Resources, conservation & recycling advances最新文献

This research aims to investigate the factors that influence green behavior in two developing countries, Malaysia and Nigeria. The study is based on the theory of planned behavior (TPB) and reasoned action (TRA), and it includes additional factors such as green culture, green product trust, product value, price sensitivity, and environmental awareness. A total of 547 participants were surveyed using a quantitative approach. The results from the multi-group (MGA) and partial least squares-structural equation modeling (PLS-SEM) analyses indicated that the extended TPB/TRA model is valid in the chosen developing nations. The multi-country model shows a significant difference, especially in the path connecting attitude and price sensitivity towards green behavior. Consumers in both countries have a positive attitude towards environmental protection and exhibit a green culture towards eco-friendly practices. In both models, green product trust and value have a positive relationship with green behavior, but not with environmental awareness. Perceived behavioral control is positively linked to green behavior in Nigeria, but not in Malaysia. Green culture is the strongest predictor of green behavior, more so than attitude. These stimulus factors were stronger in Nigeria. In both countries, the relationship between green culture, price sensitivity, perceived behavioral control, and green behavior is mediated by attitude. The study suggests that consumers in the chosen developing nations are gradually embracing eco-friendly practices. The findings highlight the importance of promoting environmental awareness to encourage green behavior towards nature. The study further discusses the implications of these findings.

Food and other bio-waste management is an integral part of urban development and living. Composting is a common practice in most developed countries, while open burning and landfilling is widely used in waste management in low and middle income countries. The outputs of composting include compost, heat, leachate, and off-gas. The off-gas consists of carbon dioxide (CO2), methane, nitrous oxide, water vapor, ammonia and volatile organic compounds. The CO₂, although biogenic could contribute to climate change mitigation if the emissions are controlled. CO₂ sequestration using microalgae has been widely reported has been widely reported as a viable alternative to geological storage. CO₂ sources in microalgal cultivation include ambient air, composting off-gas, combustion flue gas, wastewater aeration gas, syngas, and biogas. Carbon dioxide from composting can be used in controlled environment agriculture instead of commercially produced alternative, or from ambient air. This review examines the available information on composting off-gas dynamics, particularly CO₂ evolution, and the challenges and prospects of CO₂ use in microalgal cultivation, ensuring circularity in the composting process. This review recommends the utilization of CO₂ from composting as alternative to direct air extraction. However, achieving higher CO₂ concentration relative to oxygen is challenging. While efforts are made towards reduction in greenhouse gas emissions during composting, near zero oxygen concentration in the off-gas is essential to enhancing CO₂ utilization in microalgae cultivation. This should be achieved without compromising compost quality such as germination index and chemical oxygen demand/heavy metals reduction efficiency.

The increasing growth of solar photovoltaic (PV) deployment raises end-of-life management concerns. Previous studies have forecasted PV waste; however, the implications of the regulations were not assessed. The present study estimates the volume and composition of end-of-life solar PV waste for the European Union and the United States. The recycling potential of generated waste and the fate of materials in end-of-life PV waste as per the present regulations is also estimated. Further, the work analyses solar manufacturers contributing to the waste and provides recommendations for improving solar PV waste management. The analysis in the present study shows that 24.93 million tonnes and 36.23 million tonnes (metric ton) of PV waste with an economic value of 189 billion USD and 262 billion USD are expected to be generated between 2025 and 2050 in the US and European Union, respectively. This work also indicates that the US lacks federal PV waste-specific management regulations and has different requirements across the states. In contrast, European countries have adopted the Waste Electrical and Electronic Equipment Directive in their national legislations in addition to country-specific PV manufacturer compliance schemes. Due to the lack of regulations, 20 MT of PV waste is expected to be disposed of in landfills in the US. Chinese manufacturers like Tongwei, Aiko, and LONGi are leading manufacturers of PV shipments globally. They could play a significant role in PV recycling and management if they adopt take-back programs and invest in recycling, contributing to future end-of-life PV waste management. In light of these observations, a need for greater synchronization between federal and state-level end-of-life PV regulations, collaboration among recyclers and PV industry stakeholders, and continued research and knowledge sharing is recommended. Secondly, incorporating emerging contaminants in PV waste regulations and waste characterization methods is required for responsible recycling and safe management.

Plastic pollution is a serious issue of global concern which requires an urgent and international response involving all relevant actors at different levels of the supply chain. Increasing production of single use plastics and the mismanagement of the resulting plastic packaging waste is one of the prominent reasons for this pressing environmental issue. Several potentially promising solutions, such as reusable, recyclable and compostable packaging systems exist. Many of these innovative approaches may contribute to achieving a circular plastic economy, but there is a need to categorise and collate these under unifying themes to facilitate the assessment and comparison of different strategies.

The aim of this research is to analyse and categorise the existing solutions that tackle the plastic packaging waste problem to identify the archetypes of these solutions. Literature and business practice reviews were conducted to discover existing solutions. 200 solutions were selected and categorised by exploring the common patterns. Finally, 10 archetypes and 17 sub-archetypes were introduced. These archetypes are: refill stations, mobile refill stations, refill at home solutions, prefilled packaging systems, reusable takeaway and delivery solutions, B2B reusable packages, packaging solutions led by elimination, compostable and biodegradable packaging, substitution to a non-plastic material and plastic recycling. The findings led to the development of an upstream packaging strategies framework. This paper makes an original contribution to knowledge with the development of this framework as a systematic way to map existing (and new) solutions that can potentially tackle the plastic packaging waste and pollution problem.

End-of-life vehicle (ELV) plastics pose technical challenges in conventional recycling due to their diverse polymer compositions. Consequently, landfilling remains the prevailing disposal method. This study explores an innovative approach by upcycling ELV plastics as a substitute for natural sand in concrete. The study investigates the physical, mechanical and economic performance of ELV plastic-containing concrete. Plastic aggregates were prepared from real-world ELV plastics, featuring particle sizes below 4.75 mm, with over 90 % falling within the range of 1.18–4.75 mm. The research involves replacing natural sand with ELV plastics at varying volumes (0 %, 15 %, 25 %, 35 %, and 40 %) and examines the effect of sand replacement on various concrete properties. The results suggest that as the replacement ratio increases, the workability, density, and strength of concrete decrease. However, the 28-day compressive strength of concrete at the maximum replacement rate of 40 % was found to be 39 MPa, which suffices for certain non-structural strength applications, such as traffic routes, shared-use paths, local streets and curbs. In addition, compared to previous studies using mixed commodity plastics, ELV plastics lead to significantly lower strength reductions at high replacement ratios. Scanning Electron Microscopy (SEM) analysis reveals a distinctive rough and fibrous aggregate morphology, which enhances physical binding and provides bridging effects within the concrete matrix, potentially mitigating strength loss. Moreover, the economic analysis highlights a significant potential to commercialize ELV plastics for concrete applications. This study demonstrates that ELV plastics can be effectively used at high replacement rates (up to 40 % by volume) in non-structural applications.

Hospitals generate large amounts of waste, part of which is recyclable. However, research shows that recycling opportunities in hospitals often get missed with human behaviour playing an important role. Following current behavioural science, better understanding the influences on hospital recycling behaviour can support the design of promising behaviour change interventions, which draw on identified facilitators and help overcome identified barriers, to maximise recycling potential. Therefore, this systematic review aimed to investigate the barriers and facilitators to hospital waste recycling.

Three databases were searched to identify studies in high-income countries, pertaining to barriers and facilitators to hospital waste recycling. Their findings were thematically analysed and narratively synthesised drawing on a combination of the Capability, Opportunity, Motivation – Behaviour (COM-B) model with a multi-level framework.

Twenty-four studies met pre-defined inclusion criteria. Reported influences on hospital waste recycling pertained to factors beyond the hospital environment (e.g. product design preventing recycling), the internal hospital environment (e.g. lack of access to recycling bins) and individuals working within hospitals (e.g. concerns about infection control). Most influences were located in the internal hospital environment. Many related to the physical opportunity of recycling behaviour, with the most dominant barriers being difficulties accessing appropriate recycling bins and lack of information or education on recycling.

This overview of barriers and facilitators to hospital waste recycling will aid researchers and practitioners in designing hospital waste recycling interventions addressing key identified influences. Combining the COM-B model with a multi-level framework allowed for identified influences to be organised in a nuanced manner.

Circular economy (CE) processes, such as reuse, remanufacturing, and recycling, play a significant role in reducing the environmental impacts of modern manufacturing industries. However, electric and electronic equipment (EEE) is still often designed to function for a short usable life after which it is discarded. Furthermore, the current relatively low price and high availability of virgin raw materials, compared to those of recycled materials, decrease the financial viability of recycling. This study conducts a systematic literature review on product design-related issues in the CE of EEE and induces a novel model of product design considerations for the CE of EEE. The aim is to identify design traits that are hindering the CE of EEE and what measures can be taken in the product development phase to create EEE compatible with CE. This study points out general issues in the disassemblability and recyclability of EEE, as well as a recurring theme of conflicting design needs between different CE processes. Furthermore, the minimum entropy product design priority model is introduced as the novel contribution of this study to highlight the dependency between technological maturity, expected product lifespan, and suitable CE processes.

This study expands the STIRPAT framework and utilizes mechanistic analysis and spatiotemporal heterogeneity analysis to examine the impact of market integration on carbon emission intensity and heterogeneity in East China. The findings reveal that market integrations play a significant role in reducing carbon emission intensity, and tax environment, urbanization, and consumption power prove to be important mechanism factors. The average treatment effect of industrial structure and energy structure also positively promotes emission reduction efforts. However, market integration coupling coordination degree, technology level, and the gap in high-quality development act as inhibiting factors on carbon emission intensity. Furthermore, the spatial and temporal heterogeneous evolution trend demonstrates distinct and evident agglomeration patterns among economic regions. To effectively leverage the unified large market mechanism to reduce carbon emission intensity, it is essential to consider the regional characteristics of different influencing factors and also focus on the role of important node cities in driving emission reduction efforts.

Polyhydroxyalkanoates (PHAs) are polymers synthesized by diverse bacteria for carbon and energy storage applications. PHAs are biodegradable and nontoxic. They also exhibit properties similar to those of petroleum-based polymers. Therefore, these materials are promising alternatives to conventional plastics. This review aims to provide a comprehensive overview of PHA research, from production to application. This review summarizes the thermal and mechanical properties of various PHA homopolymers and copolymers, and compares them with those of common petroleum-based polymers. This comparison indicates that elongation at break is a major weakness of many PHAs. Different organic wastes used in PHA microbial production by mixed culture fermentation are summarized in this review. Important parameters of feedstock fermentation, culture selection, and PHA accumulation were compared. The pH and organic loading rate significantly affected the overall PHA yield, and various feedstocks led to different PHA compositions. Physical (blending and fiber reinforcement) and biological (cofeeding) modifications to improve the mechanical properties of PHA are elaborated in this review. Tensile properties are the major improvements among the mechanical properties after modification. Current applications of PHA and its derivatives are also presented in this work. They are primarily applied in the medicine, agriculture, and packaging industries. The widespread application of PHA faces challenges such as high production costs and limited mechanical properties. This study intends to stimulate further research into cost-effective methods for PHA production and to explore additional modification techniques.

Government is often seen as the arbiter for environmental protection. Alternatively, firms can volunteer to proactively take collective action toward sustainability, called industry self-regulation. But, what happens when neither of the two alternatives can deliver the expected outcomes? This inductive study addresses such a situation in managing hazardous consumer waste in the province of Ontario, Canada, where waste management and later circular economy have been on the agenda since the 1980s. However, both self- and government regulation failed to spur the advancements required to close material loops effectively and efficiently. Finally, after three decades, actors developed a new path to transition to circular economy. This longitudinal process study focuses on this process to explore the changes in business-policy interactions that realized this transition. I analyze extensive qualitative data, including 55 interviews with top-level decision-makers in all stakeholder groups (businesses, policy-makers, NGOs, consultants, etc.). Based on the unearthed patterns, I propose a hybrid model for regulation. In this model, both business and government coordinate throughout the process to set the rules and enforce them. By allowing organically shaped competition, this model can spur proactivity and innovation, which are crucial for the transition to circular economy but are hard to incentivize in conventional policy-making. The model can be used in any situation where an urgent issue needs immediate proactive responses by business.