Waste Management & Research最新文献

The implementation of ecological compensation for cross-regional domestic waste treatment is beneficial for balancing the interests of waste generation districts and waste treatment districts. This paper introduces dynamic differential games to capture the temporal evolution and adjustment of strategies, examining dynamic game strategies under different compensation scenarios (non-horizontal ecological compensation, horizontal ecological compensation and fully shared ecological compensation). A new interest distribution model is proposed, with empirical analysis conducted using Shanghai as a case study to validate the reliability and feasibility of the model. The findings indicate: (1) Government intervention combined with horizontal ecological compensation significantly improves waste management efficiency and urban welfare. The compensation mechanism fosters regional cooperation, optimizes resource allocation, reduces decision-making conflicts and enhances overall processing effectiveness. (2) Without a compensation mechanism, high costs in export regions and low benefits in import regions result in low cooperation willingness. The ecological compensation mechanism enhances willingness to cooperate by fairly distributing costs and benefits, optimizing long-term cooperation and overall gains. (3) Complete shared ecological compensation is optimal, though partial shared mechanisms are also effective in practice. Proper interest and ecological compensation ratios can significantly improve waste management efficiency and urban environment, strengthening long-term cooperation. The study theoretically expands the dynamic optimization and cooperation mechanism analysis in waste management, provides solutions for environmental policy formulation in cross-regional waste handling and offers new perspectives and tools for addressing complex issues in cross-regional environmental governance, including targeted policy recommendations with practical significance for enhancing cross-regional waste management.

Piled smouldering has great potential for treatment and utilization of biomass wastes. However, its unsteady-state nature limits its industrial utilization, as well as treatment of smoke. This article addresses this issue by proposing the sequential operation of numerous smouldering chambers to realize steady- or quasi-steady-state piled smouldering. The superposition characteristics of sequential unsteady-state curves were analysed theoretically, and a code was developed to determine an appropriate number of piled chambers at an allowance oscillation percentage. Smouldering experiments were performed on a single mini chamber (length × width × height: 340 × 140 × 140 mm³) containing piled wood pellets mixed with wood powder. The superposition of sequential burning rate curves was demonstrated using the code based on the mass loss data of experiments. Analysis shows that the perfect-steady state is possible given the superposition value of the burning rate curve is a constant in this proposed system. Experiments show that the molar ratio of CO/CO₂ in smoke is almost a constant around 0.5 during densely piled smouldering, showing the great potential for self-sustained burning out the smoke. Based on the experimental results, the calculation results show that the relative oscillation range of burning rate (OSC) decreases from 75% to 3% while increasing the number of chambers from 2 to 7. This work provides a novel technology to enable quasi-steady-state smouldering for industrial utilization.

The introduction of appropriate solid waste management (SWM) strategies can foster the mitigation of waste open dumping and burning in low-income developing cities. In this work, the SWM system in Gulu (Uganda) has been studied, and a material flow analysis, also of informal flows of waste, has been carried out. Moreover, the effectiveness of the SWM system of St. Mary's Lacor Hospital in Gulu was evaluated. Waste has been characterized and a material flow analysis allowed to highlight the difference with the current situation in the remaining part of Gulu. The sustainable practices already implemented in the hospital compound were studied to be replicated in Gulu to mitigate SWM impact in terms of global warming potential. Inadequate financial resources pose a hurdle for Gulu municipality in managing municipal solid waste (MSW) effectively. The SWM system of the hospital demonstrated both financial and managerial competence, paving the way to promote waste recycling actions acting as a hub for fostering sustainable and health-conscious valourization technologies, while discouraging waste open burning and dumping. This study estimated that the total CO₂-eq emissions from open dumping and open burning avoided in 2030-2050, if Gulu would appropriately dispose of MSW by 2030, are equal to about 17,000 metric tonnes per year (t year^-1). This work suggests appropriate strategies to mitigate waste open burning in low-middle income countries. The results can be helpful for waste management planners and practitioners providing important information for the use of appropriate technologies in low-middle income developing cities.

Phosphorus (P) is a vital nutrient for plant growth and food production. Excessive amounts of P fertilizers to a greater extent of crop P offtake are inevitably applied due to low utilization efficiency, causing environmental pollution. This study aimed to evaluate biochar-based fertilizers (BBFs) produced by co-pyrolyzing algae (A) and hazelnut shell (H) biomasses with triple superphosphate (TSP) at a ratio of 4:1 (w/w). The potential of the slow-release performance of BBFs was studied during kinetics experiments. The co-pyrolysis of biomasses with TSP yielded BBFs with significantly different properties, including electrical conductivity, pH, elemental ratios, functional groups, specific surface area and pore size characteristics. Phosphorus release from all biochars and BBFs followed the Elovich model, except for TSP and H+TSP. Kinetic studies revealed prolonged P-release times and slower release rates for BBFs compared to conventional TSP. So that, TSP released 100% of the total P, whereas H+TSP and A+TSP biochars released only 3.14% and 5.14% of the total P, respectively, during a 240-hour experiment. The slow-release performance of BBFs suggests their potential as promising alternatives to conventional phosphate fertilizers. BBFs have the potential to enhance P utilization efficiency, increase crop yield and mitigate the environmental impact of P fertilizer runoff.

In many developing countries, inefficient waste source separation poses a significant challenge to sustainable waste management systems, hindering progress towards a circular economy. Previous research has shown mixed results regarding the effectiveness of informational interventions and has not thoroughly evaluated regulatory measures. This study innovatively employs a quasi-experimental design, enhanced by successive surveys, to assess the impact of targeted interventions on behavioural changes in waste separation practices. Utilizing the Health Action Process Approach, we introduced three interventions - posters, educational lectures and a supervision policy - over 8 weeks among university students. Our results indicate stepwise improvements in waste separation accuracy: posters modestly increased awareness without significantly altering behaviours; educational lectures led to a 40% increase in the food waste separation rate and supervision achieved over 90% separation purity, but with an increase in 'fly-dumping'. The interventions incurred costs of 36, 60 and 365 RMB per capita annually. This research underlines the importance of customized informational interventions and the costs and challenges of initial regulatory measures in waste management, offering crucial empirical evidence and insights for creating impactful environmental behaviour change interventions.

This article examines a specific subtype of informal waste picking: deposit picking. Despite its global prevalence, waste picking has neither been extensively studied in the Nordic countries nor in the context of a deposit-refund system. Through interviews and text analyses of waste pickers in Stockholm, Sweden, similarities and differences between deposit picking and traditional waste picking are uncovered. For example, unlike other waste materials, the income from deposits is stable. The focus on beverage containers and the ability of reverse vending machines to sort the containers, lowers the knowledge threshold to begin the activity. The lightweight nature of beverage containers makes collection mobile, and deposit pickers often carry only a bag. The deposit pickers are mainly older, poor and male. Similar to traditional waste pickers, deposit pickers are central to the formal waste system, but their work is invisible, and foreign deposit pickers, in particular, are stigmatized. The dual invisibility of their labour and contributions, coupled with their independence from formal social systems, highlights the need for internal organization and representation within the formal systems.

Discrimination of waste plastics according to brominated flame retardant (BFR) concentration is essential to ensure quality and safety in recycling. We present a sensor fusion approach to classify BFR-containing plastic waste by combining Raman and near-infrared (NIR) spectroscopies. We analysed 210 waste plastic samples sourced from waste electronics and electrical equipment stream and 25 laboratory-made plastics. The Raman spectra were acquired in the range 27-2481 cm^-1 using a time-gated Raman and the NIR spectra in the range 4000-5260 cm^-1 using a novel active hyperspectral sensor. Total elemental bromine concentrations were determined with X-ray fluorescence spectroscopy and used as reference for training extremely randomized trees classifiers for high- and low-bromine plastics with different thresholds of segmentation. The classifier models were built using Raman and NIR spectral data after reducing dimensions with principal component analysis, both separately and by fusing the data. We achieved over 80% balanced classification accuracies using all models, with significant improvements by data fusion.

This study investigates, for the first time, the anaerobic digestion of food waste in Kuwait to optimize methane production through a combination of artificial neural network (ANN) modelling and continuous reactor experiments. The ANN model, utilizing eight hidden neurons and a 70-20-10 split for training, validation and testing sets, yielded mean squared error values of 0.0056, 0.0048 and 0.0059 and coefficient of determination (R²) values of 0.9942, 0.9986 and 0.9892, respectively. Methane percentages in biogas were predicted using six parameters: biomass type, pH, organic loading rate (OLR), hydraulic retention time (HRT), temperature and reactor volume. To validate the ANN results, continuous reactor experiments were conducted under an OLR of 3 kg VS m⁻³ d⁻¹ and HRT of 20 days at varying temperatures (35°C, 40°C, 45°C, 50°C and 55°C). The experiments demonstrated optimal methane production in the mesophilic range, with ANN predictions closely aligning with experimental data up to 45°C. However, deviations were observed at higher temperatures, particularly under thermophilic conditions beyond 50°C. This study provides novel insights into waste-to-energy initiatives in Kuwait and highlights the potential of integrating computational models with empirical data to enhance biogas production processes.

Zimbabwe's tourism industry, renowned for its natural wonders and cultural heritage, faces a looming energy crisis rooted in the detrimental over-reliance on fossil fuels and the underutilization of substantial waste resources that lie dormant. The article investigates multifaceted relationship between six independent variables: landfill gas recovery and anaerobic digestion, pyrolysis and gasification, incineration, biogas production, biodiesel production, ethanol production and syngas fermentation and one dependent variable: energy development and sustainability. In this study, a quantitative methodology was adopted, involving the gathering of data from 519 stakeholders in the tourism supply chain through a simple random sampling technique, with the sample size determined using the Krejcie and Morgan table. The distribution of questionnaires was facilitated through Google Forms, and the data analysis was conducted using Smart PLS. Statistical findings indicate direct significant relationship between variables, and t-statistic values all hypotheses were all greater than the threshold of 1.96, ranging from a minimum of 2.911 to a maximum of 9.431. These findings underscore the robustness of the relationships between the waste-to-energy technologies and energy development and sustainability within Zimbabwe's tourism sector. This empirical evidence highlights the substantial potential for these innovative technologies to play a pivotal role in mitigating the energy crisis and fostering sustainable energy development.

Enhancing the sequestration capacity of waste concrete is crucial for achieving carbon neutrality within the construction industry. Although existing studies primarily focus on theoretical analysis of concrete carbon sequestration, limited attention has been paid to explore the potential of waste concrete sequestration during stockpiling phase under varying environmental conditions. To fill this knowledge gap, we developed a CO₂ uptake calculation model tailored for the stockpiling phase of waste concrete. This model investigates the impact of crush size, stacking method and environmental conditions on the total carbon sequestration capacity and efficiency, identifying the most advantageous approach. Our findings reveal the following: (1) Increasing the crush size of waste concrete enhances its carbon sequestration capacity, albeit extends the sequestration duration. A crush size of 5-20 mm is deemed optimal for achieving the desired sequestration efficiency. (2) The optimal stacking method involves smaller piles with reduced radii and angles. (3) High temperatures and humidity levels accelerate the sequestration rate. Practical measures such as watering and covering can be employed to enhance carbon sequestration. (4) In 2021, China's waste concrete exhibited a declining sequestration potential from the southeast to the northwest and northeast regions. The maximum sequestration potential has the capacity to neutralize up to 4% of the carbon emissions generated by the construction industry in that year. This research provides a foundation for accurate assessment and the development of effective carbon sequestration strategies for waste concrete.