Waste Management & Research最新文献

The method based on machine learning and laser-induced breakdown spectroscopy (LIBS) is effective for rapid characterization of waste organic polymers (WOP). However, the lack of mechanistic interpretability leads to raises concerns regarding its reliability in practical applications. This study systematically investigated the fundamental chemical correlations between WOP fuel properties and LIBS spectral features through feature selection and machine learning interpretability analysis. Thirteen radical-associated key peaks were selected and strategically categorized into two groups for model construction. Under optimal conditions, the prediction accuracy for carbon, hydrogen, oxygen content and lower heating value (LHV) reach 97.74%, 91.22%, 91.28% and 97.02%, respectively. Notably, models utilizing 10 selected key peaks demonstrated superior performance compared to those employing raw LIBS spectra or principal components, especially with the absolute difference reaching 14.57% for O content prediction. Interpretability analysis showed that C2 swan bands had highest effects impacts on carbon, oxygen content and LHV prediction, whereas H I line was essential for hydrogen content prediction. This mechanistic investigation provided theoretical validation for LIBS-based rapid characterization systems, facilitating their practical implementation in downstream energy recovery processes. The established methodology offers a scientific foundation for advancing sustainable waste management and promoting circular economy development through efficient resource utilization.

The growing interest in recovering resources from old dumpsites has greatly accelerated the adoption of landfill mining (LFM) in recent years. This study focuses on assessing the quality of materials recovered from diverse legacy waste dumpsites using a strata-based approach. The method involved waste characterization, elemental analysis, physico-chemical characterization, heavy metals analysis and correlation analysis to assess the potential of solid waste samples collected from all three layers. Results revealed intriguing patterns in waste composition, with an increase in soil like fractions with depth and percentage of single-use plastic was almost same in all layers. Elemental analysis revealed variations in nitrogen, carbon, hydrogen and sulphur content across different layers, showcasing the heterogeneity of legacy. There was a small variation in the percentage of carbon in the first two layers, indicating high potential for use as fuel in the form of refuse-derived fuels. Significant changes were observed in layer 3, indicating it is best suited for landfill gas collection. Similar trends were observed for other elements. The presence of nitrogen-rich content indicates the potential for ammonia production, whereas hydrogen-rich materials suggest the possibility of generating hydrogen gas. Sulphur-rich waste holds promise for contributing to sulphur dioxide production. Correlation analysis was performed to maximize resource recovery while minimizing environmental risks.

Introducing flexible biogas production (FB) can result in instantaneous high-shock loads for anaerobic digestion system, posing risks to the system's stable operation. Steel slag, a typical metallurgical solid waste, has been demonstrated to enhance the buffering capacity of digestion systems, thereby increasing methane production and achieving 'waste treatment using waste'. However, its efficacy under high-shock loads in FB is uncertain. Pulse feeding experiments simulating FB were conducted to analyse the system's impact resistance with steel slag addition and investigate its enhancement mechanisms. The addition of steel slag improved the methane production rate under various shock conditions, with a particularly notable enhancement under concentration shock. This scenario also saw a significant increase in the generation of soluble chemical oxygen demand and its utilization by microorganisms. This can be attributed to the enrichment of hydrolytic bacterial phyla (Firmicutes) and genera (Gelria), with functional gene analysis revealing an increase in genes associated with Fe(III) reduction and CO₂-to-methane pathways. The study results indicate that the role of steel slag as an alkaline, iron-rich material enhances system alkalinity, reduces inhibition from H₂ partial pressure and boosts hydrogenotrophic methanogen activity, making it suitable as an exogenous enhancer for demand-oriented anaerobic digestion.

Compostable packaging may provide a more sustainable alternative to conventional packaging. However, people often inappropriately dispose of compostable packaging which limits its potential benefits. This study applied the Behaviour Change Wheel and the capability, opportunity, motivation-behaviour model to develop and evaluate the effect of a behaviour change intervention on the disposal of compostable packaging at workplaces. Focus groups, observations, analysis of existing materials and a review of the literature identified barriers in relation to capability, opportunity and motivation to compost packaging. The intervention addressed the identified barriers through clear and distinctive labels on packaging, matching bin signage, a motivational video and an onboarding presentation for workplaces. The intervention was implemented in three workplaces and evaluated using a pre-post design. The intervention led to sustained increases in compostable packaging in compostable bins and reduced contamination. A post-intervention survey and roundtable event suggested that the intervention was acceptable to workplace leads and employees. There was no evidence that the intervention changed perceived capability, opportunity and/or motivation. The main recommendations for packaging producers and workplaces include using consistent distinctive bin signage that corresponds with standardized packaging labels.

Waste recycling heralds a vital agenda in the circular economy (CE) to leverage emission reduction targets. However, the role of digitalization in waste management (WM) is underexplored, and the literature remains fragmented. This study explores the synergy between CE principles in tourism and decarbonization in the waste sector through digitalization, using case studies from Taipei (Republic of China) and Sukunan (Indonesia). By examining the integration of digital tools in WM systems, the study highlights how these cities leverage technology to promote net-zero emissions and sustainable practices, particularly in the context of tourism. The research employs a mixed-methods approach, combining qualitative data from focus group discussions, semi-structured interviews and secondary data analysis. The findings reveal that digitalization has significantly improved WM efficiency, resource recovery (RR) and carbon footprint reduction in both study areas. Notably, the study demonstrates that tourism plays a role in driving these digitalization efforts, particularly through the adoption of CE practices in WM. The results suggest that digital solutions, when tailored to local contexts, can accelerate decarbonization and enhance sustainability. In Sukunan, technological adoption generated 780 new jobs and raised average household incomes by USD 45 monthly. These initiatives reduced landfill waste by 30% and cut CO₂-equivalent emissions by about 0.3 million metric tonnes annually. Taiwan's 'Pay-As-You-Throw' (PAYT) system is a benchmark, showcasing effective WM and resource recovery practices. Digitalization is projected to trim WM costs by 35%, reduce annual expenses by 3.6%, generate USD 493 billion in revenue over decades and subdue global CO₂ emissions by 15% by 2030. Overall, this work emphasizes the potential for replicating such strategies in other cities, with consideration for local conditions, to achieve sustainability and decarbonization goals in the tourism and WM sectors.

The growing number of mobile phone users on a global scale has led to enormous amounts of electronic waste (e-waste) being generated annually. Insufficient knowledge of e-waste separation causes individuals to dispose of e-waste along with other waste. As a result, this cannot be used in the recycling process. The aim of this study is to determine the elements that significantly impact the intention of mobile phone repairers to carry out separation of e-waste. The integrated model incorporates Self-Determination Theory (SDT) factors (viz., amotivation, external regulation, identified regulation, intrinsic motivation, introjected regulation and integrated regulation) and Institutional Theory (IT) factors (viz., coercive pressure, mimetic pressure and normative pressure). Empirical data were collected through a printed questionnaire survey, with a total of 198 valid respondents. Moreover, this research utilized a hybrid data analysis method, using partial least squares structural equation modelling and artificial neural network to assess the model. The findings of this study indicate that all the SDT and IT factors are supported, except coercive pressure. This research adds to the existing body of knowledge on e-waste separation by shedding light on the problem from the viewpoint of mobile phone repairers, offering useful information to governments and waste recycling companies to understand the intentions of repairers with respect to e-waste separation and formulate such strategies that can enhance the involvement of repairers in e-waste separation activities.

Biowaste is an increasingly relevant environmental issue worldwide, causing significant environmental, economic and social impacts. Effective strategies are crucial to mitigate impacts, maximising biowaste's valorisation. This article presents a systematic literature review on using life cycle assessment (LCA) to evaluate municipal biowaste treatment facilities. The primary objective was to analyse how LCA is applied to assess the environmental efficiency of mechanical and biological treatment involving composting and anaerobic digestion (AD)-based systems. The article addressed the methodological heterogeneity across previous LCA studies, identifying critical gaps and challenges regarding standardisation and result comparability. It underscores the importance of accurately considering environmental indicators and emission factors, as these significantly affect overall LCA outcomes. Results show that most publications focus on Europe and Asia, highlighting a research gap in regions like Africa. The organic fraction municipal solid waste is the predominant feedstock, and 1 tonne of biowaste was the frequently used functional unit, reflecting the upstream impacts of waste. The most recurrent system boundary was the cradle-to-grave, offering a comprehensive analysis as it covers all stages of biowaste treatment from collection to disposal. The studies highlight the environmental benefits of AD-based systems through energy production compensations, particularly in reducing global warming potential, compared with other treatment operations such as landfills. While replacing mineral fertilisers with digestate and compost is very well discussed, it raises concerns about heavy metal content and nutrient availability. Therefore, selective collection of organic waste is crucial to improve compost quality and AD efficiency, though it increases transportation costs.

The expanding pharmaceutical industry generates a large amount of waste salt (WS) with a complex composition, which is difficult to treat and poses potential risks to the environment and human health. Removing toxic organic compounds has become a bottleneck issue that needs to be addressed. This article presents a comprehensive review of traditional and emerging treatment technologies based on the sources and characteristics of WS from the pharmaceutical industry. It also discusses the problems and challenges faced by typical WS treatment technologies and evaluates the application of innovative integrated processes. Building on this, a future outlook for pharmaceutical WS treatment technologies is outlined. This review aims to assist scientists in enhancing their understanding of different technologies used for treating WS, thereby accelerating the improvement of process parameters and technologies.

Certified compostable packaging has the potential to be a more sustainable alternative to some conventional plastics, but only if disposed of appropriately. This study developed and evaluated the effects of a behaviour change intervention on the disposal of compostable packaging in the co-mingled food and garden waste bin for industrial composting in households in the United Kingdom. The intervention targeted barriers to the appropriate disposal of compostable packaging as identified via focus groups, previous research and the capability, opportunity, motivation-behaviour model. Intervention components included front- and back-of-pack labels, tips on positioning of household bins, visual reminders to check packaging labels and which bin to use, and a bag of compost with an infographic highlighting what happens during the composting process. The intervention was delivered over 6 weeks to 120 households who were provided with compostable and non-compostable items. The results from online surveys completed at three time points (pre-intervention, post-intervention and follow-up) and weekly waste audits that assessed the weight of compostable packaging in the food and garden waste bin showed significant increases in perceived capability, opportunity and motivation to correctly dispose of compostable packaging via the food and garden waste bin over the course of the intervention and increased amounts of compostable packaging disposed of. The implications are that standardised, clear labels on industrially compostable packaging are needed to help residents to identify and appropriately dispose of this packaging. Strategies that automatically prompt which bin to use and increase residents' awareness and motivation to appropriately dispose of compostable packaging are also recommended.

Promoting refurbished products can positively impact environmental performance and play a vital role in reducing waste. This study employs the concept of the theory of perceived risk to examine the influence of social and financial risk, online retail channels and return policy on consumer-perceived risk. Additionally, it proposes that an online retail channel with a lenient return policy may enhance the intention of consumers to purchase refurbished products. The hypotheses were examined using partial least square structural equation modelling. The findings suggest that social risk, return policy and financial risk significantly enhance the perceived risk of purchasing refurbished products, but the online retail channel does not substantially impact perceived risk, which may be if both online and offline channels provide the same level of support and policy. The results also indicate that perceived risk mediates consumers' online purchase intention for refurbished products. This study is distinctive because it analyses the effects of social and financial risk, return policy and retail channel on consumers' perceived risk when purchasing refurbished products online. This study examines the concepts of online purchasing of refurbished products, which have received limited attention in existing literature. While previous studies have looked at these concepts separately, we aim to provide a comprehensive analysis by studying them together. By implementing the findings of this study, businesses can contribute to the circular economy, conserve resources, potentially reduce environmental imprints and enhance sustainability performance.