Circular economy life cycle cost for kerbside waste material looping process.

Rapid expansion in urban areas has engendered a superfluity of municipal solid waste (MSW) stemming from contemporary civilization, encompassing commercial sectors and human undertakings. Kerbside waste, a type of MSW, has the potential for recycling and reuse at the end of its first life cycle, but is often limited to a linear cycle. This study aimed to assess the life cycle costs of different separation and recycling methods for handling kerbside waste. A new life cycle cost model, drawing from the circular economy's value retention process (VRP) model, has been created and applied to assess the continuous recycling of kerbside glass. The study investigates two key separation techniques, kerbside recycling mixed bin recycling (KRMB) kerbside glass recycling separate bin (KGRSB) and analyses their impact on the life cycle cost of the recycling process. Additionally, the research explores two approaches of recycling and downcycling: closed-loop recycling, which pertains to the recycling of glass containers, and open-looped recycling, which involves the use of recycled glass in asphalt. The results showed when use annually collected waste as the functional unit, the KRMB model incurred lower costs compared to the KGRSB model due to its lower production output. However, when evaluated over a 1-ton production of glass container and asphalt, the KGRSB method demonstrated superior cost performance with a 40-50% reduction compared to the KRMB method. The open-loop recycling method (asphalt) incurred a higher cost compared to the closed-loop recycling method due to its larger production volume over a 21-year period.

Purchase intention for second-hand luxury goods: An empirical study of Chinese consumers.

Second-hand luxury goods feature both characteristics of luxury products like perceived value including social, emotional, and quality value, and second-hand goods like price-performance ratio. Enlarging the second-hand luxury market is of significance to protect the environment and save rare and valuable natural resources, and thus investigating the determinants of purchase intention is meaningful. From the perspective of the psychology of consumers, the influence of factors related to consumers (recycling awareness, subjective norms, attitudes, perceived behavioral control) and products (perceived value, price-performance ratio) on the intention to buy second-hand luxury goods is explored in this study through an online survey with Chinese consumers as a sample. The results are analyzed using the structural equation model (SEM) and show that consumers' attitudes, perceived behavioral control, and recycling awareness will promote the intention of purchasing second-hand luxury goods, and the perceived value and price-performance ratio of second-hand luxury goods also have a positive impact on the purchase intention. However, there is no significant relationship between subjective norms and purchase intention. In addition, this study also explores the interrelationship between constructs and draws corresponding conclusions, providing references for the subsequent development of the second-hand luxury market.

Economic benefit analysis of lithium battery recycling based on machine learning algorithm.

Lithium batteries, as an important energy storage device, are widely used in the fields of renewable vehicles and renewable energy. The related lithium battery recycling industry has also ushered in a golden period of development. However, the high cost of lithium battery recycling makes it difficult to accurately evaluate its recycling value, which seriously restricts the development of the industry. To address the above issues, machine learning will be applied in the field of economic benefit analysis for lithium battery recycling, and backpropagation neural networks will be combined with stepwise regression. On the basis of considering social and commercial values, a lithium battery recycling and utilization economic benefit analysis model based on stepwise regression backpropagation neural network was designed. The experimental results show that the mean square error of the model converges between 10-6 and 10-7, and the convergence speed is improved by 33%. In addition, in practical experiments, the model predicted the actual economic benefits of recycling a batch of lithium batteries. The results show that the predictions are basically in line with the true values. Therefore, the economic benefit analysis and prediction model for lithium battery recycling proposed in the study has the advantages of high accuracy and fast operation speed, providing new ideas and tools for promoting innovation in the field of economic benefit analysis. It has certain application potential in the evaluation of the benefits of lithium battery recycling.

Life cycle assessment and cost analysis of an innovative automatic system for sorting municipal solid waste: A case study at Milan Malpensa airport.

With the recent advancement in artificial intelligence, there are new opportunities to adopt smart technologies for the sorting of materials at the beginning of the recycling value chain. An automatic bin capable of sorting the waste among paper, plastic, glass & aluminium, and residual waste was installed in public areas of Milan Malpensa airport, a context where the separate collection is challenging. First, the airport waste composition was assessed, together with the efficiency of the manual sorting performed by passengers among the conventional bins: paper, plastic, glass & aluminium, and residual waste. Then, the environmental (via the life cycle assessment - LCA) and the economic performances of the current system were compared to those of a system in which the sorting is performed by the automatic bin. Three scenarios were evaluated: i) all waste from public areas, despite being separately collected, is sent to incineration with energy recovery, due to the inadequate separation quality (S0); ii) recyclable fractions are sent to recycling according to the actual level of impurities in the bags (S0R); iii) fractions are sorted by the automatic bin and sent to recycling (S1). According to the results, the current separate collection shows a 62 % classification accuracy. Focusing on LCA, S0 causes an additional burden of 12.4 mPt (milli points) per tonne of waste. By contrast, S0R shows a benefit (-26.4 mPt/t) and S1 allows for a further 33 % increase of benefits. Moreover, the cost analysis indicates potential savings of 24.3 €/t in S1, when compared to S0.

Influence of Canadian provincial stewardship model attributes on the cost effectiveness of e-waste management.

This paper presents a comprehensive analysis of e-waste collection and management trends across six Canadian provinces, focusing on e-waste collection rates, provincial stewardship model attributes, program strategies and budget allocations from 2013 to 2020. Temporal and regression analyses were conducted using data from Electronic Product Recycling Association reports. A group characterization based on geographical proximity is proposed, aiming to explore the potential outcomes of fostering collaboration among neighboring provinces. The analysis emphasizes the significant impact of stewardship model attributes on e-waste collection rates, with Quebec emerging as a standout case, showcasing a remarkable 61.5% surge in collection rates. Findings from group analysis reveal a positive correlation between per capita e-waste collection rate and the growth of businesses and collection sites in Western Canada (Group A - British Columbia, Saskatchewan, and Manitoba). This highlights the potential benefits of a coordinated waste management approach, emphasizing the importance of shared resources and collaborative policies. Saskatchewan and Manitoba allocated only 6.6% and 7.0% of their respective budgets to e-waste transfer and storage. British Columbia's observed steady decrease of e-waste collection rate. In Group A, stewards handled 2.18-13.95 tonnes of e-waste during the study period. The cost per tonne of e-waste tended to be lower when more e-waste is managed per steward, suggesting the potential benefits of an integrated e-waste collection and management system.

Designing a circular carbon and plastics economy for a sustainable future.

The linear production and consumption of plastics today is unsustainable. It creates large amounts of unnecessary and mismanaged waste, pollution and carbon dioxide emissions, undermining global climate targets and the Sustainable Development Goals. This Perspective provides an integrated technological, economic and legal view on how to deliver a circular carbon and plastics economy that minimizes carbon dioxide emissions. Different pathways that maximize recirculation of carbon (dioxide) between plastics waste and feedstocks are outlined, including mechanical, chemical and biological recycling, and those involving the use of biomass and carbon dioxide. Four future scenarios are described, only one of which achieves sufficient greenhouse gas savings in line with global climate targets. Such a bold system change requires 50% reduction in future plastic demand, complete phase-out of fossil-derived plastics, 95% recycling rates of retrievable plastics and use of renewable energy. It is hard to overstate the challenge of achieving this goal. We therefore present a roadmap outlining the scale and timing of the economic and legal interventions that could possibly support this. Assessing the service lifespan and recoverability of plastic products, along with considerations of sufficiency and smart design, can moreover provide design principles to guide future manufacturing, use and disposal of plastics.

Viability of a circular economy for space debris.

The orbital debris population is rapidly growing, increasing the chance of a Kessler-style collision event. We report a novel method for the production of estimates for the total monetary value of all debris objects and total mass of all objects currently in orbit. The method was devised using debris object data from the European Space Agency's DISCOS dataset, classified via a decision tree. 'Reuse' and 'scrap material' scenarios were developed. A high-end estimate for reuse shows a net value of $1.2 trillion. Median and low-end net value estimates of $600 billion and $570 billion, respectively, are probably judicious. A scrap material scenario produced a high mass estimate of 19,124 tonnes, a median of 6,978 tonnes and a low estimate of 5,312 tonnes. Development of in-orbit services will be crucial to solve the orbital debris problem. A future circular economy for space may be financially viable, with potentially beneficial consequences for risk reduction; resource efficiency; additional high-value employment; and climate-change knowledge, science, monitoring and early warning data.

Tea Bags for Fmoc Solid-Phase Peptide Synthesis: An Example of Circular Economy.

Peptide synthesis is an area with a wide field of application, from biomedicine to nanotechnology, that offers the option of simultaneously synthesizing a large number of sequences for the purpose of preliminary screening, which is a powerful tool. Nevertheless, standard protocols generate large volumes of solvent waste. Here, we present a protocol for the multiple Fmoc solid-phase peptide synthesis in tea bags, where reagent recycling steps are included. Fifty-two peptides with wide amino acid composition and seven to twenty amino acid residues in length were synthesized in less than three weeks. A clustering analysis was performed, grouping the peptides by physicochemical features. Although a relationship between the overall yield and the physicochemical features of the sequences was not established, the process showed good performance despite sequence diversity. The recycling system allowed to reduce N, N-dimethylformamide usage by 25-30% and reduce the deprotection reagent usage by 50%. This protocol has been optimized for the simultaneous synthesis of a large number of peptide sequences. Additionally, a reagent recycling system was included in the procedure, which turns the process into a framework of circular economy, without affecting the quality of the products obtained.

Study on the influence of advanced treatment processes on the surface properties of polylactic acid for a bio-based circular economy for plastics.

New biotechnological processes using microorganisms and/or enzymes to convert carbonaceous resources, either biomass or depolymerized plastics into a broad range of different bioproducts are recognized for their high potential for reduced energy consumption and reduced GHG emissions. However, the hydrophobicity, high molecular weight, chemical and structural composition of most of them hinders their biodegradation. A solution to reduce the impact of non-biodegradable polymers spread in the environment would be to make them biodegradable. Different approaches are evaluated for enhancing their biodegradation. The aim of this work is to develop and optimize the ultrasonication (US) and UV photodegradation and their combination as well as dielectric barrier discharge (DBD) plasma as pre-treatment technologies, which change surface properties and enhance the biodegradation of plastic by surface oxidation and thus helping bacteria to dock on them. Polylactic acid (PLA) has been chosen as a model polymer to investigate its surface degradation by US, UV, and DBD plasma using surface characterization methods like X-ray Photoelectron Spectroscopy (XPS) and Confocal Laser Microscopy (CLSM), Atomic Force Microscopy (AFM) as well as FT-IR and drop contour analysis. Both US and UV affect the surface properties substantially by eliminating the oxygen content of the polymer but in a different way, while plasma oxidizes the surface.

Microbiology challenges and opportunities in the circular economy.

Our knowledge and understanding of micro-organisms have led to the development of safe food, clean water, novel foods, antibiotics, vaccines, healthier plants, animals and soils, and more, which feeds into the United Nations Sustainable Development Goals (UN SDGs). The circular economy can contribute to the UN SDGs and micro-organisms are central to circular nutrient cycles. The circular economy as described by the Ellen MacArthur foundation has two halves, i.e. technical and biological. On the technical side, non-biological resources enter manufacturing paths where resource efficiency, renewable energy and design extend the life of materials so that they are more easily reused and recycled. Biological resources exist on the other half of the circular economy. These are used to manufacture products such as bioplastics and paper. The conservation of nature's stocks, resource efficiency and recycling of materials are key facets of the biological half of the circular economy. Microbes play a critical role in both the biological and technical parts of the circular economy. Microbes are key to a functioning circular economy, where natural resources, including biological wastes, are converted by microbes into products of value and use for society, e.g. biogas, bioethanol, bioplastics, building block chemicals and compost for healthy soils. In more recent times, microbes have also been seen as part of the tool kit in the technical side of the circular economy, where microbial enzymes can degrade plastics and microbes can convert those monomers to value-added products.

Plastics and sustainable purchase decisions in a circular economy: The case of Dutch food industry.

Every day, society's concern over pollution caused by plastic waste grows greater. One of the most intensive sectors for the use of plastic is the food industry. Companies in this sector face the challenge of transitioning to a more sustainable and less intensive model of plastic use, respecting the principles established for a circular economy. Accordingly, one of the questions that industries tend to ask is whether sustainability will influence the consumer's purchase decision. To respond to this, the factors that determine a consumer's sustainable purchase decision in relation to the plastic and food industry have been analyzed in this paper. For this, a regression analysis was performed on a sample of Dutch consumers. The results show that the decision of purchase of the consumer of the Food Industry is conditioned by factors such as age, sustainable behavior, knowledge of the Circular economy and the perception of usefulness of plastic.

Sustainable financing for municipal solid waste management in Nepal.

Financing municipal solid waste (MSW) services is one of the key challenges faced by cities in developing countries. This study used plastic waste, a constituent of MSW, to explore the possibility of generating revenue for financing MSW management in the municipalities of Nepal. The results of this study suggest that plastic material recovery could generate revenue, which is equivalent to 1.38 times of the plastic-waste-related management cost when collection efficiency reaches 66.7%. An increase in 1% of recovery rate and collection efficiency could cover an additional 4.64% and 2.06% of the costs of managing plastic waste, respectively. In addition, an increase in tax on imported plastic materials could also motivate recovery of plastic waste for recycle and reuse. An additional 1% tax on plastic imports would be sufficient to cover plastic-related waste management when plastic waste recovery and collection efficiency rates are low. This plastic recovery- revenue exercise could be expanded to other materials such as paper and metal to fully understand the possibility of sustainable financing of MSW management and reducing environmental harm in developing countries like Nepal.

Incentive Mechanism and Subsidy Design for Construction and Demolition Waste Recycling under Information Asymmetry with Reciprocal Behaviors.

To solve information asymmetry, we adopted the principal-agent framework to design the incentive mechanisms between the remanufacturer and the collector in the construction and demolition (C&D) waste-recycling industry. By using the model of reciprocity, we analyzed how the entities' behavioral motives affect their decisions in terms of the incentive mechanisms. The findings showed that the collector responds to their perception of the remanufacturer's intentions. If the perception is positive, they will make more effort in the collection work. If not, less effort will be put forth. Most importantly, we found that reciprocity helps to save the remanufacturer cost in the incentive mechanisms and makes the collector choose a higher effort level in the collection work. This finding showed that reciprocity serves to solve information asymmetry. By conducting a numerical simulation, we found that although a high subsidy policy can achieve rapid improvement of recycling-supply-chain performance, it is inefficient in maintaining friendly cooperation between the remanufacturer and the collector.

Quantitative analysis of eco-economic benefits of reclaimed water for controlling urban dust.

With the acceleration of urbanization and industrialization, urban air pollution, especially dust pollution, has become a global problem. The traditional method to control dust problem is to spray roads with tap water. However, this method will inevitably lead to a huge waste of water resources. Using reclaimed water instead of tap water for dust control can not only achieve the same effect of reducing dust and haze, but also save water resources. In addition, the saved tap water can be used for production and life, thereby obtaining additional benefits. In order to quantify the eco-economic benefits of sprinkling water for dust control, a quantitative method was proposed based on the emergy theory of ecological economics. It was used to calculate the cost of different water resources, the cooling and humidifying benefit, the dust control and haze reduction benefit, and the other use benefit. Taking the 2017 data of Zhengzhou as an example, the results indicated that the cost of using reclaimed water to control dust was reduced by 54%. The total benefit of using reclaimed water was about 1.30-1.80 times that of using tap water, and the net benefit was 4.65-7.17 times. Therefore, the use of reclaimed water instead of tap water for road dust control has advantages of low cost and high eco-economic benefits. The method proposed in this paper can provide quantitative basis for the popularization of using reclaimed water to dust control in cities with serious air pollution and water resource shortage.