Post-consumer plastic packaging waste flow analysis for Brazil: The challenges moving towards a circular economy

Enhancing circular plastic waste management: Reducing GHG emissions and increasing economic value in Rayong province, Thailand

This study evaluates the greenhouse gas (GHG) emissions and economic value creation of plastic waste (PW) management in Rayong, Thailand, a city on the eastern Gulf Coast with a significant amount of generated and leaked PW. By analyzing current practices, and developing and evaluating improvement scenarios, the study explores strategies for reducing GHG and enhancing economic benefits across the PW management chain. Four primary routes with varying capacities handle approximately 5,445.55 tonnes of PW via source separation recycling (5.18 %), post-sorting recycling (9.30 %), energy recovery (54.86 %), and landfills or opened dump disposal (30.66 %). About 83.21 % of the 16 ± 6.9 % PW in municipal solid waste (MSW) is recyclable, primarily consisting of high-density polyethylene (HDPE), polypropylene (PP), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and polyethylene terephthalate (PET). The current management practice generates an economic benefit of approximately 1.68 million USD/yr or 310 USD/t of PW, compared to the proposed scenarios, which enhances recycling efficiency and reduces landfill and energy recovery waste, yielding 2.27-6.48 million USD/yr or 420.64-1200.33 USD/t of PW. The practice emits about 7,028.47 tCO2e annually, while improved source and post-sorting efficiencies reduce GHG emissions by 2.86-3.17 times or -2.83 to -2.42 tCO2e/t of PW or a total of over 13,078.60-15,268.44 tCO2e. Burning PW increases approximately 1.6 times or 11,841.36 tCO2e/yr. Enhancing recycling efficiency, particularly through source separation, is key to promoting more productive and valuable PW separation, increasing economic value and GHG mitigation by approximately 3.87 and 3.17 times, respectively. These findings provide valuable insights for local authorities and policymakers to develop strategic interventions and policies that align with the improved scenario by enhancing source separation and recycling. The results demonstrate that improving the efficiency of separation at the source is critical for transitioning from a linear PW management strategy to a circular economy, significantly reducing landfill waste and mitigating environmental threats.

Characterisation of household single-use packaging flows through a municipal waste system: A material flow analysis for New South Wales, Australia

Household single-use packaging has poor rates of recycling, and presents a challenge in transitioning to a circular packaging economy. This study characterises the flows of household single-use packaging in the municipal waste system for 2020-21 in New South Wales, Australia. Households are an important source of packaging usage in Australia, accounting for over 40 % of all packaging used in 2020-21. Our focus spans 17 single-use packaging materials and 11 formats. We estimate the composition of single-use consumer packaging in the kerbside collection stream, and the ultimate fate of used packaging. Results show 1000 ± 8 % kt of packaging was used by households in NSW in 2020-21 (∼123 kg/cap). Composition of the used packaging stream was dominated by glass (36 %), paper (29 %) and plastic (28 %) packaging. HDPE (26 % of plastic packaging), LDPE (24 %) and PET (19 %) were the main polymers in use. 63 % ± 5 % of used packaging was collected for recycling, and 34 % ± 7 % was recovered via recyclate generation and overseas exports. Glass packaging had the highest recycling rates at 52 % ± 3 %, while plastic packaging had the poorest at 11 % ± 10 %. Findings indicate incorrect disposal of recyclables at the household to mixed-waste systems as a major limitation of the system to improve recycling rates. Expansion in recovery capacity is also essential for improving recycling rates, and the potential for generating the packaging-grade recyclate essential for meeting recycled content targets. The study offers contributions to the understanding of consumer packaging managed within the municipal waste system. Insights gained have application in informing sustainable packaging and waste management strategies.

Municipal solid waste management instruments that influence the use of the refuse as fuel in developing countries: A critical review

Landfills are the destination of most of the refuse generated whereas composting, material recycling, and Waste-to-Energy (WtE) technologies are not commonly employed in developing countries. However, the destination for energy purposes could be supplied with this refuse, improving the viability of energy use. Thus, this article raises some questions to identify aspects that could encourage its use as refuse-derived fuel (RDF) in these countries. Among them, does environmental education affect the municipal solid waste (MSW) source separation with emphasis on a destination? Can selective collection and extended producer responsibility (EPR) affect the MSW for energy recovery? Is there competition between the recycling market and the energy market for RDF? A systematic review of the literature was conducted to gather data and provide answers to such questions. This enabled to observe that EPR, selective collect expansion and source separation influence the quantity and quality of waste sent for energy use. Both internal and external factors impact on source separation. Additionally, there is evidence to support that despite several studies showing their technical, economic, environmental and social viability, the methods of energy usage of the refuse still need to improve their deployment in developing countries. In addition to identifying the main research gaps to be filled in future studies, the article also identified the instruments of MSW management that are to be applied in developing countries to divert recyclable and organic waste from landfill.

Characterization of Poly(3-hydroxybutyrate) (P3HB) from Alternative, Scalable (Waste) Feedstocks

Bioplastics hold significant promise in replacing conventional plastic materials, linked to various serious issues such as fossil resource consumption, microplastic formation, non-degradability, and limited end-of-life options. Among bioplastics, polyhydroxyalkanoates (PHA) emerge as an intriguing class, with poly(3-hydroxybutyrate) (P3HB) being the most utilized. The extensive application of P3HB encounters a challenge due to its high production costs, prompting the investigation of sustainable alternatives, including the utilization of waste and new production routes involving CO2 and CH4. This study provides a valuable comparison of two P3HBs synthesized through distinct routes: one via cyanobacteria (Synechocystis sp. PCC 6714) for photoautotrophic production and the other via methanotrophic bacteria (Methylocystis sp. GB 25) for chemoautotrophic growth. This research evaluates the thermal and mechanical properties, including the aging effect over 21 days, demonstrating that both P3HBs are comparable, exhibiting physical properties similar to standard P3HBs. The results highlight the promising potential of P3HBs obtained through alternative routes as biomaterials, thereby contributing to the transition toward more sustainable alternatives to fossil polymers.

Marine plastics, circular economy, and artificial intelligence: A comprehensive review of challenges, solutions, and policies

Global plastic production is rapidly increasing, resulting in significant amounts of plastic entering the marine environment. This makes marine litter one of the most critical environmental concerns. Determining the effects of this waste on marine animals, particularly endangered organisms, and the health of the oceans is now one of the top environmental priorities. This article reviews the sources of plastic production, its entry into the oceans and the food chain, the potential threat to aquatic animals and humans, the challenges of plastic waste in the oceans, the existing laws and regulations in this field, and strategies. Using conceptual models, this study looks at a circular economy framework for energy recovery from ocean plastic wastes. It does this by drawing on debates about AI-based systems for smart management. In the last sections of the present research, a novel soft sensor is designed for the prediction of accumulated ocean plastic waste based on social development features and the application of machine learning computations. Plus, the best scenario of ocean plastic waste management with a concentration on both energy consumption and greenhouse gas emissions is discussed using USEPA-WARM modeling. Finally, a circular economy concept and ocean plastic waste management policies are modeled based on the strategies of different countries. We deal with green chemistry and the replacement of plastics derived from fossil sources.

How natural and anthropogenic factors should drive microplastic behavior and fate: The scenario of Brazilian urban freshwater

Brazil maintains its position at the top of the global ranking of plastic producers, yet recycling efforts have been incipient. Recent data reveals an annual production of approximately 14 million tons of plastic waste, not accounting for the surge in the usage of plastic masks and related materials due to the COVID-19 pandemic. However, what remains largely unreported is that over half of post-consumer plastic packaging in Brazil is managed without any monitoring, and it remains unclear how this will contribute to the occurrence of plastic waste and microplastics in Brazilian freshwaters. This scenario requires the consideration of several other crucial factors. Studies have been carried out mainly in marine and estuarine waters, while data on freshwaters are lacking. Brazil has continental dimensions and the highest water availability on the planet, yet the demand for water is greatest in regions with medium to low supply. Many densely populated Brazilian urban areas face chronic flood problems, possess inadequate levels of wastewater treatment, and display inadequate solid waste management practices. Consequently, urban freshwater with tropical characteristics in Brazil presents an intriguing scenario and is complementary to the most commonly studied marine environments. In this study, we explore the nuances of pollution in Brazilian urban freshwater and discuss how various parameters, such as organic matter, suspended solids, temperature, and pH, among others, influence the behavior of microplastics and their interactions with organic and inorganic contaminants. Furthermore, we address how microplastic conditions, such as biofouling, the type of plastic, or degradation level, may impact their behavior. By analyzing how these conditions change, we propose priority themes for investigating the occurrence of microplastics in Brazilian urban freshwater systems under different degrees of human impact. Ultimately, this study aims to establish a network dedicated to standardized monitoring of microplastic pollution in Brazilian urban freshwaters.

Circularity in waste management: a research proposal to achieve the 2030 Agenda

Waste management is the main challenge in the transition away from the linear "take-make-dispose" economy. Incorporating the principles of circularity in waste management would facilitate the achievement of Sustainable Development Goals. This paper aims to provide state-of-the-art research about circular waste management in the fulfillment of the 2030 Agenda. For this purpose, bibliometric analysis by VOSviewer and SciMat software is used to define the evolution and to detect research trends. Based on the main gaps identified in studies, a research agenda to guide for further opportunities in this field is suggested. The results obtained four clusters that address sustainable industrial infrastructure, biological waste management, recycling in developing countries and recovery processes. Four research propositions are established, focusing on plastic waste management and generation trends, circular municipal waste management, more sustainable landfill management, and enablers such as indicators and legislation. The transformation towards more bio and ecological models requires social, regulatory and organizational tools that consider the best interests and capacity of companies, public authorities and consumers. In addition, policy implications are considered.

Insights into the Titania (TiO2) Photocatalysis on the Removal of Phthalic Acid Esters (PAEs) in Water

In this era of globalization, plastic is regarded as one of the most versatile innovations, finding its uses ranging from packaging, automotive, agriculture, and construction to the medical and pharmaceutical industries. Unfortunately, the single-use nature of plastics leads to ecological and environmental problems. Among conventional disposal management of plastic waste are landfilling dumping, incineration, and recycling. However, not all plastic waste goes into disposal management and ends up accumulating in lakes, rivers, and seas. In the aquatic environment, the action of photochemical weathering plastics has resulted in the release of chemical additives such as phthalic acid esters (PAEs), an important plasticizer added to plastic products to improve their softness, flexibility, and durability. Nowadays, PAEs have been ubiquitously detected in our environment and numerous organisms are exposed to PAEs to some extent. As PAEs carry endocrine disruptive and carcinogenicity properties, an urgent search for the development of an efficient and effective method to remove PAEs from the environment is needed. As a viable option, titania (TiO2) photocatalysis is a promising tool to combat the PAEs contamination in our environment owing to its high photocatalytic activity, cost-effectiveness, and its ability to totally mineralize PAEs into carbon dioxide and water. Hence, this paper aims to highlight the concerning issue of the contamination of PAEs in our aquatic environments and the summary of the removal of PAEs by TiO2 photocatalysis. This review concerning the significance of knowledge on environmental PAEs would hopefully spark huge interest and future development to tackle this plastic-associated pollutant. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

Retrospective and prospective material flow analysis of the post-consumer plastic packaging waste management system in Flanders

The post-consumer plastic packaging waste management in Flanders was analyzed by performing a retrospective material flow analysis, covering an extensive period from 1985 to 2019. In addition, a prospective material flow analysis of 32 improvement scenarios was performed, based on expected changes in the waste management system. Mass recovery rates were calculated based on different interpretations of the calculation rules. Moreover, various cascading levels were identified to differentiate between the quality level of the secondary applications. The mass recovery rate including only recycling evolved from a value of 0% in 1985 to 31% in 2019 and could be increased to 36-62% depending on the improvement scenario selected. However, the different interpretations of the calculation rules led to a variation of up to 20 and 41% on this mass recovery rates for the retrospective and prospective analysis, respectively. The introduction of monostream recycling for additional post-consumer plastic packaging flows, such as low-density polyethylene, did not lead to increasing mass recovery rates, if no differentiation for the cascading levels was made. The Belgian recycling target of 65% for 2023 will be challenging if the strictest calculation method needs to be followed or if the improvements in the Flemish post-consumer plastic packaging waste system do not follow the best-case collection scenarios under the given assumptions. To harmonize the calculation and monitoring of these targets, clear calculation rules need to be accompanied with a harmonized monitoring system over the entire waste management system.

Effect of corn stigma extract on physical and antioxidant properties of biodegradable and edible gelatin and corn starch films

The development of bio-based food packaging with antioxidant properties is an important research topic and has gained prominence these days. In this study, bioactive films were developed based gelatin-corn starch (GCS) incorporated with corn stigma extract (CSE) at different concentrations (15% and 25%; w/v). In preliminary tests, the extract maintained cell viability above 90% indicating that it is safe for application as an active ingredient. Insertion of the extract did not influence the thickness of the films but caused a slight change in optical properties. Scanning electron microscopy (SEM) analysis revealed interactions between the extract's bioactive compounds with gelatin and corn starch compounds, which may have improved the mechanical properties (elongation at break, Young's modulus). The addition of 25% corn stigma extract increased the contact angle, giving the film a hydrophobic character. Furthermore, at this concentration, a 15% reduction in water vapor permeability was observed. The elaborated films showed complete biodegradability before the tenth day of the study. It can be inferred that the films with corn stigma extract have good antioxidant properties, indicating that they can be used as an ingredient for food packaging.

Management of Plastic Waste and a Circular Economy at the End of the Supply Chain: A Systematic Literature Review

This article aims to describe the current state of research on plastic waste management as a circular economy practice at the end of the supply chain. The methodological strategy chosen was a systematic literature review. The articles selected from the Web of Science and Scopus databases were screened, and the research corpus consisted of 201 articles published in journals between 2014 and 2021. The results present 13 study categories, showing topics such as pyrolysis, business models, Industry 4.0, and energy generation. The insertion of Industry 4.0 technologies is still in its initial stages, comprising mainly the generation of inputs to reuse waste for 3D printers’ materials. Regarding energy generation, the insertion of processes such as pyrolysis for fuel generation stands out. The proposed discussion in this article suggests a circular ecosystem in which wastes follow a reuse flow according to their properties; incineration can be an option depending on the stage and benefits generated from the removal of plastic waste from the ecosystem. The highlighted issue is the scalability of the developed processes in the research, which is only possible if the state, universities, and civil society integrate efforts in the construction of a circular ecosystem infrastructure for waste management.

Circular Economy and Central Bank Digital Currency

The emergence of central bank digital currency (CBDC) provides an opportunity for central banks to make an important contribution to the transition to a circular economy. This paper examines the role of a central bank digital currency in the circular economy. Central banks can contribute to the transition to a circular economy in two ways: first, by making central bank digital currency accessible to circular businesses and other players in the circular economy sector, and second, by looking into how the design features of CBDC can support circular economy goals. On the role of CBDC in the circular economy, I argue that a central bank digital currency offers a better payment option for circular economy financial transactions; central bank digital currency can lead to greater financial inclusion for 'unbanked' informal workers in the circular economy; CBDC can create a gateway that allows a central bank to offer financial assistance to distressed circular businesses; using a central bank digital currency can reduce illicit activities in the circular economy; a central bank digital currency can be used to provide stimulus funding to support circular businesses during crises; and, a central bank digital currency can offer low transaction cost for circular economy financial transactions. The paper also shows the link between CBDC and the circular economy. It also offers a critical perspective on the link between CBDC and the 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.

Simulating the Effect of Mixed Subsidy Policies on Urban Low-Value Recyclable Waste in China: A System Dynamics Approach

Low-value recyclable waste accounts for a large portion of urban waste output in many modern cities. The improper management and disposal of LVRW result in environmental pollution and a waste of resources. Given the characteristics of a high recovery cost and low recovery income of low-value recyclables, it is difficult to obtain a satisfactory waste disposal effect by completely relying on the market mechanism. It is thus necessary for the government to implement effective subsidies for multiple subjects in the urban waste recycling system (UWRS). This study examines the independent roles of four subsidy policies-subsidy to the third-party waste disposal institutions, subsidy to a state-owned waste disposal institution, R&D subsidy for green technology, and subsidy for government publicity-and develops a system dynamics model to verify the performance of the UWRS under different combinations of subsidy-based policies under multiple scenarios. Data on urban waste disposal for Guangzhou from 2019 and 2020 were used to validate and simulate the model. A sensitivity analysis of the main exogenous variables was carried out, and the conclusions are as follows: (1) On the premise of a fixed subsidy capital pool, a mixed subsidy policy produced the best impact on the UWRS. (2) The total subsidy needed to reach a certain threshold; otherwise, the mixed subsidy policy did not improve the UWRS. The total subsidy produced diminishing returns once it had exceeded the threshold. (3) Appropriately reducing subsidies for the third-party waste disposal institutions within a reasonable range does not affect the performance of the UWRS. (4) The effect of government publicity has short-term advantages, while the long-term potential of green technology is greater. Multi-agent coordination and the guidance of the market mechanism are important priorities in the design of subsidy-based policies. In addition, the trade-off between subjects needs attention, and a plan for mixed subsidy policies needs to be designed and implemented according to the response periods of different policies. The research here provides theoretical support for the government for designing subsidy-based policies.