorganized tire retreaders in India to contribute to the movement toward a circular supply chain (CSC).

Originality/value

This study is the first to systematically examine the unorganized sector to understand the barriers to CE. This study provides an original theoretical contribution by expanding the scope of stakeholder and institutional theories.

Waste management and green technology: future trends in circular economy leading towards environmental sustainability

The effective treatment of waste to be used as a resource in future has a major role in achieving environmental sustainability and moving towards circular economy. The current research is aimed to provide in-depth detail regarding prominent trends and research themes, evolution, future research orientation, main characteristics, and mapping of research publications on waste management, technological innovation in circular economy domain from the year 2000 to 2021. Different analyses including text mining and bibliometric and content analyses were applied to answer the research question and provide the details on aforementioned variables. From the bibliometric analyses, a total of 1118 articles were drawn out from the Scopus database to conceptualize the core body of research. As a result, the following themes were identified: electronic waste, circular economy transition, plastic waste, bio-based waste management, lifecycle assessment, and ecological impacts, and construction and demolition waste management. The highlighted features, future research orientation, and prominent research perspective can provide guideline for future research to enrich the literature through conducting studies on provided research directions and help lead waste management and technological innovation policymakers, professionals, and practitioners in moving towards circular transition.

Evaluating the Feasibility of Employing Dynamic Membranes for the Direct Filtration of Municipal Wastewater

The aim of this study was to assess the feasibility of using dynamic membranes for direct filtration of municipal wastewater. The influence of different alternative supporting materials (one or two layers of flat open monofilament woven polyamide meshes with 1 or 5 µm of pore size) was studied. A stable short-term self-forming DM was achieved (from some hours to 3 days) regardless of the supporting material used, producing relatively similar permeate qualities (total suspended solids, chemical oxygen demand, total nitrogen, total phosphorous and turbidity of 67-88 mg L^-1, 155-186 mg L^-1, 48.7-50.4 mg L^-1, 4.7-4.9 mg L^-1, and 167-174 NTU, respectively). A DM permeability loss rate of from 5.21 to 10.03 LMH bar^-1 day^-1 was obtained, which depended on the supporting material used. Unfortunately, the preliminary energy, carbon footprint, and economic evaluations performed showed that although DMs obtain higher pollutant captures than conventional treatments (primary settler), the benefits are not enough to justify their use for treating average municipal wastewater. However, this alternative scheme could be suitable for treating higher-loaded MWW with a higher fraction of organic matter in the non-settleable solids.

Sustainable approach for valorization of solid wastes as a secondary resource through urban mining

The incessant population has increased the production and consumption of plastics, paper, metals, and organic materials, which are discarded as solid waste after their end of life. The accumulation of these wastes has created growing concerns all over the world. However, conventional methods of solid waste management i.e., direct combustion and landfilling have caused several negative impacts on the environment (releasing toxic chemicals and greenhouse gases, huge land use) besides affecting human health. Therefore, it is requisite to determine sustainable alternative technologies that not only help in mitigating environmental issues but also increase the economic value of the discarded solid wastes. This process is known as urban mining where waste is converted into secondary resources and thereby conserves the natural primary resources. Thus, this review highlights the technological advancements in the valorization process of discarded wastes and their sustainable utilization. We also discussed several limitations of the existing urban mining processes and further the feasibility of valorization techniques was critically analyzed from a techno-economical perspective. This paper recommends a novel sustainable model based on the circular economy concept, where waste is urban mined and recovered as a secondary resource to support the united nations sustainable development goals (SDGs). The implementation of this model will ultimately help the developing countries to achieve the target of SDGs 11, 12, and 14.

A neoteric approach for the complete valorization of Typha angustifolia leaf biomass: A drive towards environmental sustainability

Exploring new biomass resources and developing a sustainable process for holistic utilization has become crucial due to the high demand for bio-based chemicals as alternatives to petrochemicals. Herein, we describe a novel approach to valorize the Typha angustifolia leaves, underutilized biomass into cellulose, hemicellulose and lignin nanoparticles. The process was framed in a sequence to isolate hemicellulose in the first step due to its highly reactive nature and then separate cellulose and lignin. Among the various natural deep eutectic solvents used in screening experiments, LA/ChCl (2:1) was chosen for hemicellulose solubilization and a dissolution yield of 95.97 ± 1.8% was obtained in 30 min at 240 W microwave power. Then the residual solid was delignified using NaOCl₂ at 180 W microwave power and a yield of 97 ± 0.75% was obtained in 15 min. Dissolved hemicellulose and lignin were precipitated using anti-solvents. The proposed approach achieved a recovery yield of 95.5 ± 1.2% cellulose, 91.9 ± 2.6% hemicellulose and 89.5 ± 1.6% lignin. Subsequently, the isolated particles were converted into nanoparticles by intense ultrasonication. Spherical shaped nanocellulose, nanohemicellulose and nanolignin were obtained with an average size of 76 ± 7 nm, 86 ± 9 nm, and 64 ± 5 nm, respectively. The produced nanocellulose had a crystallinity of 77.36% with the thermal stability of 265 °C. Nanohemicellulose and nanolignin were found to be semicrystalline with thermal stability up to 245 °C and 275 °C, respectively. The characterization results of the nanoparticles isolated from Typha angustifolia leaves are indicative of their wide range of biomedical and material science applications. This research could open a window for complete utilization of biomass in biorefinery and sustainable management of an invasive plant Typha angustifolia.

Rudimentary Assessment of Waste-to-Wealth of Used Tires Crumbs in Thermal Energy Storage

Disposing of waste tires is a major environmental and economic issue. Different recycling methods have been studied to account for its re-usage. This project aims to evaluate the possible usage of shredded waste tires in thermal energy storage (TES) applications, whether they are sensible or latent materials. An experimental setup has been developed with seven compartments. Each compartment contains different TES materials, including tire crumbs, paraffin wax, paraffin wax with shredded tires, pebbles, pebbles with shredded tires, concrete, and concrete with shredded tires. In all cases of the mixture, the base materials are 60%vol, and the tire crumbs are 40%vol. The experimental included three locations for temperature measurements in each compartment, solar irradiation, and ambient temperature. The tests were carried out from 9:00 a.m. till 7:00 p.m. and repeated for five days to account for the weather’s daily change. Results revealed that mixed 60%vol pebbles and 40%vol shredded tires have the highest recorded temperature, at 112.5 °C, with a 39.5% increment compared to pure pebbles. The interesting finding is that the added tire crumbs reduced the storage capacity of the paraffin wax, which is latent TES material. At the same time, it increased the storage capacity of the concrete and pebbles, which are sensible TES materials. Adding 40%vol of tire crumbs to the paraffin wax has a negative effect, where the thermal storage capacity is reduced by 43%, and the discharge capacity is reduced by 57%. In contrast, the concrete and the pebbles show enhanced storage capacity. Adding 40%vol of crumbs to the concrete increased the charging capacity by 54% and discharging capacity by 33.7%. The 40%vol added tire crumbs to the pebbles increased its charging capacity by 25% and the discharging capacity by 33%. The rudimentary assessment encourages further investigations on using the wasted tires crumbs for TES. The results reveal the probability of a circular economy using wasted tires with sensible TES for solar-to-thermal energy conversion.

Barriers and Enablers of Circular Economy Implementation for Electric-Vehicle Batteries: From Systematic Literature Review to Conceptual Framework

With the burgeoning transition toward electrified automobile fleets, electric-vehicle batteries (EVBs) have become one of the critical aspects to be considered to avoid resources issues while achieving necessary climate goals. This paper compiles and syntheses reported barriers, enablers, involved stakeholders, and business models of Circular Economy (CE) implementation of the EVBs based on a systematic literature review (SLR). Findings indicate that inefficient and inadequate government policy, lack of safety standards, and high recycling costs are the three most reported barriers. The barriers have interconnections with each other, implying the necessity for simultaneous strategies. Based on the barriers-enablers analysis, the key strategies establishing the CE for the EVBs are innovative business models, economic incentives, EVB standards, legal environmental responsibilities, and certification, whereas the optimized supply-chain operations can be realized through eco-design of the EVBs, battery modularization, proper technology for checking, diagnosing, tracking, information sharing, extensive collaboration, alignment of supply-chain stakeholders, innovative business model, and certification. A conceptual framework presenting the required strategies for both establishing the CE and optimizing the circular supply chain system of the EVBs was then proposed. Potential future research directions are also discussed.

Circular Economy Indicators for the Assessment of Waste and By-Products from the Palm Oil Sector

A circular economy (CE) promotes the reuse, reincorporation and valuation of waste and by-products under the framework of sustainable development through models and indicators that evaluate scenarios of second use and reduction in non-incorporated outputs to reduce negative externalities and pressures on the dimensions of development. A CE model applied to the transformation process of RFF in agro-industries is developed, which consists in the identification of the residue coefficients of EFB (22.48% ± 0.8), fiber (15.58% ± 0.49), husk (6.03% ± 0.66) and ash (0.55% ± 1.67). Subsequently, the valuation trends of potential second use were verified through a systematic review, which allowed the construction of the scenario of avoided costs of USD 678,721.5, a product of the total use of the outputs under bioenergy and nutrient source approaches. Finally, the RRSFM indicator was constructed, which can reach the level of 72% and a degree of improvement of 26% by 2026. In parallel, the HCRRS indicator revealed a reduction of 57.1%, 59.6% and 82.8% in emissions of t CO2-eq product in the comparison of scenarios for the use of residues and by-products of palm oil from agro-industries in the Casanare Department.

Perspectives in solid recovered fuel production in Bolivia: Analysis of characteristics and potential benefits

Solid recovered fuels (SRF) can provide another treatment option to the solid waste management (SWM) sector. However, in developing countries, to date, this system approach has not found considerable application. In Bolivia, SRF is not deemed within the national regulation and the final disposal in open dumping areas is still a reality. This research article provides the first attempt in evaluating the SRF characteristics and its potentialities in Bolivia, taking La Paz as a case study. Laboratory analysis of the rejects produced after selective collection and sorting has been conducted, focusing on non-hazardous and non-recyclable waste fractions. The international standards related to EN 15359:2011 for the classification of the SRF were employed, assessing the most feasible mix of materials to provide the highest classification of SRF in terms of low calorific value (LCV), chlorine, and mercury concentration. Results reported that the SRF made of 80% plastics (85% PE and 15% PP) and 20% cellulosic (blend 2), as well as 30% plastics (50% PP and 50% PE) and 70% cellulosic (blend 1), can be considered an alternative fuel in Bolivia. On balance, it has been estimated that the use of non-recyclable plastics and cardboard from municipal solid waste can provide, on average, about 0.9-2.7 billion MJ of energy for cement kilns, solving about 1.4-5.3% of the SWM issues and covering about 8-23.4% of the energy demand for cement production in Bolivia. These results are novel for the scientific literature for estimating the potentialities of SRF in Latin America.

A bibliometric analysis of circular economy in the fields of business and economics: towards more action-oriented research

In this paper, we reveal and systemize development trends in the scientific field of the circular economy (CE). Our results imply that academic research on the CE focuses heavily on theoretical conceptualizations and technological solutions. However, these advancements alone are unlikely to help prevent from ecological collapse. With this observation in mind, we explore the potential held by a more relational, action-based approach to support a faster and more efficient transition from the linear economy to the CE. A useful combination of several bibliometric techniques gave us valuable references for re-focusing this area of science to adopt action-oriented research where a group of stakeholders collaborates and co-creates solutions. An analysis of valuable action-oriented CE studies reveals that scholars focus on the techno-economic aspect, where they develop ways to create optimal circular material and energy flows and co-design processes for products/services, as well as the organizational aspect, where they study self-sustainable community networks and participatory governance. We identify three research streams that would benefit from such action-oriented research for a faster practical implementation: sustainable supply chains, waste management, and business model innovation. A practice-based agenda is proposed to stimulate the scientific community to conduct future research on a CE that better supports companies.

A facilitating framework for a developing country to adopt smart waste management in the context of circular economy

To achieve higher standards of sustainability, the waste management sector now requires the incorporation of circular economy (CE) principles. However, an easy transition toward the particular goal would require the use of smart waste technologies. To achieve the aforementioned goal, this study aims to provide a facilitating framework for the adoption of smart waste management in the context of CE for Pakistan. To help Pakistan transition toward the new paradigm, a total of 16 critical facilitators are evaluated based on five distinctive criteria using a novel fuzzy hybrid multi-criteria decision-making (MCDM) approach. The hybrid MCDM approach includes fuzzy Stepwise Weight Assessment Ratio Analysis (SWARA) for allocating weights to the determined criteria; whereas, the fuzzy VIšekriterijumsko kompromisno rangiranje (VIKOR) approach is used to rank the critical facilitators adopted from the secondary literature. The fuzzy approach in both cases is to deal with any kind of uncertainty during the data collection process. Based on the achieved results, the study suggests that before the application of smart waste technologies in the country, Pakistan should first focus on devising regulations that effectively address the mismanagement of waste produced in the country. Also, the industries in the country need to become more responsible and should adopt environmental management systems that foster waste minimization. Lastly, the country in the third phase should focus on the wide application of digitalization both in the streams of ICT and IoT, for collecting, sharing, and receiving waste data. The study further provides policy recommendations to the respective stakeholders that will help the country achieve zero-waste CE.

Circular economy and frugal innovation: a conceptual nexus

Frugal innovation (FI) and circular economy (CE) are two concepts that are recently being deliberated among researchers, policymakers, businesses, governments, and international organizations. Being a nascent development, both still lack an extant body of theories and data. Undisputedly they both share commonalities in gathering tractions among scholars. But the conceptual relationship between them has been unclear and hence makes it difficult to understand how one can promote the other. The current work constructs a conceptual framework through literature, explicating nexus, characteristics, and indicators of the two concepts and then exploring this framework through case analysis and focus group discussion (FGD). The results of our findings show that the two concepts are outcome of considerations on resource constraints and/or resource optimization; promote redesigning of product and services to minimize resources while achieving core functionality; involve the participation of stakeholders; and are implemented in stages. Most importantly, they foster the three pillars of sustainable development-social equity, economic prosperity, and environmental quality. However, supportive policies and institutions are largely associated with the development of CE which is not the same for FI in most countries. We conclude that FI being mainly operational in the emerging economies could serve as a veritable enabling tool for promoting the CE concept in the developing regions of the globe but will require the support of formal institutions and policies.

Green growth & sustainability transition through information. Are the greener better informed? Evidence from European SMEs

The European Green Deal along with directives promoting Circular Economy support sustainability transition and foster green growth through developing appropriate funding. However, information on how to access such funding affects firms' decision to expand their business strategy. This paper investigates the effect of information about financing tools on the adoption of Circular Economy business activities by exploring whether the better-informed firms are 'greener' and what influences such decision through a switching endogenous regressor model to account for endogeneity and selectivity bias. Data on European SMEs is combined with country-specific characteristics and econometric results indicate that better informed firms are by 65 percentage points more likely to adopt an activity promoting Circular Economy, highlighting that awareness about funding tools is crucial for sustainability transition. Evidence advocates for mainstreaming information regarding funding sources to pave the way towards green growth. A rebound effect regarding the use of renewables is observed whilst evidence points towards the rejection of Porter Hypothesis. Policy makers should target in fostering a greener business environment for the firms that engage in Circular Economy practices through increased information on funding options. Findings are also pertinent to the ongoing discussion and policy agenda around acceleration of the transition to a greener European Economy.

The fate of heavy metals in the co-processing of solid waste in converter steelmaking

The improper disposal of large amounts of solid waste (SW) has led to serious ecological and environmental problems, especially heavy metal (HM) pollution. Converter steelmaking has the potential to co-process SW, but the distribution of heavy metals (HMs) during converter steelmaking is unclear. In this study, the effects of smelting temperature and slag alkalinity on the distribution of typical HMs in the SW of steel samples, steel slag, and the gas phase were investigated in a specially-made induction furnace. The results showed that upon increasing the smelting temperature, As (As2S3) was mainly distributed in the steel sample, and the HM-containing compounds Cr2O3, CrCl3, ZnCl2, ZnS, ZnO, PbCl2, PbS, and PbO were mainly distributed in the gas phase. Upon increasing the alkalinity within a certain range, the distribution of HMs in steel samples and steel slag increased gradually, while their distribution in the gas phase decreased. Thermodynamic calculations, Eh-pH diagrams, XRD patterns, and XPS spectra indicated that impurity elements in the hot metal and the CaO content affected the chemical reactions by which HM-containing compounds in the steel sample formed elemental HMs and those in steel slag existed as oxides; therefore, it is necessary to choose a suitable temperature and alkalinity for slag when disposing of different types of SW.

Emerging waste valorisation techniques to moderate the hazardous impacts, and their path towards sustainability

Due to the recent boom in urbanisation, economy, and global population, the amount of waste generated worldwide has increased tremendously. The World Bank estimates that global waste generation is expected to increase 70% by 2050. Disposal of waste is already a major concern as it poses risks to the environment, human health, and economy. To tackle this issue and maximise potential environmental, economic, and social benefits, waste valorisation - a value-adding process for waste materials - has emerged as a sustainable and efficient strategy. The major objective of waste valorisation is to transit to a circular economy and maximally alleviate hazardous impacts of waste. This review conducts bibliometric analysis to construct a co-occurrence network of research themes related to management of five major waste streams (i.e., food, agricultural, textile, plastics, and electronics). Modern valorisation technologies and their efficiencies are highlighted. Moreover, insights into improvement of waste valorisation technologies are presented in terms of sustainable environmental, social, and economic performances. This review summarises highlighting factors that impede widespread adoption of waste valorisation, such as technology lock-in, optimisation for local conditions, unfavourable regulations, and low investments, with the aim of devising solutions that explore practical, feasible, and sustainable means of waste valorisation.

Application of material flow analysis for the assessment of current municipal solid waste management in Karachi, Pakistan

This article assesses the status of the solid waste management system (SWMS) in Karachi, the largest city of Pakistan, using the material flow analysis approach, a widely applied method in waste management (WM) studies. It involves a systematic assessment of the material flows of solid waste under the current WM system. A material flow diagram is developed to visualize the input and output waste flows. This study shows the quantification and identification of municipal solid waste (MSW) flow for the year 2019, from the point of generation to the end-use and disposal. Results show that the MSW generation increased from 10,435 to 15,600 metric tonnes per day (TPD) between 2017 to 2019. Approximately, 75% of the waste generated is collected: formally (50%); and informally (25%). The material recovery is low, accounting for only 26.28% of the total waste. There is no official material recovery and recycling facility. Therefore, material recovery solely depends on the informal sector. Results show that 70% of the daily waste ends up in landfills, which is 3120 TPD more than the formally collected waste. This estimated waste of 3120 TPD flows in either due to disposal activities of the backlogged waste or informally collected waste. Overall, Karachi's SWMS performs poorly with a significant need for improvement. This study recommends adopting integrated WM approaches and inclusion of the informal sector to ensure the affordability and sustainability of the WM system.

Organic Waste Management and Circular Bioeconomy: A Literature Review Comparison between Latin America and the European Union

Worldwide, organic waste represents one of the most significant shares in the waste management system. Within the framework of circular bioeconomy, new and cutting-edge infrastructure has been developed at the European level to turn organic waste into valuable resources. The present paper aims to provide an exhaustive comparison between the European Union and Latin America regarding organic waste valorization. To this end, an introductive analysis about the state of the art circular bioeconomy in Latin America and Caribbean countries was developed. Subsequently, a systematic literature review in the context of South and Central America was conducted to detect differences and similarities in technologies and best practices for treating biowaste. The results show that the Latin American region is home to numerous bio-based infrastructures: biogas recovery, composting facilities and bioremediation strategies. Nevertheless, a conclusive remark underlines that some social, economic and political barriers are still encountered in the region, and therefore, new and locally-based studies are of paramount importance.

The Mediating Role of Policy-Related Factors in the Relationship between Practice of Waste Generation and Sustainable Construction Waste Minimisation: PLS-SEM

As the construction industry grows, it produces large volumes of construction waste, which has a tremendous environmental impact and generates public concern in the neighbouring towns. The construction industry generates a significant volume of waste and faces a challenge with poor construction waste minimisation in order to prevent adverse environmental and dumping impacts worldwide. In developing countries, regional waste management systems have increased problems. Environmental pollution (air, water, and soil) and human health issues are caused by waste produced in a country as a result of different cultural, social, and religious activities. Prior studies were reviewed to choose dimensions and items for the data gathering instrument. A pilot test was conducted to identify potential questionnaire adjustments, and hypotheses were tested using structural equation modelling (SEM). A total of 220 Malaysian construction professionals answered the survey, which yielded the results. Five hypotheses have direct correlations based on the findings, three of which have a significant effect. Furthermore, the findings reveal that policy-related factors mediate the relationship between improving factors and sustainable construction waste minimisation. In contrast, they did not mediate the relationship between current practices/generation and sustainable construction waste management. The established framework can help improve construction waste management and help achieve global sustainable development goals. The data reveal that adopting preventive plans to reduce construction waste is one of the most important aspects of enhancing profitability. This study could aid construction industry players in evaluating waste management components during the construction and design stages of a building project.

Sustainability Performance Management Framework for Circular Economy Implementation in State-Owned Plantation Enterprises

The circular economy concept needs to be part of the performance management system so that it is in line with a company’s vision and mission. Thus, the circular economy will play an important role at the operational level of companies. The circular economy needs to be internalized, starting by formulating the company’s vision and mission, establishing strategic objectives and performance indicators, and creating resource allocation policies. This research aims to design a sustainable performance management system in the context of a circular economy for state-owned plantation enterprises (SOPEs). This study used a qualitative research coding method that was validated in three SOPEs in Indonesia. Validation was performed by comparing the framework based on the conceptual formulation with the data and information obtained during field assessment. Primary data came from interviews with 15 managers, while secondary data came from official company documents. The research results show that the initial framework that was built is in accordance with the results of the exploration of the circular economy strategic objectives in the three SOPEs. The results of the 100 percent validation and perception test of managers on the range of values are important. Therefore, the proposed framework can be used in SOPE.

Approaches and Policies to Promote Zero-Waste City Construction: China’s Practices and Lessons

The rapidly growing output of solid waste has brought tremendous pressure to urban development. China launched an action plan known as “Zero-waste city” (ZWC), that refers to an urban development model aimed at reducing the generation of and enhancing the recycling of solid waste, in order to alleviate environmental impacts. Eleven cities and five special zones achieved positive results of solid waste management were selected as pilot areas for exploring empirical methods until 2019. The practices and lessons of the pilot cities need to be deeply analyzed and summarized, so as to promote successful models, learn lessons and better implement the policy comprehensively for other cities. This study presents a review of China’s ZWC policies and practices with constructive suggestions for further development. Based on the policy objective of ZWC and the field investigation of solid waste flow, five crucial approaches to developing ZWC are proposed, namely, solid waste reduction throughout the industrial chain, collaborative treatment of classified municipal solid waste (MSW), efficient utilization of agricultural waste with multiple purposes, safety control of hazardous waste flow, and optimization of market mechanisms. The case study demonstrates that the five paths are appropriate to Xuzhou city. However, deficiencies in MSW classification, pesticide packaging waste collection systems, solid waste product application, management, and policymaking, have emerged. Regulatory prohibitions, extended producer responsibility and market vitality should be adopted to improve the collection, transportation, and utilization of solid waste. Key findings from this research are to summarize crucial paths toward fulfiling ZWC goal, and to reveal some successful practices of, and lessons from ZWC construction by case studies. This study provides a method to further implement zero solid waste management in a targeted manner. The recommendations drawn from the study, which include law, market and institutional measures, may contribute to the achievement of developing sustainable cities.

A review on the potential of polyhydroxyalkanoates production from oil-based substrates

Polyhydroxyalkanoate (PHA) is a type of polyesters produced in the form of accumulated intracellular granules by many microorganisms. It is viewed as an environmentally friendly bioproduct due to its biodegradability and biocompatibility. The production of the PHA using oil substrates such as waste oil and plant oil, has gained considerable attention due to the high product yield and lower substrate cost. Nevertheless, the PHA fermentation using oil substrate is complicated due to the heterogenous fatty acid composition, varied bio-accessibility and possible inhibitory effect on the bacterial culture. This review presents the current state-of-the-art of PHA production from oil-based substrates. This paper firstly discusses the technical details, such as the choice of bacteria strain and fermentation conditions, characteristic of the oil substrate as well as the PHA composition and application. Finally, the paper discusses the challenges and prospects for up-scaling towards a cleaner and effective bioprocess. From the literature review, depending on the cell culture and the type of PHA produced, the oil platform can have a PHA yield of 0.2-0.8 g PHA/g oil substrate, with PHA content mostly from 40 to 90% of the cell dry weight. There is an on-going search for more effective oil-utilising PHA producers and lower cost substrate for effective PHA production. The final application of the PHA polymer influences the treatment needed during downstream processing and its economic performance. PHA with different compositions exhibits varied decomposition behaviour under different conditions, requiring further insight towards its management towards a sustainable circular economy.

Purchase Intentions for Brazilian Recycled PET Products—Circular Economy Opportunities

Circular economy involves structural changes in traditional business models and consumers’ behavior toward recycled products. The recycling of PET products is increasing but there is still a gap between consumption and demand for PET packaging in Brazil. In this research, waste reduction was examined under a projective scenario to the current ecological purposes in Brazil for reducing environmental pollution. In that manner, this paper aimed to comprehend the intention to purchase recycled PET products of Brazilian consumers. With a non-probabilistic and convenience sample, the study counts 422 participants. The method employed was based on structural equation modelling and partial least Squares, used to test the hypotheses of causality among the variables. Results showed the perception of low quality about recycled products reduced consumers’ intention to purchase. Additionally, the sustainability of recycled products positively influenced the intention to purchase. In addition, recycled products presented a negative impact on the perceived safety, which could influence the purchase of recycled products in Brazil. We conclude that the image that Brazilian consumers have about recycled products positively affects the intention to purchase.

Barriers and Drivers for Circular Economy 2.0 on the Firm Level: Russian Case

Historically, the development of the circular economy (CE) proceeds from the CE 1.0 stage, characterized by attention to waste management and recycling, to the CE 2.0 stage with an emphasis on resource efficiency and eco-efficiency, to the current CE 3.0 stage, in which the key factor to a company’s success is the business model. However, not all countries of the world simultaneously began transforming the national economy from a linear model to a circular one; many are still at the CE 1.0 and CE 2.0 stages, and do not have a developed system of institutions supporting the circular economy. In Russia, the concept of a circular economy has not yet received recognition in society and government; the stage of its development can be defined as CE 2.0. This study compares the barriers and drivers of CE development in the EU countries, a group of countries with a well-developed institutional support system, and in Russia, a country that does not have such a system. The study reveals that the most significant difference between countries with mature systems of institutional support and Russia lies in the regulatory sphere and in information and awareness about new available technologies and ways to increase resource efficiency, commercial attractiveness, and organizational feasibility. Changes in the first sphere are impossible without the participation of the national authorities; however, changes in the information sphere are feasible even without the government’s support. The actors in such changes can be international companies with access to resource-efficient new technologies and processes for organizing business.

Co-production in solid waste management: analyses of emerging cases and implications for circular economy in Nigeria

Co-production is a paradigm shift from the traditional model of public policymaking and service delivery that advocates for the involvement and participation of end-users of services as co-partaker in the process. In this paper, we examined the emerging models of co-production in solid waste management in Nigeria using a case study methodology. Four cases were purposefully selected for detailed exploration. The results of the analysis show that the involvement of the plurality of the non-state actors in waste management co-production brought in innovation through ICT, financial resources through grants, and increased public awareness. And have also given the service receivers a change of orientation that makes them perceive waste as a source of income rather than all rubbish needed to be discarded. However, possible exploitation of informal waste pickers, unclear business models, and absence of prior arrangement for coming together of both state and non-state actors in designing the service production are challenges to the emerging co-production cases. The current study further shows that the emerging co-production efforts have huge potential in promoting circular economy as it creates a better avenue for the implementation of extended producer responsibility (EPR), the establishment of eco-industrial parks, and safe integration of informal waste recyclers.

Temporal assessment of municipal solid waste management in Nigeria: prospects for circular economy adoption

This work reviewed the past and current status of municipal solid waste (MSW) management in Nigeria towards offering a direction for the future. The past status shows that poor policy regimes, inadequate financing mechanisms, absence of waste data, and abysmal institutional arrangement negatively impacted the MSW management outcomes in the country. At present, few improvements recorded like an increase in the number of landfills, and public-private partnerships have been largely undermined by the continuous upsurge in the urban population and lack of corresponding growth in critical capacities in terms of economic resources, technological advancement, and state-of-the-art urban infrastructures. The current waste generated in cities in Nigeria is calculated as 66,828 tonnes per day (TPD) at the total urban population of 106 million, while the projected value for 2040 will be 125,473 TPD at the urban population of 199 million. The current work further discusses prospects and implications for circular economy adoption in solid waste valorization in Nigeria.

The Role of Higher Education Institutions in the Implementation of Circular Economy in Latin America

Circular economy (CE) describes a sustainable alternative approach to the current linear economy system. It is a growing topic among scholars, practitioners, and decisionmakers; it encompasses several concepts related to sustainability and requires the synergy of multiple actors for success, including higher education institutions (HEIs) as one of the most relevant ones. Current CE is based mostly on experiences in Global North developed countries, where the concept has gained great attention and has already influenced policies and strategies. However, CE in Latin American countries (LA countries) have not yet received such attention. Thus, some “unique problems” may remain unattended, and efforts to attain a CE are more likely to fail. Likewise, the study shows how the role of HEIs in CE in LA countries has not yet been fully explored, as the literature on this topic is scarce. This paper aims to address the main research question: what is the role of HEIs in the transition to a CE in Latin American countries? For this, a two-fold methodology was performed: (i) a systematic review which allows understanding of the trends of CE research in LA and the extent of the HEIs involvement; and (ii) a narrative review, which provides insights into the state of the art of CE research (gaps, drivers, and barriers) in LA countries and how this relates to HEIs. This approach drew implications for the role of HEIs in the implementation of CE in LA countries. HEIs are key actors in this transition, contributing in several ways to the CE by collaborating with industry, assisting policy makers, building human and intellectual capital, supporting community engagement projects, influencing campus culture, linking with international CE networks, and promoting an inclusive CE discourse. This research contributes to the CE body of knowledge from a Latin-American Global South perspective by discussing the factors that aim to define the role of HEIs in the CE transition in LA countries.

Dynamics of economy-wide resource flow and consumption in China, South Korea, and Vietnam-a pan-regional analysis

The transformation of natural resources across the economy in China, South Korea, and Vietnam has been studied to give a comparative regional perspective based on trends in resource efficiency, bilateral trade dynamics, and progress on regional economic and environmental policy. Consumption of raw materials has been decomposed into economic dynamics and dematerialization, if any, has been tested based on material flow accounting approaches. As per the results, domestic material consumption (DMC) continues to increase in China and Vietnam but has stabilized in South Korea. China and South Korea have become main net importers of raw materials while Vietnam is about to enter this phase. With relatively lower material efficiency in China and Vietnam compared to South Korea, a higher reliance on intensive production and export of raw materials has been identified. As DMC has soared in all three countries, economic affluence is seen as the main driver with marginal contribution from population growth. However, technological improvements have helped reduce material usage with South Korea and China making significant progress. As South Korea has begun to dematerialize, China and Vietnam face the strong challenge of dematerializing economic growth-a reversal that could take several years if resource productivity is not significantly improved. Factors that inhibit better resource efficiency in China and Vietnam include the production and trade of low-end items, energy, and raw materials. However, the increasing economic affluence in China and Vietnam has brought significant environmental improvements from both institutional and technological perspectives-through multiple policy actions. Moreover, as more countries import net resources, regional and global supply chain competition is expected to intensify-making resource efficiency a fundamental economic objective. The results of this study provide important lessons for emerging economies to accelerate resource productivity and reduce the physical intensity of materials for sustainable economic development.

Green-based active packaging: Opportunities beyond COVID-19, food applications, and perspectives in circular economy-A brief review

The development of biodegradable packaging, based on agro-industrial plant products and by-products, can transform waste into products with high added value and reduce the use of conventional nonrenewable packaging. Green-based active packaging has a variety of compounds such as antimicrobials, antioxidants, aromatics, among others. These compounds interact with packaged products to improve food quality and safety and favor the migration of bioactive compounds from the polymeric matrix to food. The interest in the potential hygienic-sanitary benefit of these packages has been intensified during the COVID-19 pandemic, which made the population more aware of the relevant role of packaging for protection and conservation of food. It is estimated that the pandemic scenario expanded food packaging market due to shift in eating habits and an increase in online purchases. The triad health, sustainability, and circular economy is a trend in the development of packaging. It is necessary to minimize the consumption of natural resources, reduce the use of energy, avoid the generation of waste, and emphasize the creation of social and environmental values. These ideas underpin the transition from the emphasis on the more subjective discourse to the emphasis on the more practical method of thinking about the logic of production and use of sustainable packaging. Presently, we briefly review some trends and economic issues related to biodegradable materials for food packaging; the development and application of bio-based active films; some opportunities beyond COVID-19 for food packaging segment; and perspectives in circular economy.

Measuring Circular Supply Chain Risk: A Bayesian Network Methodology

The world is facing economic, as well as social, crisis due to the COVID-19 pandemic. Implementing sustainable practices is one of the possible ways to address these issues. Adopting circular oriented techniques throughout the supply chain not only guarantees economic profitability, but also provides an edge to the organization in the market of fierce global competition. The concept of implementing circularity in the supply chain is novel and dynamic in nature, and it involves certain risk. In this study, a Bayesian Network methodology is adopted to analyze how the risk propagation takes place in a circular supply chain network of an automobile organization. The circular supply chain network consists of a group of manufacturers, retailers and recyclers, located in the Delhi–NCR region. Economic, environmental, social, technological, waste management, agile vulnerability, and risk of cannibalization are the major risk categories that were identified through an extensive literature review. Further, the impact of risk on the performance of the circular supply chain is analyzed by considering performance parameters such as lost sales, impact on supply chain revenue, and inventory holding cost. Risk exposure index is incorporated into the study to analyze the vulnerability of each node. The findings of the study reveal that the reverse side of the circular supply chain can be a source of risk propagation during the implementation of the circularity concept. This work is carried out under a single industry domain. In the future, risk propagation analysis can be examined in the supply chain of other sectors. The findings of the study can assist the supply chain managers and the risk experts to focus on the areas that are more vulnerable to risk.

Clustering of EU Countries by the Level of Circular Economy: An Object-Oriented Approach

In order to effectively regulate the circular economy (CE) at the national and international levels, it is essential to have a unified and informative system of indicators for monitoring the progress in the CE. The lack of standard indicators for measuring the progress of cyclicality leads to contradictions and misunderstandings, which is a problem for the implementation of CE strategies. This paper aims to adapt dynamic clustering approaches to solving strategic management problems of circular production and consumption processes. To achieve this goal, the authors performed the following tasks: (1) tested clustering algorithms by ranking EU countries by the level of development of the circular economy; (2) identified the approach that allows the best classification of EU countries, considering changes in the indicators of the level of CE development in 2000–2019 (dynamic classification); (3) developed a software module using python libraries to classify and visualize the results. The results illustrate that the k-means algorithm has a good discriminatory ability in division of all countries of the training sample (EU countries) into several clusters with different dynamics in the development of the CE. The best quality of classification is obtained by the indicator “Generation of municipal waste per capita”; satisfactory quality of the classification is obtained by the indicator “Generation of waste excluding major mineral wastes per GDP unit”. The study results demonstrate the fundamental applicability of the object-oriented and classical statistical approach to solving strategic management problems of the CE and their potential effectiveness in terms of the clarity and information content of reflecting cyclical processes.