Journal of Material Cycles and Waste Management最新文献

Municipal solid waste incineration (MSWI) fly ash is classified as hazardous waste because of its toxic constituents and requires solidification/stabilization (S/S) prior to safe landfill disposal. Selenium (Se), a particularly harmful element, presents significant environmental risks; however, research on its effective treatment remains limited, and no widely accepted remediation technology is currently available. This study evaluated the effectiveness of various S/S agents in stabilizing Se in fly ash, with a particular focus on iron micro-powder (IMP). The results indicate that IMP demonstrates superior solidification efficiency compared to conventional heavy metal chelating agents such as sodium sulfide and sodium dimethyldithiocarbamate, which exhibit negligible effectiveness. Under acidic conditions, the IMP achieved a Se stabilization rate of up to 97.6%, whereas its efficacy decreased in alkaline environments. To clarify the stabilization mechanism, the interactions between IMP and Se were examined in simulated leachates at different pH levels. SEM, EDS, and XPS analyses revealed that the primary S/S mechanism of IMP involves adsorption and reduction reactions. Specifically, the tetravalent selenium ions in solution were reduced to zero-valent selenium, which was subsequently deposited onto IMP surface, thereby achieving stabilization. Furthermore, the reaction process is significantly influenced by the environmental pH.

Collecting samples of waste generation is essential for designing effective waste management strategies. Conducting waste generation sampling over a week or an 8-day period needs substantial demands on resources. The resource-intensive nature of extended sampling periods is notable. Shortening sampling days is beneficial and perhaps can also be cost effective. Cost-effective means reducing resource demands while maintaining the accuracy and reliability of waste generation data. The solid waste generation sampling data from two sub-districts both in Banyuwangi Regency and in Jembrana Regency, Indonesia were used for data source. Normality test and ANOVA (analysis of variance), followed by Tukey's post hoc analysis was utilized to analyze the variability among sampling duration, weekdays and weekend, and seasonal change. The generation of household wastes appears consistent in patterns over 4 or 8 days, irrespective of the sampling days falling on weekdays or weekends. When comparing the rainy and dry seasons, it was observed that only one sub-district in Muncar exhibited a statistically significant difference in waste generation. The remaining locations demonstrate no substantial statistical variation between the two seasons. This suggests a level of uniformity in waste generation across different time periods and seasonal condition, with Muncar being the sole exception.

The recycling and reuse of copper and aluminum from end-of-life vehicles (ELVs) present both significant economic and environmental opportunities. However, substantial differences in the amounts of copper and aluminum used in vehicles have led to an imbalance in the quantity of small scrap samples. Effectively detecting and sorting non-ferrous scraps from ELVs remains an urgent challenge. To address these challenges, this paper proposes an improved YOLOv8 detection algorithm, integrated with a small sample enhancement method for non-ferrous scrap. Sorting software was developed for conducting the experiments. The results demonstrate that efficient image fusion can be achieved by generating targeted images for underrepresented classes and carefully designing the fusion position, size, and method. The improved YOLOv8 detection model trained on the augmented dataset achieved optimal performance, with recognition accuracies of 98.5% for aluminum scrap and 98.1% for copper scrap, and a detection speed of 50 FPS, meeting real-time detection requirements. Furthermore, the developed system and software yielded sorting accuracy of 93.3% and purity of 92.6% during the scraps sorting experiments, both exceeding the industry standard of 90%. The proposed method of recovering these metals through sorting and recycling is not only environmentally friendly and energy-efficient but also offers substantial economic advantages.

The rapid growth of construction waste combined with limited land availability, strict regulations for waste disposal, and associated health and environmental risks, has prompted the construction sector to focus on reducing waste generated due to construction activities. Zero waste is a concept closely aligned with the circular economy (CE), which aims to eliminate the generation of waste. However, achieving zero waste requires additional techniques and efforts beyond current on-site waste management practices. The lack of methods to assess a site’s progress towards zero waste by incorporating CE principles has motivated this research. The objective of this paper is to present the development of an assessment tool that can be used to assess the progress of a construction site towards zero waste. The research used a mixed methods approach combining a comprehensive literature review, semi-structured interviews, and case studies, to develop and validate the tool. The validation through case studies revealed that embedding CE principles of reduce, reuse, repurpose, recycle, and recover helps site managers take active steps towards achieving a zero-waste target. The developed tool aids construction site managers in making material-level disposal decisions and implementing managerial-level initiatives to drive zero-waste target.

An effective organic waste management can be achieved using black soldier fly (BSF) larvae, converting waste into a valuable biomass high in protein and fat content. This systematic review examined BSF bioconversion for processing industrial organic by-products, focusing on how substrate composition and type influence larvae protein and fat content. The objectives were to evaluate the potential of industrial organic by-products as BSF rearing substrates. A shortlisted number of peer-reviewed articles has been comprehensively analyzed. The results indicate that BSF bioconversion can be used to manage a variety of industrial organic by-products. The industry types in this article are divided into two categories: (1) Food Products, Beverages, and Tobacco Products; and (2) Production, Processing, and Preservation of the Meat, Fish, Fruits, Vegetables, Oils, and Fats. The nutritional composition of BSFL reared on these substrates, including total fat, protein, fatty acid and amino acid levels, was explored. The characteristics of larvae and prepupae were discussed for their potential uses. The bioconversion products can be used as animal feed, raw material in biodiesel production, cosmetics, pharmaceuticals, and biopolymers production. This article assessed the environmental impact of BSF bioconversion, encompassing greenhouse gas emissions, to determine its viability relative to other waste management methods.

Phosphogypsum (PG) is a typical by-product of producing phosphoric acid using wet process sulfuric acid, and contains organic matter, heavy metals, and fluoride as its primary impurities. However, it is rich in plant-available elements such as P and K, making it an ideal soil amendment. In the process of agricultural production, agricultural organic solid waste also poses a threat to the environment, while affecting the process of building a beautiful countryside. Traditional agricultural organic solid waste treatment methods, including landfill disposal and incineration, are resource wasteful and polluting. Landfilling could trigger geological collapse, while incineration caused atmospheric pollution and forest fires. The co-utilization of PG and organic solid waste co-pyrolyzing the mixture to produce organic nutrient-rich soil was explored by mixing corn straw and PG. This study investigated the leaching toxicity and available element content of the pyrolysis products at different temperatures, ratios, and times. The experimental results found that co-pyrolysis achieved the solidification and stabilization of harmful elements, the maximum release of plant usable forms elements under conditions of biomass addition of 20%, pyrolysis at 900℃ for 1 h. This study provides a new direction for solid waste co-resource treatment, which can effectively alleviate the environmental pollution issues associated with inorganic and organic solid waste.

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Amman, Jordan, faces escalating challenges in municipal solid waste management due to rapid urbanisation, population growth, and limited recycling participation. This study develops a novel decision-support framework that combines a System Dynamics (SD) model with fuzzy Analytic Hierarchy Process (AHP) and Artificial Neural Network (ANN) validation. The model explicitly integrates population trends, social awareness, recycling initiatives, and informal waste picker contributions into municipal waste forecasting. Social awareness was quantified using a fuzzy AHP survey of households, and its influence on source sorting behaviours was embedded as a dynamic feedback variable. Model validation demonstrates that the SD model achieved 94.3% prediction accuracy, outperforming the ANN’s 91.5%. Scenario testing showed that increasing household participation in source sorting by 20% annually reduced the growth rate of waste generation from 2.56% to 1.38%, diverting more than 60,000 tonnes from landfill by 2030. These findings underscore the critical role of behavioural interventions, beyond technical solutions, in reducing landfill dependency. By embedding social and behavioural variables within a predictive modelling framework, this study contributes a replicable tool for policymakers in Amman and other rapidly urbanising cities to advance circular economy strategies and long-term landfill planning.

Electronic waste (e-waste) poses environmental and health challenges, necessitating effective inventory management systems. This systematic literature review (SLR) explores the landscape of e-waste inventory and management using distributed systems, focusing on cloud, Internet of things (IoT), and blockchain. A total of 21 relevant research papers were selected and analyzed, considering factors, such as efficiency, scalability, security, transparency and traceability, advantages, limitations, and future work. The findings reveal that distributed systems, including cloud, IoT, and blockchain, offer promising solutions for optimizing e-waste management. These technologies enable enhanced operational efficiency, real-time monitoring, and data-driven decision-making. The SLR also identifies several future research opportunities. Transparency and traceability can be enhanced to track e-waste throughout the management process. Advanced data analytics techniques can extract insights from e-waste data, enabling informed decision-making and resource allocation strategies. While various studies touch upon specific components or subsystems, a holistic approach is needed to effectively manage e-waste on a scale. This includes addressing the gaps in scalability and integration of cloud computing and IoT technologies. Furthermore, the research should focus on ensuring transparency, traceability, and data security while also optimizing energy consumption for sustainable e-waste management. The identified challenges and future research opportunities serve as a roadmap for researchers to advance the field and optimize e-waste management processes toward a sustainable future.

The recovery of graphite has been investigated mainly for black mass from spent Li-ion batteries. However, less research has been performed on the graphite recovery from spent Zn/C and alkaline batteries. Graphite is a critical raw material and it is necessary to search for new secondary sources to recover it. The main advance of this research is to study the application of froth flotation for the recovery of graphite from black mass of spent Zn/C and alkaline batteries. The effect of two thermal pre-treatment processes (roasting at 340ºC and pyrolysis at 600ºC) plus an attrition stage previous froth flotation have been analyzed. Experimental results showed that pyrolysis treatment of black mass from Zn/C and alkaline batteries allows greater selectivity of graphite versus Mn/Zn minerals. This may be due to a modification of the particle size do related to the removal of the finest ones, as well as a modification of the surface chemistry of the graphite and/or manganese oxides. In addition, the thermal treatment also modifies the mineralogical composition of the Mn oxides.

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