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In the present investigation, a thorough examination of waste composition was undertaken in the Tamale Metropolis, Ghana. The methodology employed was carefully designed, incorporating both commercial and residential sectors as well as various socioeconomic classes. Source-based sampling of waste materials covered a range of locations, including households, markets, hotels, and restaurants, while socioeconomic-based categorization followed the zoning of the metropolis. Waste audit sampling involved collecting a total of 90 batches of solid waste over the three-month period from August to October 2023. The primary objectives were to physically characterize the waste and evaluate its chemical properties through proximate and ultimate analysis of waste fractions, aiming to determine the waste-to-energy potential and compatibility with waste-to-energy technologies. The study revealed that the Tamale Metropolis generates 176.1 tons/day of Municipal Solid Waste (MSW) at a rate of 0.47 kg/capita/day.Organic matter constituted the majority (44.9%), followed by inert, miscellaneous, and plastic waste at 20% each. The remaining 14.3% comprised paper, metal, glass, leather, and textile components. Notably, the hospitality sector exhibited the highest organic matter content at 62.3%, contrasting with average households and markets at 44.9% and 13.1%, respectively. Moisture content ranged from 5.4% to 12.6%, volatile solids from 21.8% to 77.2%, and gross calorific values from 7.9 MJ/kg to 28.9 MJ/kg. Household waste demonstrated the highest energy content at 6693.8 kcal/kg, followed by hotels/restaurants (2003.94 kcal/kg) and markets (1883.62 kcal/kg). This study's findings offer valuable insights that can inform the development of effective policies by regulatory bodies such as the Public Utility Regulatory Commission (PURC) and the Ghana Ministry of Energy, as well as city authorities like the Tamale Metropolitan Assembly and the Environmental Protection Agency. These insights can be used to address waste and energy challenges in the metropolis. Implications : The findings reveal critical insights with substantial implications for stakeholders and regulatory bodies. It emphasizes the waste-to-energy potential of various waste fractions, highlighting the need for sustainable municipal waste management strategies. Particularly, the high organic content in the hospitality sector presents significant energy recovery opportunities. For bodies like the Public Utility Regulatory Commission and the Ghana Ministry of Energy, this data is crucial for developing policies that support waste-to-energy technologies. Additionally, the Tamale Metropolitan Assembly and the Environmental Protection Agency can use these insights to improve local waste management practices, customizing interventions to address specific sectoral waste composition. The study also underlines the importance of ongoing monitoring to ensure the effectiveness of these strategies over time.

The advancement of co-processing solid wastes in coal-fired boilers is significant for waste recycling and contributes to the sustainable development of the coal-fired power industry. However, concerns over the emission of dioxins during co-processing have prompted a comprehensive investigation into the dioxin emission properties. In this study, the PCDD/F emission concentrations of seven coal-fired boilers, including three pulverized coal boilers and four circulating fluidized bed boilers were examined. The results indicate that co-processing solid wastes in coal-fired boilers did not lead to an increase in the mass concentration of dioxins in either the flue gas or solid samples, and the international toxic equivalents (I-TEQ) of dioxins in the flue gas complied with prevailing emission standards (0.1 ng I-TEQ/Nm 3 ) in China, proving that coal-fired boilers co-processing would not raise the emission risk of dioxins. The types of waste during co-processing had minimal effect on the I-TEQ of dioxins. A significant proportion of PCDD/Fs was observed in the ash samples, while only 13.0-25.7% and 0.7-6.8% of dioxins were distributed in the boiler slag and the flue gas, respectively. The emission factor of dioxins under the blank conditions ranged from 0.009 to 0.327 ng I-TEQ/kg-coal, while it ranged from 0.015 to 0.129 ng I-TEQ/kg-(coal+waste) under the co-processing conditions. The reduction of emission factor under co-processing condition could be attributed to the significant decrease of dioxins I-TEQ., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The EU's circular economy concept necessitates increasing the recycling ratio of municipal solid wastes. There are many existing mechanical-biological processing plants in Hungary for the preparation of residual municipal solid wastes (RMSWs). The two most important products of these plants are the bio-fraction and the refuse derived fuel (RDF). Currently, there are problems with both of these material streams in Hungary, since most of the bio-fraction is still landfilled, and the local thermal utilisation of the RDF has not been implemented yet. The high moisture content of the produced bio-fraction and RDF causes difficulties for the downstream operations; therefore, there is recent engineering interest in drying and agglomeration of these materials. The authors have carried out systematic and parallel drying and briquetting experimental series to study the effect of the material, material composition, mass (volume or surface) of the material, particle size distribution and pre-treatment with a cutting mill on drying intensity in a 1 m 3 oven and their effect on briquettability by a laboratory briquette press. The initial slope of the relative moisture loss as function of time was determined. Process engineering design methods of convective hot air-drying can be further developed taking into account the research results. Results can be used for the design of the feed of a pyrolysis reactor once reactor experiments have provided the optimal feed requirements., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Refuse sorting is an important cornerstone of the recycling industry, but ever-changing refuse compositions and the desire to increase recycling rates still pose many unsolved challenges. The digitalisation of refuse sorting plants promises to overcome these challenges by optimising and automatically adapting the sorting process. This publication describes a system for image capturing, segmentation-based refuse recognition and data analysis of shredded refuse streams. The image capturing collects multispectral 2D and 3D images of the refuse streams on conveyor belts. The image recognition performs a semantic segmentation of the images to determine the refuse composition from the 2D images, whereas the 3D images approximate the volumes on the conveyor belts. The semantic segmentation is done by a combined convolutional neural network model, consisting of a foreground-background and a refuse class segmentation. Both models rely on synthetic training data to reduce the necessary amount of manually labelled training data, whereas the final segmentation performance reaches an Intersection over Union of up to 75%. The results of the semantic segmentation and volume estimation are combined with data of the shredding machinery by transforming it into a unified representation. This combined dataset is the basis for estimating the processed refuse masses from the semantic segmentation and volume estimation., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

One of the most pressing environmental issues is how to properly dispose of municipal solid waste (MSW), which represents both a substantial source of concern and a challenge. The current study evaluated cobalt (Co) accumulation in MSW, their uptake by different vegetables grown for two years, and related human health risks. Vegetables were grown in four different groups, such as one control (ground soil), and the remaining treatment groups (T1, T2, and T3) received varying concentrations of MSW. The analysis of Co was done through an atomic absorption spectrophotometer (AAS). Results revealed that the concentration of Co was higher in all the vegetables (n = 15) grown in soil supplemented with 75% MSW during 2nd growing year. Among all vegetables, the highest concentration of Co was observed in Solanum tuberosum at T3 during 2nd growing year. The pollution load index (PLI) value for vegetables during both growing years was more than 1 except in control soil. The findings indicated that the highest enrichment factor (EF) and hazard resilience index (HRI) value of 0.09 was present in S. tuberosum. Health index values for cobalt in the study were below 1. The HRI < 1 indicated that consumers do not face any immediate health risks. The investigation of Co concentrations in blood samples obtained from individuals residing in different areas contributes a human health perspective to the research. The findings indicate that the concentration of Co rises with an increasing proportion of MSW. While the metal levels in MSW-treated soil were not high enough to classify the soil as polluted, the results recommend that recycling MSW can substitute mineral fertilizers. Nevertheless, the presence of cobalt in MSW may directly affect soil fertility and could impact crop production and human health., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The recycling of bio-waste from households is an essential factor in achieving the recycling quotas for municipal waste laid down by the EU. A major problem is posed by impurities in the bio-waste collected, such as plastics, metals and glass. It is virtually impossible for compost producers to produce quality-assured compost from bio-waste with an impurity content of more than 3 wt% OS . The draft of the new Austrian Compost Ordinance stipulates a limit of 2 wt% OS of interfering substances in accepted bio-waste. A rapid measurement method has been developed and comprehensively validated for the immediate on-site checking of contaminant content at the bio-waste bin or in a vehicles. Data on the type and amount of impurities collected in the course of sorting analyses carried out over several years in 10 selected areas in Styria, Austria showed an average impurity content of 2.1 wt% OS . This impurity content can be considered representative for rural and urban communities in Austria. Among the interfering substances, plastics predominate, at 53%, of which pre-collection bags made of plastics form the highest proportion. A more detailed examination of pre-collection bags shows a higher proportion of use of biodegradable plastic bags, which have become more numerous in recent years in the more rural communities. In order to reduce mis-sorting, the effect of a wide variety of measures on citizens was tested in selected areas. Here, the distribution of paper bags as well as the threat of a cost increase due to special collections in combination with distribution of these bags were the methods with the greatest effect. Motivational letters and the threat of special collections, however, showed no significant result., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article.

The treatment of food waste by anaerobic digestion (AD) still faces several challenges. Fractionating the waste, with a screw press separator, into a liquid phase rich in soluble compounds and a solid fraction could contribute to reduce these challenges, provided that the solid fraction is valorized. To do so, hydrothermal carbonization was shown to be a promising option. Indeed, HTC produced a hydrochar having an energy content 8-38 % higher than the initial feedstock and a process water that could be further converted to methane through anaerobic digestion, with a yield of 160-230 mL CH 4 per g of COD. The methane production was shown to be influenced by the recalcitrance of certain HTC products, with hardly no inhibition detected. The integrated 3-step process produces as much energy as conventional anaerobic digestion, while reducing challenges associated to low loading rate and digestate handling., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Her Majesty the Queen in Right of Canada, as represented by National Research Council Canada. Published by Elsevier Ltd.. All rights reserved.)

Sustainable waste management (SWM) practices are crucial for tackling environmental concerns under a circular economy (CE) scope. Thirty-one OECD countries have been evaluated on their national SWM performance via Malmquist data envelopment analysis (DEA) methodology from 2000 to 2021. The Malmquist (MPI) and Malmquist-Luenberger (MLPI) productivity indices are compared based on their total factor productivity (TFP) and its elements (i.e., efficiency and technological changes). Both models have the gross domestic product (GDP) as a desirable output, but MLPI also incorporates municipal solid waste (MSW) generation and greenhouse gases (GHGs, i.e. CO 2 and CH 4 ) as undesirable outputs. MLPI has a lower average performance (1.74%) than MPI (4.42%), meaning that the incorporation of waste and GHGs has diminished an OECD country's SWM performance by 2.5 times on average. In essence, it is innovation that drives TFP in the selected countries. Overall, the synergistic implementation of SWM practices, Malmquist DEA-based methodology, and CE principles is crucial for advancing sustainable development and achieving a circular and resilient future. The manuscript also offers policy implications regarding the need of financial incentives, vocational training, and fostering stakeholder encouragement in the waste sectors to implement CE solutions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

To foster a circular economy, the EU will increase recycling targets for packaging materials, including aluminum, ferrous metals and glass. Recovery of packaging metals from incineration bottom ashes (IBA) from municipal solid waste incineration can contribute to achieving these targets. Nevertheless, recoverable metal and glass amounts from IBA, and in particular IBA from fluidized bed combustion, are rarely investigated. Therefore, this work aims to assess the recoverable amounts of aluminum, magnetic ferrous metals and glass > 4 mm from different types of IBA through enhanced treatment. In an industrial-scale treatment experiment with one batch of IBA from grate and one from fluidized bed combustion, masses and compositions of all output flows of the treatment plant were determined. Material flow analysis was used to study the distribution of the investigated materials during the treatment process. Results show that glass separation was not feasible for the grate IBA, which only contained 7 % glass > 4 mm. The fluidized bed IBA contained 42 % glass > 4 mm, of which 72 % were recovered. More aluminum and magnetic ferrous metals > 4 mm were found in the fluidized bed IBA, also exhibiting less mineral agglomeration compared to those from grate IBA. The study demonstrated that enhanced industrial IBA treatment can recover > 95 % of aluminum and magnetic ferrous metals > 4 mm, not observing significant differences between these metals. Thus, a cutting-edge IBA treatment can enable the recovery of recyclable material from IBA and therefore contribute to a circular economy. Furthermore, fluidized bed IBA shows advantages regarding its recycling options compared to grate IBA., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

The escalating global issue of soil pollution by heavy metals, particularly incinerated municipal solid waste fly ash (IMSWFA), necessitates effective remediation strategies. The prevailing approach for safely disposing and utilization of IMSWFA involves high-temperature sintering. In this work, we propose a cost-effective method to produce ceramsites by utilizing IMSWFA, municipal sludge (MS), contaminated soil (CS), and iron tail slag (ITS). After conducting a comprehensive analysis and comparison of outcomes obtained from orthogonal experiments and single-factor experiments, it was determined that the optimal preparation conditions for achieving desirable results are preheating at a temperature of 400 °C for 15 min followed by sintering at a temperature of 1150 °C for 10 min. The optimal ratio of raw materials for ceramsites is 15 % IMSWFA, 15 % MS, 58 % CS, and 12 % ITS. The ceramsites, prepared in accordance with the specified process and raw material ratio, exhibit remarkable properties including robust stability, minimal water absorption, reduced weight, and elevated cylindrical compressive strength. The ceramsites demonstrate an exceptionally high heavy metal loss ratio ranging from 91 % to 100 %, while exhibiting significantly lower leaching quantities of these metals compared to the raw materials. Additionally, aging tests of ceramsites were performed under UV light and acid/alkaline etching to simulate the real-world environment. This work can be utilized to investigate the long-term environmental impact of ceramsites derived from municipal solid waste (MSW), thereby making a valuable contribution to the advancement of solid waste management technology., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Municipal solid waste management is one of the greatest challenges for environmental sustainability and well-being in developing countries, where the infrastructure and financial resources required to carry out such services are often lacking. The design of solutions that adequately respond to local needs must be based on quality information about the quantity and composition of the generated waste and current management practices. This study evaluated domestic waste generation and its management in 81 communities in Ecuador based on sampling at the source and population surveys. An average household waste generation value of 0.613 kg/cap/d was obtained, of which biowaste accounted for 68 % of the total generation, followed by 23 % recyclable material and 9 % other non recyclable waste. Even though some councils have set up differentiated collection systems for inorganic material in urban areas, these systems are still absent in many rural areas, which explains why waste is not separated in 70 % of the studied communities. Furthermore, only 70 % of the rural population in the country has a waste collection service, and waste in some communities is still thrown into water bodies or burned. Rural populations often use biowaste at home by composting it or as animal feed, which are good practices that should be considered in the diagnosis reports and incorporated into waste management planning., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The increasing interest in Waste-to-Chemical (WtC) technologies operating with Solid Recovered Fuels (SRF) from non-recyclable plastic streams requires a quantitative analysis on the actual convenience of this alternative valorization pathway. This study assesses SRF in selected WtC technologies for hydrogen and methanol production and compares it with the well-established practice of co-combustion in the cement industry. Two case studies are considered: the first one represents the current scenario where SRF is used in co-combustion for cement production meanwhile the chemical is produced by steam reforming; in the second scenario, the cement plant is fed with pet-coke only, leaving SRF as a feedstock for WtC. WtC performance assessment has been carried out in Aspen Plus®, whereas cement production and steam reforming have been characterized based on literature information. The two scenarios have been assessed for two SRF qualities (different LHV and biogenic content) calculating primary energy and fossil CO 2 emissions. The results show that SRF from plastic waste as a feedstock in WtC is less effective than its utilization in cement plant: when WtC technology for hydrogen production is adopted, additional 9.1% (SRF-1) and 8.6% (SRF-2) of energy consumption is estimated and 25.8% (SRF-1) and 24.1% (SRF-2) additional fossil CO 2 is emitted with respect to the corresponding conventional cases (i.e., chemical from steam reforming and SRF burnt in the cement kiln). When considering methanol production, WtC technology requires 6.2% (SRF-1) and 5.6% (SRF-2) increase of primary energy and 30.2% (SRF-1) and 28.4% (SRF-2) additional fossil CO 2 against the conventional cases., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The identification of waste composition based on target-detection is crucial in promoting sustainable solid waste management. However, discrimination of different solid waste categories in the presence of incomplete and insufficient feature information remains a challenge in multi-target detection. This paper proposes an improved You Only Look Once (YOLOX-S) model that enables the effective recognition of different waste components in complex environments, which enhances feature-information extraction ability regarding different dimensions by introducing a convolutional block attention module, an adaptive spatial feature fusion module, and an improved efficient intersection-over-union loss function. The improved model was trained on a self-constructed image dataset with multiple waste components and targets in various complex scenarios, including interference from similar color backgrounds, similar waste localization, and mutual waste occlusion. The experimental results showed that the improved model achieved a mean average precision (mAP) of 85.02 %, an increase of 5.32 % over the original YOLO model's mAP, and that it reduced incidents related to inaccurate positioning and false and missed detection. Moreover, the improved model outperformed classical detection models including support vector machine, RestNet-18, and RestNet-50 on a public dataset, achieving a mAP of 94.85 %. The improved model is expected to be applied to intelligent monitoring for waste components in scenarios including indiscriminate waste disposal and illegal dumping, providing decision support for emergency management., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The miniaturized gasification-combustion model has potential advantages in treatment of rural solid waste (RSW) in China. In this study, the gasification-combustion technology concerning air-staged technology was employed in the treatment of seven combustible components in RSW, focusing on the analysis of heavy metal migration characteristics. Firstly, a comparison was made between combustion and gasification-combustion regarding the migration characteristics of heavy metals, demonstrating that gasification-combustion effectively reduces the volatilization rate of heavy metals. The largest reduction in volatility was 12.99 % for Cu. Secondly, this study explored reaction temperatures and oxygen concentration in the gasification zone, concluding that under experimental conditions mentioned herein, optimal gasification temperatures for curing heavy metals were determined to be 700 °C while maintaining an optimal ratio of air (RA) at 0.5 during gasification. Finally, the interaction of inorganic elements with different components on heavy metal migration was revealed by co-gasification-combustion of equal mass mixture of two components. The P, S, Cl contents and the inorganic mineralogical composition of the RSW are the key factors influencing the transport properties of heavy metals. The two-component synergistic effect of RSW studied in this paper has guiding significance for limiting the proportion of RSW components to control heavy metal emission in gasification-combustion process., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study examined the role of waste management authorities in promoting public awareness of municipal solid waste management (MSWM) through the lens of the expansion diffusion theory (EDT). EDT emphasizes the spread of new ideas and practices within a society through various communication channels and distinct individuals within each system. We employed a mixed-method approach using 116 survey responses from Lagos residents and five semi-structured in-depth interviews. Our findings reveal the need for a more structured approach to create public awareness of MSWM, considering the distinct groups of residents in Lagos and their responses to innovation and knowledge diffusion. We propose four pillars on which waste management authorities in developing countries can sustain their MSWM awareness campaigns, as well as an awareness campaign strategy flowchart. Our findings add to the expanding body of research on public awareness and participation in MSWM, emphasizing the critical role that waste management authorities can play in fostering sustainable waste management awareness and practices., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Evaluating model parameters through laboratory experiments presents challenges due to waste heterogeneity and scale effects. This study investigates the settlement response of selected models using field-scale data collected from the filling and post-closure phases of the Ste. Sophie landfill in Canada. The first model was based on primary and secondary compression ratios, which could capture the overall settlement but ignored the effect of freezing temperatures on biodegradation-induced settlement. The second model was a composite model with a primary compression ratio, and rheological and first-order decay equations. The model failed to accurately simulate mechanical creep and account for the effect of freezing temperatures. A modified version, with mechanical creep expressed as a function of the applied stress, was proposed and showed improved settlement predictions. The third model was a Generalized Kelvin-Voigt (GKV) model with biodegradation-induced strain expressed as a function of waste expended energy. This model could simulate the field settlement by considering resistance to compressibility and effects of freezing temperatures. The final model was based on the Modified Cam-Clay (MCC) model. Several studies in the literature have extended the MCC yield surface by incorporating specific mechanical and biological creep models. In this study, a general procedure was proposed to integrate time-dependent strain into the MCC yield surface, irrespective of the mechanical and biological creep models used. The extended MCC model revealed an unrealistic increase in preconsolidation pressure, resulting in an initial elastoplastic response followed by a pure elastic response. It also provided a poor estimation of the field settlement., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Rapid characterization of solid waste using near-infrared hyperspectral imaging (HSI) coupled with machine learning models has been increasingly investigated to replace the traditional time- and labor-intensive methods. However, contamination by waste-derived leachates or other fractions etc., can cause the spectra evolutions and significantly influences the identification performance, which has not been investigated before. The first attempt was made by using hyperspectral unmixing (HU) to extract the endmember components and demonstrate their contributions (abundance) to solid waste, taking the non-linear reflectance changes due to the O-H vibration of water and unclear variation associated with oil and leachates as an example. The HSI spectra of various solid waste components influenced by pure water, oil and three kinds of leachates were acquired. A novel method based on HU models, including multivariate curve resolution with alternating least squares and state-of-the-art autoencoder architectures (deep learning models), was developed to estimate the spectra of endmembers as well as their abundances in individual pixel. Their spatial distribution overview in solid waste was then yielded. The selected models were validated via an independent test data set, with lower spectral angle distance, 12.3° ± 6.5°, indicating the similarity of the predicted endmembers with real components. And the lowest root of mean square error on endmember distribution maps was 0.17. The non-linear liquid's effects by water and oil on spectra variations of solid waste were clearly illuminated. Additionally, the proposed method can extract information from mixed spectroscopic images and generate reconstructed spectra., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Tremendous amount of sludge is generated annually from freshwater treatment or sewage. The high temperature slagging co-gasification converts the sludge to slag showing the potential application for construction material. In this study, the physico-chemical properties of 4 types of slags generated from the co-gasification of municipal solid waste (MSW) with sludge from freshwater treatment or sewage, and ashes from sludge incineration are comprehensively analyzed. Leaching performance of the sludge-derived slag and mortar (with slag as the fine aggregate), as determined based on Toxicity Characteristic Leaching Procedure (TCLP), batch leaching and column leaching tests, indicates the slag can be considered safe for reutilization. Compressive strength test demonstrates that the mortars perform excellently and have the potential to replace sand in concrete production. The consolidation coefficient of slag (1.6 - 39.1 m 2 /year) is lower than the sandy silt but higher than clay. Additionally, the coefficient of permeability (∼1.96 × 10 -3 m/s), angle of shearing resistance (∼39°), and undrained shear strength (375.5 ± 54.8 kPa) of the slag are comparable to sand. The life cycle assessment (LCA) is also conducted to evaluate the environmental impacts and benefits of reutilizing sludge-derived slag as an alternative material for concrete production and land reclamation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The co-firing technology of combustible solid waste (CSW) and coal in the supercritical CO 2 (S-CO 2 ) circulating fluidized bed (CFB) can effectively deal with domestic waste, promote social and environmental benefits, improve the coal conversion rate, and reduce pollutant emission. This study focuses on the co-firing characteristics of CSW and coal under S-CO 2 power cycle, and simulations are conducted by employing Multiphase Particle-in-cell (MP-PIC) method integrated with the comprehensive chemical reaction models in a 300 MW S-CO 2 CFB boiler. Effects of operating parameters including fuel mixture proportion and first stage stoichiometry on the gas emission characteristics are further analyzed. Based on training and testing database based on the simulation results, a novel Improved Whale Optimization Algorithm and Bi-dictionary Long Short-Term Memory (IWOA-BiLSTM) algorithm model is established to predict CFB temperature, NOx emission concentration, and SO 2 emission concentration, respectively. Results show that CO and SO 2 decrease with the coal mass ratio of the fuel mixture increasing, while NOx increases. With the increase of first stage stoichiometry, CO increases, NOx declines, and the change of SO 2 is not obvious. Compared with two other basic algorithm models, the prediction error of the proposed algorithm model for the three targets is minimal with the average relative error of 0.032 %, 0.231 %, and 0.157 %, respectively, which can meet the prediction requirements with acceptable accuracy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Municipal solid waste management (MSWM) in Ethiopia is a complex issue with institutional, social, political, environmental, and economic dimensions, impacting sustainable development. Effective MSWM planning necessitates understanding the generation rate and composition of waste. This systematic review synthesizes qualitative and quantitative data from various sources to aggregate current knowledge, identify gaps, and provide a comprehensive understanding of municipal solid waste management in Ethiopia. The findings reveal that the generation rate of municipal solid waste in Ethiopia is 0.38 kg/ca/day, with the waste composition being predominantly food waste, followed by ash, dust, and sand, and yard waste. Over 85% of this MSW is either reusable or recyclable, with a significant portion being organic matter (73.13% biodegradable) and 11.78% recyclable materials. Physicochemical analyses reveal that Ethiopian MSW is suitable for composting and biogas production, offering opportunities to reduce environmental pollution, and GHGs, support urban agriculture, and create job opportunities. However; challenges persist, including a lack of political will, weak municipal planning, limited community awareness, and inadequate waste management infrastructure, and only 31.8% of MSW is collected legally, leading to inefficient and harmful disposal practices. To improve MSWM, Ethiopia should focus on public awareness; increased funding, infrastructure investment, private sector partnerships, and implementing the 4 R principles (reduce, reuse, and recycle). An integrated approach involving government, industry, and civil society is essential. Further research on the physicochemical properties and strategic uses of MSW is needed to enhance management practices. Implications: The comprehensive study of municipal solid waste management (MSWM) in Ethiopia reveals the intricate interplay of institutional, social, political, environmental, and economic factors that influence the nation's sustainable development. The findings underscore the urgent need for tailored, integrated waste management strategies that are informed by a thorough understanding of MSW generation rates, composition, and current management practices. Ethiopia's lower per capita MSW generation compared to developed countries and the predominantly organic composition of its waste present significant opportunities for sustainable waste management practices such as composting and recycling. These practices can not only minimize the environmental impact but also support urban greening, agriculture, and renewable energy production. The high organic content, suitable physicochemical properties of MSW for composting, and potential for biogas and briquette production highlight pathways for creating employment, reducing waste, and enhancing soil fertility. Despite these opportunities, Ethiopia faces substantial challenges due to inadequate political will, weak municipal planning, limited community awareness, insufficient waste management infrastructure, and poor policy implementation. The high rate of illegal waste disposal further exacerbates environmental and health issues, emphasizing the need for a more effective and integrated MSWM approach. To address these challenges and harness the potential of MSW, Ethiopia must prioritize increasing public awareness; investing in infrastructure, fostering private sector partnerships, and implementing the principles of reduce, reuse, and recycle (3 R). Developing strategies that involve all stakeholders and turning waste into valuable resources is crucial. Government, industry, and civil society must collaborate to implement integrated MSWM systems that focus on waste reduction at the source, alternative material use, and advanced recycling technologies. Further research at both federal and regional levels is essential to optimize the physicochemical analysis and strategic use of MSW. Prompt action is required to transform waste management into a pillar of sustainable urban development, ultimately improving environmental quality and human health in Ethiopia.

With the acceleration of industrialization and population growth, there has been a notable surge in municipal solid waste (MSW) production globally. This necessitates the development of efficient waste management strategies that align with sustainable economic, environmental, and social goals. Implementing sorting and source separation policies serves as foundational steps toward optimizing material flow and resource utilization. In industrial areas, waste generation around a primary source may improve policy implementation and participation. Given the unique strategic context of port environments, Bahregan Port in Iran was selected as a case study to evaluate the proposed methodology. Three integrated scenarios were formulated and prioritized using the ELECTRE-I model: currently practiced collection method, and segregated collection followed by source separation of MSW into two or three groups. The analysis identified the third scenario as the most effective approach. Remarkably, when evaluating the results under optimistic and pessimistic conditions, the ranking of preferences remained consistent across scenarios in the optimal state. Under pessimistic conditions, all scenarios received identical scores, indicating significant uncertainty in criteria weights. Furthermore, sensitivity analysis revealed that criteria such as the raw material sources protection, emissions in the waste separation sector, and greenhouse gas emissions were highly influential. Interestingly, criteria with the highest weighting did not always dictate the final scenario selection. External factors, such as expert opinions on specific criteria, played a pivotal role in scenario prioritization. This research serves as a foundational study for source separation initiatives, offering practical and technically viable strategies to enhance environmental sustainability within industrial settings. Implications : Rising industrialization and population growth have led to increased municipal solid waste (MSW) production worldwide. To address this, efficient waste management strategies are essential, focusing on sustainability and resource optimization through sorting and source separation policies. By prioritizing the scenario of segregated collection followed by source separation - industrial areas can optimize material flow and resource utilization. The study highlights the influence of criteria like raw material protection, emissions, and greenhouse gases, making this research foundational for enhancing environmental sustainability in industrial settings. This study provides practical strategies for enhancing environmental sustainability in industrial settings through source separation initiatives.

Diversion of the organic fraction of municipal solid waste (OFMSW) from landfills is increasing. Previous life cycle assessment studies have evaluated subsets of OFMSW management options, but conclusions are inconsistent, and none have evaluated diverse applications of material by-products. The primary objective of this work was to identify sustainability-based improvements to the selection, design, implementation, and operation of organics waste diversion management technologies. Process modeling and life cycle assessment were used to compare OFMSW composting, anaerobic digestion, and pyrolysis, with biochar used as a landfill cover, leachate treatment sorbent, and land applicant. Material and energy flows, calculated by newly developed models for the defined functional unit (1 kg MSW over a 20-year timeframe), were translated to environmental performance using ecoinvent and USLCI databases and TRACI method. Additionally, uncertainty, sensitivity, and scenario analyses were conducted to evaluate the implications of model uncertainties, design decisions, and resource recovery tradeoffs. OFMSW pyrolysis usually (65 % of uncertainty assessment simulations) had the best global warming performance mostly due to energy recovery and biochar's carbon sequestration benefit, which was independent of fate. Pyrolyzing the biosolids from OFMSW anaerobic digestion recovered the most energy and had the best performance in 34 % of uncertainty simulations. Material recovery amounts were large (e.g., more biochar was produced than required for novel uses) and warrant feasibility considerations. Global warming performance was more sensitive to uncertainty in carbon sequestration and primary energy production than in fertilizer offset, energy conversion, or heat offset approach. Practical implications include the potential for biochar supply to outweigh demand, and inconsistent revenue from the sale of recovered energy and carbon credits; future research could focus on evaluating the relative social and economic sustainability of the OFMSW management technologies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The analysis of the presence and content of substances that are toxic to aquatic life in waste is essential for classification of waste with regard to hazard property (HP) 14 'ecotoxic'. For the determination of HP14 classified copper (Cu) and zinc (Zn) compounds in various municipal solid waste incineration bottom ashes (IBA) and one fly ash (FA) from Germany we applied X-ray absorption near-edge structure (XANES) spectroscopy in combination with linear combination fitting. The analysis showed that approx. 50-70% of Cu in the IBA are Cu(I) compounds and elemental Cu(0), but these compounds were not equally distributed in the different IBA. In contrast, the majority (approx. 50-70%) of Zn in all IBA is elemental zinc, which originates from brass or other alloys and galvanized metals with a large content of zinc in the waste. The FA contain higher mass fraction on Zn and other toxic elements, but similar Cu and Zn species. Additional performed selective extraction at a pH of 4 with an organic acid of some IBA showed that the ecotoxic Zn fraction is mainly elemental zinc and zinc oxide. In contrast, for the ecotoxic Cu fraction within the IBA no specific compound could be identified. Furthermore, the XANES analysis showed that the HP14 properties of especially Cu in IBA is overestimated with current best-practice guidelines for sample processing for the current substance-related approach with the 0.1% cut-off rule for each substance. However, it should be considered whether it would not be better from an environmental point of view to take the ecotoxicologically leachable copper and zinc as a reference value., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

This study proposes a comprehensive evaluation method based on a two-stage model to assess greenhouse gas (GHG) emissions and reductions in high-food-waste-content (HFWC) municipal solid waste (MSW) landfills. The proposed method considers typical processes such as fugitive landfill gas (LFG), LFG collection, flaring, power generation, and leachate treatment. A case study of an HFWC MSW landfill in eastern China is considered to illustrate the evaluation. The findings revealed that the GHG emissions equivalent of the case landfill amounted to 21.23 million tons from 2007 to 2022, averaging 1.03 tons CO 2 -eq per ton of MSW. There was a potential underestimation of LFG generation at the landfill site during the initial stages, which led to delayed LFG collection and substantial fugitive LFG emissions. Additionally, the time distribution of GHG emissions from HFWC MSW was significantly different from that of low-food-waste-content (LFWC) MSW landfills, with peak emissions occurring much earlier. Owing to the rapid degradation characteristics of HFWC MSW, the cumulative LFG production of the landfill by 2022 (2 years after the final cover) was projected to reach 77 % of the total LFG potential. In contrast, it would take until 2030 for LFWC MSW landfills to reach this level. Furthermore, various scenarios were analyzed, in which if the rapid LFG generation characteristics of HFWC MSW are known in advance, and relevant facilities are constructed ahead of time, the collection efficiency can be improved from 31 % to over 78 %, resulting in less GHG emissions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

High-solid digestion (HSD) for biogas production is a resource-efficient and sustainable method to treat organic wastes with high total solids content and obtain renewable energy and an organic fertiliser, using a lower dilution rate than in the more common wet digestion process. This study examined the effect of reactor type on the performance of an HSD process, comparing plug-flow (PFR) type reactors developed for continuous HSD processes, and completely stirred-tank reactors (CSTRs) commonly used for wet digestion. The HSD process was operated in thermophilic conditions (52 °C), with a mixture of household waste, garden waste and agricultural residues (total solids content 27-28 %). The PFRs showed slightly better performance, with higher specific methane production and nitrogen mineralisation than the CSTRs, while the reduction of volatile solids was the same in both reactor types. Results from 16S rRNA gene sequencing showed a significant difference in the microbial population, potentially related to large differences in stirring speed between the reactor types (1 rpm in PFRs and 70-150 rpm in CSTRs, respectively). The bacterial community was dominated by the genus Defluviitoga in the PFRs and order MBA03 in the CSTRs. For the archaeal community, there was a predominance of the genus Methanoculleus in the PFRs, and of the genera Methanosarcina and Methanothermobacter in the CSTRs. Despite these shifts in microbiology, the results showed that stable digestion of substrates with high total solids content can be achieved in both reactor types, indicating flexibility in the choice of technique for HSD processes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Solid waste incineration is a clean and sustainable approach for solid waste management. However, ash deposition and corrosion remain a critical issue due to fuel's inherent enrichment of alkali chlorine. This study develops an integrated online deposition and corrosion monitoring system to enhance the operational safety and efficiency of solid waste incineration boilers. This system combines linear polarization resistance (LPR) for corrosion rate estimation with heat flux measurements for ash deposition analysis. It can offer a novel approach for real-time monitoring of heat exchangers' safety during solid waste combustion. It was deployed in a full-scale circulating fluidized bed (CFB) boiler that purely combust solid wastes. Key findings demonstrate the system's capability to deliver continuous, real-time data, crucial for the dynamic control of combustion processes and the maintenance of heat transfer surfaces. Its robust diagnostic capabilities were evident across various scenarios. Specially, initial corrosion rates sharply increase with deposition rates due to the enrichment of alkali chlorine on inner deposit layer, in which chlorine serves as a catalyst, facilitating the rapid penetration and aggravation of corrosion by other agents. As deposit further buildup, the corrosion rate steadily decreases along with surface temperature, highlighting a dynamic interaction. Moreover, measured corrosion rates can quickly response to temperature variations. Such multi-process online monitoring system provide more possibilities to investigate the inherent interaction between deposition and corrosion. Therefore, this work offers insights that could significantly influence operational strategies, maintenance protocols, and the overall reliability of waste-to-energy technologies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Paper packaging made with recycled paperboard is used to pack various consumer goods that can include amongst others, electronics, toys, food, cosmetics, and stationery. Chemical profiling of the various paper recycling grades used in the manufacture of recycled paperboard was undertaken to investigate possible sources of contaminants and their propagation in the paper recycling chain. Pre-consumer, retail and post-consumer paper-based materials were collected at papermills, corrugators, grocery stores, household waste, solid waste disposal sites and recycling facilities. In the GC-MS analysis, phthalates, long-chain aliphatic compounds, and fatty acids were the most commonly detected compounds whilst phthalates and bisphenols featured most prevalently in the LC-MS analysis. The factors that were identified as likely contributors to the detection of the different chemical compounds included the presence of wood derivatives, the use of certain chemical additives during manufacturing, and exposure of paper to contaminants from consumers, other goods and the environment. Waste mingling, recovery, sorting and reprocessing into recycled paper were also shown to influence the chemical profile of paper materials. Sparse partial least squares-discriminate analysis indicated that newspaper and office paper had unique chemical constituents, whilst cartons were shown to have higher variability. By looking at key stages of paper recycling, this study showed that the possible persistence and transformation of chemical compounds in additives must be evaluated when considering the recyclability of paper-based materials. Further, it highlighted that different separation approaches may be required to reduce contaminant exposure opportunities in post-consumer paper materials., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

This study used the horizontal tubular heating furnace to explore the melting potential of circulating fluidized bed (CFB) incinerator fly ash and mechanical grate furnace (MGF) incinerator fly ash. The horizontal cyclone melting furnace was then built to explore further the feasibility of scale melting of MSWI fly ash. The melting characteristic temperature, amorphous content, and heavy metal leaching concentration characterized the melting potential and solidification effect of MSWI fly ash. The experimental results show that the amorphous content of CFB fly ash after melting is up to 92.37%, and the volatilization rate of heavy metals Zn, Pb, and Ni does not exceed 30%. MGF fly ash exhibits the "sintering into shells" phenomenon during heating, and the leaching concentrations of heavy metals Pb in the sintered products still exceed the standard limits. In addition, the volatilization rates of heavy metals Cu, Zn, Cd, Pb, Cr, and Ni in Slag II are above 50%, and the volatilization rate of Cr reaches 85%. So, slag's amorphous content also affects heavy metals' volatilization rate. The MSWI fly ash melting characteristic temperature decreases with the decrease of alkalinity value. When the alkalinity value drops to 0.6, the melting characteristic temperature reaches its lowest value. Mixing 80% CFB fly ash or 50% MGF bottom ash into MGF fly ash can significantly enhance the melting potential to reduce hazardous waste. When using the horizontal cyclone melting furnace to process MSWI fly ash on a large scale, MSWI fly ash achieves an excellent melting effect with an amorphous content of over 93% at the positions of the furnace middle section, inner tail cone, slag discharge outlet, and flue gas outlet. The fly ash particles are in motion in the melting furnace, so the particle size distribution affects the melting effect of MSWI fly ash., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study optimized the anaerobic digestion (AD) of separated collected organic fractions of municipal solid waste (OFMSW) to produce energy and digestate as biofertilizer. Due to OFMSW's partial recalcitrance to degradation, enzymatic (UPP2, MCPS, USC4, USE2, A. niger) and physical (mechanical blending, heating, hydrodynamic cavitation) pre-treatments were tested. Experimental and modeling approaches were used to compare AD performance regarding energy sustainability and digestate quality. Digestate was separated into solid and liquid fractions, and then chemically and physically characterized by investigating the nutrient release mechanisms. Principal Component Analysis was applied, equally weighing energy and digestate productions. Unlike previous studies focusing only on biogas, this study evaluated the effects of pre-treatments on both biogas and digestate production, viewing AD as a biorefinery process for urban waste valorization. Results showed that all pre-treatments were energetically sustainable, but enzymatic pre-treatments yielded digestates richer in nutrients (increase of 80% N, 200% P and 150% K as compared to OFMSW) and with greater organic matter degradation compared to physical pre-treatments. The liquid fraction of digestate from enzymatic pre-treatments had higher nutrient concentrations, while those from physical pre-treatments had more balanced nutrient content, making them more suitable for fertigation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The detection and characterization of illegal solid waste disposal sites are essential for environmental protection, particularly for mitigating pollution and health hazards. Improperly managed landfills contaminate soil and groundwater via rainwater infiltration, posing threats to both animals and humans. Traditional landfill identification approaches, such as on-site inspections, are time-consuming and expensive. Remote sensing is a cost-effective solution for the identification and monitoring of solid waste disposal sites that enables broad coverage and repeated acquisitions over time. Earth Observation (EO) satellites, equipped with an array of sensors and imaging capabilities, have been providing high-resolution data for several decades. Researchers proposed specialized techniques that leverage remote sensing imagery to perform a range of tasks such as waste site detection, dumping site monitoring, and assessment of suitable locations for new landfills. This review aims to provide a detailed illustration of the most relevant proposals for the detection and monitoring of solid waste sites by describing and comparing the approaches, the implemented techniques, and the employed data. Furthermore, since the data sources are of the utmost importance for developing an effective solid waste detection model, a comprehensive overview of the satellites and publicly available data sets is presented. Finally, this paper identifies the open issues in the state-of-the-art and discusses the relevant research directions for reducing the costs and improving the effectiveness of novel solid waste detection methods., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Waste management researchers have identified that the correct disposal of solid waste is better addressed upstream, where people properly sort their solid waste. Sorting solid waste is a practice that requires a behaviour friendly to sorting and willingness to continuously comply with waste management policies. However, the dynamic and ever-changing nature of service buildings' users makes fostering such behaviour challenging, potentially jeopardizing solid waste sorting efforts. Therefore, in this paper, we explore the possible role of artificial intelligence in alleviating the cumbersome process of sorting solid waste, by developing a virtual assistant that interacts with tenants via verbal and visual inputs to provide them with waste management services and instructions. The virtual assistant utilizes Natural Language Processing and computer vision techniques to enable voice and image recognition functionalities and achieved accuracy levels of 85% and 88% for verbal and visual inputs, respectively. The present work can be a solid foundation to investigate further implementation of virtual assistants to support sustainability practices in Facility Management., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Various anthropogenic activities affect marine coastal habitats, leading to heavy litter pollution. However, whilst high litter concentrations are nowadays common in the proximity of metropolises, few studies investigated the magnitude of this phenomenon around coastal villages and small towns. We hereby characterized the benthic litter occurring in the trawlable grounds of the Gulf of Policastro (Tyrrhenian Sea, central-western Mediterranean), a low population density area that becomes a popular tourist destination during summer. We furthermore tested differences between two depths (∼100-200 and ∼500-600 m) and the impact of tourism on the shallower waters. The area was characterized by a litter abundance of 651.12 ± 130.61 item/km 2 , with plastic being almost totalitarian (93%). The shallower waters hosted two-thirds of the litter found. Almost all (∼95%) the litter items had a land-based origin, while the sea-based litter was mostly found at higher depths. About 14% of the litter was found to be fouled, with the development of litter-associated communities that somehow mimic the natural ones living on hard substrates. The higher litter presence noticed during the touristic peak (July-August) suggests that tourism is an important source of local litter, although it contributed to the local accumulation in a synergic way with other factors. The majority of the litter items presumably originated from the nearby coastline, while the deeper waters were or are used as a dumping site by the local trawling fleet. The discovery of such a critical waste accumulation and management in a somehow remote area contributes to widen the perspectives on the presence of benthic litter mostly in territories characterized by wide anthropization. Moreover, it confirms that appropriate local policies and communication plans are urged even at a regional level to stimulate citizen consciousness and mitigate the ever growing litter pollution., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Lucia Rizzo, Pierpaolo Consoli, and Fabio Crocetta report that financial support was provided by the Campania Region. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The rapid growth of organic solid waste has recently exacerbated environmental pollution problems, and its improper treatment has led to the loss of a large number of biomass resources. Here, we expound the advantages of microbial agents composting compared with conventional organic solid waste treatment technology, and review the important role of microbial agents composting in organic solid waste composting from the aspects of screening and identification, optimization of conditions, mechanism of action, combination with other technologies and ultra-high-temperature and ultra-low-temperature microbial composting. We discuss the value of microorganisms with different growth conditions in organic solid waste composting, and put forward a seasonal multi-temperature composite microbial composting technology. Provide new ideas for the all-round treatment of microbial agents in organic solid waste in the future. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

The whopping increase in solid waste landfills poses serious threats to the environment. Compared to the drilling method, geophysical methods are effective, non-invasive techniques for delineating the contaminant distribution. In this study, electrical resistivity tomography (ERT) and induced polarization (IP) were used to investigate a solid waste deposit. The results of ERT/IP imaging illustrate the potential of the method in environmental studies. Based on the results of 21 survey lines, geo-electrical signals can be summarized as three types: with only high resistivity for construction & demolition wastes (CDWs) areas (RO type), contaminated soil for high chargeability (CO type), and contaminants under CDWs layer have both high resistivity and chargeability (RC type). Chargeability values over 10.2 mV/V correspond to contaminated soil with an overall concentration larger than 75 mg/kg. With the three-dimensional interpolation results and the determined chargeability criteria, the total volume of contaminated soil is 40,555 cubic meters. Finally, comparing the efficiency, cost and results of IP and drilling sampling methods shows that the IP is an efficient, low-cost and high-resolution contamination characterization. The results support that ERT/IP information can fulfill rapid and initial identification as a reliable tool in engineering and environmental investigations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Organic fertilizers have become a vector for the transport of microplastics (MPs), which pose human health concerns through the food chain. This study aimed to quantify and characterize MPs in eight different compost samples of various raw materials and their subsequent translocation to lettuce (Lacuta sativa) grown on contaminated composts. The results revealed that the MP abundance ranged from 3810 to 16530 MP/kg. Municipal solid waste compost (MSWC) had highest abundance (16082 ± 632 MP/kg), followed by leaf compost (LC) and organic compost (OC) (6299 ± 1011 and 3680 ± 419 MP/kg, respectively). MPs of <100 μm in size were most dominant in MSWC and LC. Fragments and fibers were the prevalent shape types, with white/transparent colored MPs being more abundant. Polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET) were the dominant polymers. MPs accumulation in the lettuce leaves was greatest in the lettuce plants grown on MSWC, followed by those grown on LC and OC, indicating that MSWC grown lettuce is not suitable for human consumption. The decrease in the growth (leaf length, number of leaves, leaf fresh and weights) and physiological (membrane stability index, relative water contents) parameters of lettuce was in line with the trend of MP accumulations. Hence, it is highly important to regulate the plastic contents in compost because it is a threat to ecosystems and human health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

A novel and environmentally friendly magnetic iron zeolite (MIZ) core-shell were successfully fabricated using municipal solid waste incineration bottom ash-derived zeolite (MWZ) coated with Fe 3 O 4 and innovatively investigated as a heterogeneous persulfate (PS) catalyst. The morphology and structure composition of as-prepared catalysts were characterised, and it was proved that the core-shell structure of MIZ was successfully synthesised by coating Fe 3 O 4 uniformly on the MWZ surface. The tetracycline hydrochloride (TCH) degradation experiment indicate that the optimum equimolar amount of iron precursors was 3 mmol (MIZ-3). Compared with other systems, MIZ-3 possessed a superior catalytic performance, and the degradation efficiency of TCH (50 mg·L -1 ) in the MIZ-3/PS system reached 87.3%. The effects of reaction parameters on the catalytic activity of MIZ-3, including pH, initial concentration of TCH, temperature, the dosage of catalyst, and Na 2 S 2 O 8 , were assessed. The catalyst had high stability according to three recycling experiments and the leaching test of iron ions. Furthermore, the working mechanism of the MIZ-3/PS system to TCH was discussed. The electron spin resonance (ESR) results demonstrated that the reactive radicals generated in the MIZ-3/PS system were sulphate radical ( S O 4 - ∙ ) and hydroxyl radical (•OH). This work provided a novel strategy for TCH degradation under PS with a broad perspective on the fabrication of non-toxic and low-cost catalysts in practical wastewater treatment.

This study comprehensively evaluates Jordan's municipal solid waste (MSW) management sector from 2022 to 2030, in alignment with Jordan Vision 2030. This study introduces new sustainability indicators and innovative waste management alternatives to address the challenges of rapid industrialization and population growth. Four strategic scenarios-1) recycling, composting, and sanitary landfilling; 2) recycling, anaerobic digestion, and sanitary landfilling; 3) incineration and sanitary landfilling; and 4) sanitary landfilling alone-were assessed against the business-as-usual scenario. Using multi-criteria decision analysis (MCDA) and sensitivity analysis, this study evaluates net greenhouse gas emissions, annual operating expenses, revenue streams, and employment rates to measure environmental, economic, and social sustainability. The results indicate that Scenario 1 is the optimal scenario for integrating a material recovery facility (MRF) with a composting plant and sanitary landfill, achieving the lowest greenhouse gas emissions, annual costs, and employment opportunities. This study offers practical and sustainable solutions to Jordan's waste management challenges, provides novel insights through the developed MCDA and sensitivity analysis, and significantly contributes to sustainability research., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Effective municipal solid waste (MSW) management is a crucial component for sustainable cities, as inefficient waste disposal contributes to the release of about a billion tons of CO 2 -eq in greenhouse gases (GHG) annually. With escalating global waste generation, there is an untapped opportunity to integrate carbon dioxide removal (CDR) technologies into existing MSW management processes. This review explores current research on utilizing MSW for CDR, emphasizing its potential for both energy generation and carbon sequestration. The investigation covers three waste management practices: landfilling, waste-to-energy (WtE), and biochar production, revealing two paths for carbon sequestration. First, MSW serves as a feedstock in bioenergy with carbon capture and storage (BECCS), acting as a carbon-neutral resource that avoids fossil fuel and energy crop use, reducing GHG emissions and generating value through energy production. Second, direct storage of organic MSW and its derivatives, like biochar, in various carbon sinks allows for extended sequestration, offering a comprehensive approach to address the challenges of waste management and climate change mitigation. Moreover, this review advocates for an extended exploration into several subjects including in-depth analysis of waste, research on MSW-derived biochar recalcitrance across different carbon sinks, and understanding the symbiotic connections with GHG-emitting sectors like agriculture and energy. Finally, this review emphasizes the necessity of conducting life-cycle assessment studies to fully discern the benefits and assess the impacts of any future endeavors exploring the role of MSW in carbon sequestration., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Landfills, especially those poorly managed, can negatively affect the environment and human beings through chemical contamination of soils and waters. This study investigates the soils of a historical municipal solid waste (MSW) landfill situated in the heart of a residential zone in the capital of Slovakia, Bratislava, with an emphasis on metal (loid) contamination and its consequences. Regardless of the depth, many of the soils exhibited high metal (loid) concentrations, mainly Cd, Cu, Pb, Sb, Sn and Zn (up to 24, 2620, 2420, 134, 811 and 6220 mg/kg, respectively), classifying them as extremely contaminated based on the geo-accumulation index (I geo >5). The stable lead isotopic ratios of the landfill topsoil varied widely (1.1679-1.2074 for 206 Pb/ 207 Pb and 2.0573-2.1111 for 208 Pb/ 206 Pb) and indicated that Pb contained a natural component and an anthropogenic component, likely municipal solid waste incineration (MSWI) ash and construction waste. Oral bioaccessibility of metal (loid)s in the topsoil was variable with Cd (73.2-106%) and Fe (0.98-2.10%) being the most and least bioaccessible, respectively. The variation of metal (loid) bioaccessibility among the soils could be explained by differences in their geochemical fractionation as shown by positive correlations of bioaccessibility values with the first two fractions of BCR (Community Bureau of Reference) sequential extraction for As, Cd, Mn, Ni, Pb, Sn and Zn. The results of geochemical fractionation coupled with the mineralogical characterisation of topsoil showed that the reservoir of bioaccessible metal (loid)s was calcite and Fe (hydr)oxides. Based on aqua regia metal (loid) concentrations, a non-carcinogenic risk was demonstrated for children (HI = 1.59) but no risk taking into account their bioaccessible concentrations (HI = 0.65). This study emphasises the need for detailed research of the geochemistry of wastes deposited in urban soils to assess the potentially hazardous sources and determine the actual bioaccessibility and human health risks of the accumulated metal (loid)s., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Plastics within municipal solid waste (MSW) are non-degradable. As MSW continues to degrade, the relative content of plastics rises, and particle gradation may also change. Moreover, throughout the landfilling process, MSW is subjected to various stress conditions, potentially influencing its mechanical properties. This study explored the effects of varying plastic contents, different particle gradations, and distinct stress paths on the mechanical properties of MSW, and consolidated drained triaxial tests of 42 groups of reconstituted MSW specimens were conducted. The results showed that there was an optimal plastic content of 6-9 % for MSW, where the shear strength of MSW was higher than that of MSW with other plastic contents. When the stress path changed from TC45 to TC72, the optimal plastic content of MSW changed from 6 % to 9 %. As the plastic content increased, both the cohesion and internal friction angle of the MSW initially increased, then subsequently decreased. The impact of plastic content on cohesion was more pronounced than on the internal friction angle, especially at larger strains. Under various stress paths, MSW with distinct particle size distributions demonstrated diverse stress-strain behaviors. Traditional criteria for evaluating well-graded conditions in soils are not suitable for MSW. The effect of gradation on the cohesion of MSW is essentially due to the predominant role of fiber content; the relationship between gradation and the internal friction angle in MSW is complex and correlates closely with the content of both coarse and fine particles, as well as fibers. This study serves as an essential reference for predicting deformations in landfills and analyzing the stability of landfill slopes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The low recycling rate of post-consumer plastic packaging waste (PPW), which is partly due to insufficient separate collection, heterogeneous composition and high levels of contamination, poses a challenge in Austria, where the recycling rate must double in order to meet the target of 55 %. This study analyzes key packaging characteristics of non-beverage plastic bottles influencing recyclability, using Vienna as a case study. Additionally, a net quantity indicator and separate collection rates were calculated. 738 bottles from mixed MSW and 1,159 bottles from separate PPW collection were analyzed. The main polymer's proportion described by the net quantity indicator was higher for bottles from separate collection (69-72 %) than from mixed MSW (58 %), showing that a large share of the foreign materials are residues and dirt, with significantly higher contents in mixed MSW (20 %) than in separate collection (11 %). With a separate collection rate of 19.2 %, the great potential for recycling currently lies in mixed MSW at 4,112 t/yr. Thereof, 46 % is uncolored, 54 % is colored/white and, in terms of material grade, 30 % is food grade. The most common filling volume for PET, PP and HDPE was 0.5 < x ≤ 1.5 L (23-59 %) and the most common decoration technology was label (60-85 %). PET and PP had the highest shares of food-grade bottles (37-46 %), while PP had the highest share of colored bottles (22-31 %). The mechanical recycling potential of bottles depends largely on packaging characteristics, influencing separate collection and also automatic sorting. Harmonized design specifications are therefore crucial for this heterogeneous PPW fraction., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Higher heating value (HHV) is one of the most important parameters in determining the quality of the fuels. In this study, comparatively large datasets of ultimate and proximate analysis are constructed to be used in HHV estimation of several classes of fuels, including char & fossil fuels, agricultural wastes, manure (chicken, cow, horse, sheep, llama, and pig), sludge (like paper, paper-mil, sewage, and pulp), micro/macro-algae's, wastes (RDF and MSW), treated woods, untreated woods, and others (non-fossil pyrolysis oils) between the HHV range of 4.22-55.55 MJ/kg. The relationships of carbon, hydrogen, and oxygen atomic ratios for fuel classes are illustrated by using ternary plots, and the effects of elemental composition on HHV was analyzed with the extensive dataset. Then, the ultimate (U) and ultimate & proximate (UP) datasets were utilized separately to estimate the HHV by using artificial neural networks (ANN). Hyperparameter optimization was carried out and the best performing ANNs were determined for each dataset, which yielded R 2 values of 0.9719 and 0.9715, respectively. The results indicated that while ANNs trained by both datasets perform remarkably well, utilization of U dataset is sufficient for HHV estimation. Finally, the best performing ANN models for both U and UP datasets are given in a directly utilizable format enabling the accurate estimation of HHV of any fuel for optimization of fuel processing and waste management operations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The soil, comprising minerals, organic matter, and living organisms, serves as a critical component of our environment. However, anthropogenic activities, such as uncontrolled sewage disposal and industrial waste, have led to pervasive soil pollution, impacting ecosystems and human health. This comprehensive study scrutinizes the intricate dynamics of soil pollution resulting from open waste dumping, specifically examining its impact on the health of local communities and the environment in Haridwar municipality. In this study, four solid waste dumping sites were meticulously surveyed, with soil samples analyzed for 19 parameters through statistical tools like one-way ANOVA, Kruskal-Wallis tests, soil pollution indices, and potential health risk assessment. The Geo-accumulation Index (Igeo) and contamination factor (CF) followed the heavy metals in the order of Zn > Mn > Fe > Cu in all selected sites. Additionally, a potential health risk assessment considered ingestion, inhalation, and dermal exposure pathways, revealing a high non-carcinogenic risk of metals (Mn > Fe > Zn > Cu) for both children and adults. In the ingestion pathway, the hazard quotient indicated a high risk of metals for both children and adults in the range of 1192.73 to 2066.94 for child and 191.98 to 312.16 for adults. Crucially, the HQ revealed potential health risks, emphasizing the urgency of addressing metal contamination. However, the findings indicate that dumping sites directly or indirectly affects the local people of Haridwar municipality. Therefore, this study provides a baseline framework for minimizing the impact of dumping sites on local population and the environment., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Municipal solid waste (MSW) landfill sites have been identified as a significant source of pharmaceuticals in the environment because unused or expired pharmaceuticals are discarded into MSW, which eventually percolate into leachates. However, the contamination of pharmaceuticals in landfill leachate in China is not comprehensively understood. Previous research into factors influencing pharmaceutical concentrations focused on a limited number and type of target pollutants or restricted study area. In the present study, 66 pharmaceuticals were analyzed (including 45 antibiotic and 21 non-antibiotic pharmaceuticals, also categorized as 59 prescription and 7 non-prescription pharmaceuticals) in leachate samples from landfill sites with various characteristics in different regions of China. The results indicated that non-antibiotic pollutants were present at significantly higher concentrations than antibiotic pollutants, with median concentrations of 1.74 μg/L and 527 ng/L, respectively. Non-antibiotic pollutants also presented a higher environmental risk than antibiotic pollutants, by 2 to 4 orders of magnitude, highlighting that non-antibiotic pharmaceuticals should not be overlooked during the assessment of landfill leachate. Pharmaceutical concentrations in landfill leachate samples exhibited regional differences; the population size served by the landfills was the dominant factor contributing to the observed differences. In addition, landfill characteristics such as the solid waste composition and MSW loading can also affect pharmaceutical concentrations in landfill leachate. Despite the implementation of the classification and disposal policy of MSW in Shanghai, China since July 2019, specifying that unused or expired pharmaceuticals should be discarded as hazardous waste, high levels of pharmaceutical contaminations were detected in leachate from the main components of classified MSW (i.e., residual and food waste). These findings emphasize the importance of pharmaceutical management in solid waste systems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Simulated landfill bioreactors were established and operated for 635 days to investigate the dynamic release of seven siloxanes in landfill biogas (denoted by octamethyltrisiloxane (L3), decamethyltetrasiloxane (L4), dodecamethylpentasiloxane (L5), hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6)). In total, 259.45, 252.73, 233.30, 80.40, 4.35, 1.67 and 1.10 mg of D5, D3, D4, D6, L4, L5 and L3 were discharged from 57 kg of municipal solid waste (MSW). More than 70 % of the siloxanes were released before day 119, indicating that the peak period of siloxane discharge occurred during the hydrolysis and acid production stage. The cyclosiloxanes (D3, D4, D5 and D6) were the dominant siloxane species in the biogas. The mass load of discharged cyclosiloxanes was more than 98 % of that of the total siloxanes. In addition to the variation in the concentration distribution profiles of the different siloxane species in the MSW, transformations among species may have an important effect on the release of siloxanes. The main transformation products were D3 and D4 with high release rates (>20 %) and high measured contents of trimethylsilanol (TMSOH) and functional microorganisms (Pseudomonas) were observed during landfilling. These results suggested that MSW degradation and transformation of siloxanes both drive the dynamic release of siloxanes during long-term landfilling., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The increasing application of municipal solid waste incineration (MSWI) emphasises the need for MSWI fly ash (FA) safe treatment. Based on the compositional complementarity of FA from grate furnaces (G-FA) and fluidised bed incinerators (F-FA), we proposed a co-reduction process to treat G-FA and F-FA together for producing vitrified slag and ferroalloys. The clean vitrified slag and Fe-Cr-Ni-Cu alloy were obtained with the mass ratios of 1:9 ∼ 6:4 (G-FA:F-FA) at 1300℃, which is about 300℃ lower than the conventional G-FA vitrification. The metals Zn, Cd, and Pb were mostly volatilised into the flue gas for potential recovery from the secondary FA. The thermodynamic SiO 2 -Al 2 O 3 -CaO ternary system demonstrated that an optimal mass ratio of the two complementary FA types contributes to the system shifting to the low-temperature melting zone. The co-reduction process of G-FA and F-FA could be a promising option for FA beneficial reutilization with environmental advantages., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Solid waste challenges in both the tungsten and photovoltaic industries present significant barriers to achieving carbon neutrality. This study introduces an innovative strategy for the efficient extraction of valuable metals from hazardous tungsten leaching residue (W-residue) by leveraging photovoltaic silicon kerf waste (SKW) as a silicothermic reducing agent. W-residue contains 26.2% valuable metal oxides (WO 3 , CoO, Nb 2 O 5 , and Ta 2 O 5 ) and other refractory oxides (SiO 2 , TiO 2 , etc.), while micron-sized SKW contains 91.9% Si with a surface oxide layer. The impact of SKW addition on the silicothermic reduction process for valuable metal oxides in W-residue was investigated. Incorporating SKW and Na 2 CO 3 flux enables valuable metal oxides from W-residue to be effectively reduced and enriched as a valuable alloy phase, with unreduced refractory oxides forming a harmless slag phase during the Na 2 O-SiO 2 -TiO 2 slag refining process. This process achieved an overall recovery yield of valuable metals of 91.7%, with individual recovery yields of W, Co, and Nb exceeding 90% with the addition of 8 wt.% SKW. This innovative approach not only achieves high-value recovery from W-residue and utilization of SKW but also minimizes environmental impact through an efficient and eco-friendly recycling pathway. The strategy contributes significantly to the establishment of a resource-efficient circular economy, wherein the recovered high-value alloy phase return to the tungsten supply chain, and the harmless slag phase become raw materials for microcrystalline glass production., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study examined plastics and toxic metals in municipal solid waste compost from various regions in Sri Lanka. Plastics were extracted using density separation, digested using wet peroxidation, and identified using Fourier Transform Infra-Red Spectroscopy in Attenuated Total Reflection mode. Compost and plastics were acid-digested to quantify total Cd, Cu, Co, Cr, Pb, and Zn concentrations and analyzed for the bioavailable fraction using 0.01 M CaCl 2 . Notably, plastics were highly abundant in most compost samples. The main plastic types detected were polyethylene, polypropylene, and cellophane. However, the average Cd, Cu, Co, Cr, Pb, and Zn levels were 0.727, 60.78, 3.670, 25.44, 18.95, and 130.7 mg/kg, respectively, which are well below the recommended levels. Zn was the most bioavailable (2.476 mg/kg), and Cd was the least bioavailable (0.053 mg/kg) metal associated with compost. The Contamination factor data show that there is considerable enhancement of Cd and Cu, however, Cr, Cu, Co, and Pb are at low contamination levels. Mean geo accumulation index values were 1.39, 1.07, - 1.06, - 0.84, - 0.32, and 0.08 for Cd, Cu, Co, Cr, Pb, and Zn. Therefore, the contamination level of compost samples with Cd and Cu ranges from uncontaminated to contaminated levels, whereas Co, Cr, Pb, and Zn are at uncontaminated levels. Despite no direct metal-plastic correlation, plastics in compost could harm plants, animals, and humans due to ingestion. Hence, reducing plastic and metal contamination in compost is crucial., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

The physical and chemical characteristics of fly ash has changed significantly under ultra-low emission system and the current leaching system is no longer suitable for high alkalinity fly ash. This work investigated the pH values and evolution of physical and chemical characteristics of fly ash from 24 typical municipal solid waste incineration plants in China. The pH value of the leaching solution obtained by HJ/T 300-2007 presented two different acid and alkali characteristics, where high and low alkalinity fly ash accounted for 54.17% and 45.83%, respectively. The alkali content in fly ash increased significantly after ultra-low emission standard, increasing by 18.24% compared with before the implementation of GB 18485-2014. The leaching behavior of high alkalinity fly ash showed the illusion that they could enter the landfill only by the addition of a small amount of chelating agent or even without stabilization treatment, and its long-term landfill risk is significant. The phase change of high alkalinity fly ash and pH value change of the leaching solution after carbonation were the key factors for the leaching concentration change of heavy metals. Therefore, it is recommended to improve the existing leaching system or conduct accelerated carbonization experiments to scientifically evaluate the long-term leaching characteristics of high alkalinity fly ash, and to reduce the risk of heavy metal release from high alkalinity FA after entering the landfill site., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Continuous release and migration of heavy metals from coal-based solid waste (CSW) dumpsites often results in significant encroachment on ecological lands and pollution of natural environments. As a result, there is an urgent need for long-term and rapid monitoring, analysis, and assessment to control environmental risks associated with large CSW dumpsites. We constructed a new composite model (PLS-FL) that uses partial least squares regression (PLSR) and fuzzy logic inference (FLI) to accurately predict heavy metal concentrations in soils and assess pollution risk levels. The potential application of the PLS-FL was tested through a gully type CSW case study. We compared 20 modeling strategies using the PLS-FL: five types heavy metals (Cd, Zn, Pb, Cr and As) * four spectral transformation methods (first derivative (FD), second derivative (SD), reverse logarithm (RL), and continuum removal (CR)) * one variable selection method (competitive adaptive reweighted sampling (CARS)). The results showed that the combination of derivative transformation and CARS was recommended for estimation, with R 2 C  > 0.80 and R 2 P  > 0.50. When comparing the PLSR model with four traditional machine learning methods (Support Vector Machines (SVM), Random Forests (RF), Extreme Learning Machines (ELM), and KNN), the PLSR model demonstrated the highest average prediction accuracy. Additionally, the FLI process no longer relies on human perception and expert opinion, enhancing the model's objectivity and reliability. The evaluation results revealed that the heavy metal contamination areas of the CSW dumpsite are concentrated at the bottom of the gully, with more severe contamination in the north. Furthermore, a high-risk zone exists in the interim storage area for CSW to the east of the dump. These findings align with the initial detections at the sampling sites and highlight the need for targeted monitoring and control in these areas. The application of the model will empower regulators to quickly assess the overall situation of large-scale heavy metal pollution and provide scientific program and data support for continuous large-scale pollution risk monitoring and sustainable risk management., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)