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Upcycling food waste into PHAs offers a promising solution to reduce environmental impact and generate value-added products for drug delivery, scaffold materials, and tissue engineering. Lignocellulosic food waste requires pretreatment and detoxification, whereas waste cooking oil can be fermented directly to produce PHAs. Cupriavidus necator excels in PHA production from lignocellulosic feedstock, showing tolerance to inhibitors. Pseudomonas spp. stand out for waste cooking oil utilization owing to their capacity for esterase and lipase production, enabling PHA accumulation. Butyl acetate is the optimal solvent for PHA recovery owing to its high yield, purity, and molecular weight, with minimal toxicity. PHAs can be recycled through methods such as extrusion, pyrolysis, gasification, and anaerobic digestion within a closed-loop cycle. This review emphasizes the urgent need for food waste upcycling as a response to the mounting global food waste crisis. Focusing on polyhydroxyalkanoates (PHAs) as an alternative to traditional plastics, it examines the potential of various food wastes as feedstock for microbial fermentation and PHA production. The upcycling of food waste including cheese whey, waste cooking oil, coffee waste, and animal fat is an innovative practice for food waste management. This approach not only mitigates environmental impacts but also contributes to sustainable development and economic growth. Downstream processing techniques for PHAs are discussed, highlighting their role in obtaining high-quality materials. The study also addresses sustainability considerations, emphasizing biodegradability and recycling, while acknowledging the challenges associated with this path. [ABSTRACT FROM AUTHOR]

• Developed GHG emission models for incineration and landfilling. • Analyzed influencing factors of GHGs from MSW from space-time dimension. • Analyzed GHG emission pattern of legacy MSW. • Forecasted GHG emissions from MSW before 2030. The municipal solid waste (MSW) management is significantly contributing to global greenhouse gas (GHG) emissions. Analyzing the emission pattern of GHGs from MSW is essential for formulating appropriate carbon mitigation policies. Based on IPCC Models, GHG emissions from MSW were calculated in Chinese provinces from 2004 to 2021 by landfilling and incineration operations, separately. Landfilling and incineration generated approximately 1271 MtCO 2 -eq and 198 MtCO 2 -eq from 2004 to 2021, respectively. GHG emissions from landfilling increased from 2004 to 2020 and declined in 2021, while GHG emissions from incineration demonstrated an increasing trend with three distinct growth stages. A panel regression model was then employed to identify the key factors influencing GHG emissions. GDP and population are positively related to GHG emissions from landfills, while PCCE is negatively related to GHG emissions from landfills. GDP and PCCE have a positive impact on GHG emissions from incineration, while population showed no significant impact. Multi-expression programming was used to develop an explicit model, forecasting GHG emissions from MSW by 2030. From 2022 to 2024, GHG emissions from landfills will quickly decrease, while GHG emissions from incineration will rapidly increase. Subsequently, the GHG emission rate of incineration will slow down, and GHGs from landfilling will slowly decrease due to no MSW for landfill disposal. The methods and results provide insightful information for policy-makers and waste management sector. [ABSTRACT FROM AUTHOR]

• Waste coffee pods (CP) were treated using a two-stage pyrolysis process. • A microwave-assisted pyrolysis process was employed for treating waste CP. • Catalytic reforming of evolved gas yielded 76 % (by volume) hydrogen at 900 °C. • Microwave and catalysis-assisted pyrolysis process can be a solution to upcycling. Plastic waste poses a critical environmental challenge for the world. The proliferation of waste plastic coffee pods exacerbates this issue. Traditional disposal methods such as incineration and landfills are environmentally unfriendly, necessitating the exploration of alternative management strategies. One promising avenue is the pyrolysis in-line reforming process, which converts plastic waste into hydrogen. However, traditional pyrolysis methods are costly due to inefficiencies and heat losses. To address this, for the first time, our study investigates the use of microwave to enhance the pyrolysis process. We explored microwave pyrolysis for polypropylene (PP), high-density polypropylene (HDPE), and waste coffee pods, with the latter primarily comprising polypropylene. Additionally, catalytic ex-situ pyrolysis of coffee pod pyrolysis over a nickel-based catalyst was investigated to convert the evolved gas into hydrogen. The single-stage microwave pyrolysis results revealed the highest gas yield at 500 °C for HDPE, and 41 % and 58 % (by mass) for waste coffee pods and polypropylene at 700 °C, respectively. Polypropylene exhibited the highest gaseous yield, suggesting its readiness for pyrolytic degradation. Waste coffee pods uniquely produced carbon dioxide and carbon monoxide gases because of the oxygen present in their structure. Catalytic reforming of evolved gas from waste coffee pods using a 5 % nickel loaded activated carbon catalyst, yielded 76 % (by volume) hydrogen at 900 °C. These observed results were supported by elemental balance analysis. These findings highlight that two-stage microwave and catalysis assisted pyrolysis could be a promising method for the efficient management of waste coffee pods, particularly for producing clean energy. [ABSTRACT FROM AUTHOR]

• Carbon footprint was used to evaluate the effect of source classification. • Unit carbon emission decreased to 0.14 t CO 2 -eq/t MSW after source classification. • The MSW management system is a carbon sink due to energy and material recovery. • Transportation contributes little to the total carbon emissions of the whole system. • Landfill gas utilization and plastic recycling were the two determining factors. Municipal solid waste (MSW) management is a critical concern in megacities that depend heavily on external material and energy inputs but lack space for waste disposal. MSW treatment is a significant contributor to carbon emissions. The implementation of source classification improved the overall MSW management system and enhanced resource recovery from MSW. However, the precise contribution of source classification to carbon emissions reduction remains unclear. This study aimed to analyze the carbon emissions evolution in the MSW management of Shenzhen, a prototypical megacity in China, using data from 2006 to 2020 and employing carbon footprint assessment methodologies. The results demonstrated that source classification reduced the carbon emissions from 0.19–0.25 to 0.14–0.18 t CO 2 -eq/t MSW when considering the contribution of the urban environmental sanitation management department. The entire MSW management system becomes a carbon sink when considering recyclables collected by commercial enterprises. Although the source classification complicated the collection and transportation of MSW, the carbon offset effect of recycling food waste and recyclables was more significant than that of carbon emissions from collection and transport. Moreover, the landfill gas recovery rate critically influenced the carbon emissions of landfill-based MSW management systems. In contrast, the recovery of plastics was crucial for determining carbon emissions from incineration-based MSW management systems. [ABSTRACT FROM AUTHOR]

Syngas (CO + H 2) production through biomass gasification offers a promising and sustainable alternative to conventional fuels. This study investigates the co-gasification of palm oil decanter cake (PODC) and Alum Sludge (AS), utilizing response surface methodology (RSM) and artificial neural network (ANN) techniques to optimize and predict syngas production. Conducted in a fixed bed horizontal reactor, the experiment investigates temperature, airflow rate, and particle size as input parameters. Results revealed that optimal condition of 900 °C temperature, 10 mL/min airflow rate, and 2 mm particle size yielded the highest syngas production at 39.48 vol%. The RSM showed an R2 value of 0.9896, whereas ANN network revealed an overall R2 value of 0.971. Both models demonstrated strong alignment with experimental data and the modelled equation. This research demonstrates the effective use of statistical modelling to enhance the efficiency and effectiveness of syngas production, thereby fostering advancements in sustainable energy production. [Display omitted] • PODC and AS co-gasification was carried out in fixed bed horizontal tube furnace reactor. • RSM and ANN were applied for optimization and prediction of syngas production. • At optimal condition of 900 °C, 10 mL/min, and 2 mm, 39.48 vol% syngas was produced. • RSM and ANN model prediction accuracy were 98.96% and 97.1%, respectively. • Both RSM and ANN satisfactory validate and predict the response. [ABSTRACT FROM AUTHOR]

[Display omitted] • Larvae of Hermetia illucens regularly develop on PVC-MPs-supplemented diet. • PVC-MPs are ingested by the larvae and reduced in their size. • Midgut morphology is not affected by PVC-MPs in the larval diet. • PVC-MPs in the larval diet do not affect microbial alpha- and beta-diversity. • PVC-MPs selectively affect the abundances of gut bacterial and fungal taxa. In a world with a population exceeding 8 billion people and continuing to grow, pollution from food and plastic waste is causing long-term issues in ecosystems. Potential solutions may be found by exploiting insect-based bioconversion. In this context, we investigated the impact of polyvinyl chloride microparticles (PVC-MPs) on the development of Hermetia illucens (black soldier fly; BSF) and its midgut bacterial and fungal microbiota. The impact of PVC-MPs was evaluated feeding BSF larvae with a PVC-MPs-supplemented diet. The larvae exposed to different PVC-MPs concentrations (2.5%, 5%, 10% and 20% w/w) developed into adults with no significant increase in pupal mortality. Faster development and smaller pupae were observed when 20% PVC-MPs was provided. The BSF larvae ingest PVC-MPs, resulting in a reduction in MPs size. Larvae exposed to PVC-MPs did not exhibit differences in gut morphology. Regarding the impact of PVC-MPs on the structure of both bacterial and fungal communities, the overall alpha- and beta-diversity did not exhibit significant changes. However, the presence of PVC-MPs significantly affected the relative abundances of Enterobacteriaceae and Paenibacillaceae among the bacteria and of Dipodascaceae and Plectospharellaceae among the fungi (including yeast and filamentous life forms), suggesting that PVC-MP contamination has a taxa-dependent impact. These results indicate that BSF larvae can tolerate PVC-MPs in their diet, supporting the potential use of these insects in organic waste management, even in the presence of high levels of PVC-MP contamination. [ABSTRACT FROM AUTHOR]

• A microwave-assisted protocol towards biofuel precursor furfural (FF) was implemented. • Namely almond hull (AH), olive stone (OS), and wine-derived by-products were evaluated. • Mild conditions (150 °C, 10–20 min) and green strategies (AlCl 3 ·6H 2 O) were applied. • Noted molar yield (38–42 %) and selectivity (50–60 %) were achieved from AH and OS. • Sustainable waste management and biorefinery approaches were assessed. This work outlines the first microwave (MW)-assisted protocol for the production of biofuel precursor furfural (FF) from the raw agricultural waste almond hull (AH), olive stone (OS), and the winemaking-derived grape stalk (GS), grape marc (GM) and exhausted grape marc (EGM) through a one-pot synthesis process. To enhance the overall yield, a catalytic process was firstly developed from xylose, major constituent of hemicellulose present in lignocellulosic biomass. This method afforded FF with 100 % selectivity, yielding over 85 % in isolated product when using H 2 SO 4 , as opposed to a 37 % yield with AlCl 3 ·6H 2 O, at 150 °C in only 10 min. For both catalysts, the developed methodology was further validated, proving adaptable and efficient in producing the targeted FF from the aforementioned lignocellulosic raw materials. More specifically, the employment of AlCl 3 ·6H 2 O resulted in the highest selectivity (up to 89 % from GM) and FF yield (42 % and 39 % molar from OS and AH, respectively), maintaining notable selectivity for the latter (61 and 48 % from AH and OS). At this regard, and considering the environmental factor of sustainability, it is important to point out the role of AlCl 3 ·6H 2 O in contrast to H 2 SO 4 , thus mitigating detrimental substances. This study provides an important management of agricultural waste through sustainable practises for the development of potential bio-based chemicals, aligning with Green Chemistry and process intensification principles. [ABSTRACT FROM AUTHOR]

• Estimates of modeled CH 4 emission (E) data for 1,325 U.S. landfills were reviewed. • Operators use two methods to estimate E from landfills with a gas collection system. • First-order decay (FOD) method shows increasing emissions. • Collection efficiency assumption method shows decreasing emissions. • FOD method shows some agreement to remotely sensed national estimates. As part of its commitment to the United Nations Framework Convention on Climate Change, the U.S. annually develops a national estimate of methane emissions from municipal solid waste (MSW) landfills by aggregating activity data from each facility. Since 2010, the U.S. has reported a 20 % decrease in MSW landfill emissions despite a 21 % increase in tons disposed. Operator-submitted data were investigated to understand the causes of this decline. In the U.S., operators of landfills with a gas collection and control system (GCCS) calculate their facility's emissions via two separate approaches – (1) first-order decay (FOD) and (2) collection efficiency assumption (CEA) − and select either result to feed into the annual inventory. The FOD model predicts methane generation proportional to waste disposal and that approach calculated a 19 % increase in total methane generated from 2010 to 2022, whereas generation via the CEA approach decreased by 8.9 %. The amount of measured methane collected has increased 7.5 % for the same years. Discrepancies between the two models' generated methane, assumed gas collection efficiencies, and oxidized methane compound into substantive differences in national estimates. Operators more frequently select the CEA method, which results in decreased national estimates. If only the FOD method was used, U.S. MSW landfill emissions would be 1.3-1.7 times greater than current estimates which is similar to recent extrapolations from remote sensing campaigns in the U.S. Both models contain parameters with large inherent uncertainty. Without measurement methods that continuously quantify both point-source and diffuse emissions, an assessment of either equation's accuracy cannot be made. [ABSTRACT FROM AUTHOR]

The gamma shielding parameters of an admixture of waste borosilicate glass (BS) and geopolymer (GP) made from activated metakaolin are presented in the present study. The influence of the BS quantity on the density and different gamma shielding quantities is investigated over a wide gamma energy range. Four batches of the G-BS composite were prepared using the solid-state diffusion method, containing 0 (G), 10 % (G-10BS), 20 % (G-20BS), and 30 % (G-30BS) by weight of BS, respectively. The chemical compositions of the G-xBS samples were determined through X-ray fluorescence spectrometry. In addition, the density of the BS-doped geopolymers was determined using the liquid displacement method using deionized water as the displacement fluid. The theoretical determination of estimating shielding parameters began by estimating the mass (μ ρ) and linear (μ) attenuation coefficients of the geopolymers for photon energies in the range of 15 keV to 15 MeV using the XCOM data library. The B and Si content and density of the geopolymer samples increased as the BS weight proportion increased in the geopolymer. The values of the attenuation coefficients (ACs) decreased with energy. For μ, the decrease was from 9.1533 to 0.0355 cm−1, 6.7486 to 0.0374 cm−1, 10.2964 to 0.0396 cm−1, and 10.7722 to 0.0414 cm−1, while for μ ρ , it was 5.3217 to 0.0206 cm2 g-1, 5.3860 to 0.0206 cm2 g-1, 5.3627 to 0.0206 cm2 g-1, and 5.3594 to 0.0206 cm2 g-1, for G, G-10BS, G-20BS, and G-30BS, respectively. There are no significant differences between the photon energy absorption capacity of the geopolymers, especially at energies greater than 1 MeV. The photon buildup factors of the G-xBS samples have very close relative values with no clear order. The introduction of waste borosilicate glass is therefore a way of improving the photon attenuation capacity of geopolymer and, therefore, the potential of shielding applications of geopolymer-based concrete. [ABSTRACT FROM AUTHOR]

In this paper, we propose two bilevel models to cope with problems concerning waste management. The first formulation stems from a multi-objective version of the problem present in the literature, while the second one improves upon the first by taking into account a theoretical result associated with the first formulation. For both models, we provide the optimistic and the pessimistic versions. We validate these formulations in a case study in the Pathum Thani province in Thailand. Moreover, we compare the results obtained by the bilevel formulation to those obtained by a multi-objective version of the problem. Finally, we provide our thoughts on future applications in this field. [ABSTRACT FROM AUTHOR]

The emergence of sustainability concepts within the energy sector has prompted a heightened interest in exploring alternative avenues to meet global energy demands. The embracement and integration of SDG 7 as a pivotal objective for the future energy landscape have spurred the development of comprehensive frameworks aimed at embedding sustainability principles within the energy sector's core fabric. In this pursuit of sustainable energy solutions, bio-hydrogen has emerged as a promising waste-to-energy concept, serving as a bridge between SDG 6 and SDG 7, thereby addressing both waste management and energy production imperatives. Among the diverse array of methods, biomass fermentation stands out as an effective approach, wherein waste streams derived from industrial and municipal sources can be utilized as feedstock for biohydrogen fermentation. While this approach exemplifies a step towards a circular economy, the treatment of the fermentation broth poses significant challenges, primarily due to the generation of bio-hazardous and toxic effluents. The fermentation broth is replete with microbial species, metabolites, organic compounds, and inorganic residues, rendering direct discharge untenable due to the adverse environmental and ecological ramifications. Consequently, the treatment and management of fermentation effluent have emerged as formidable techno-economic barriers inhibiting the industrial-scale upscaling of biohydrogen production processes, prompting widespread attention within the research community. This review aims to elucidate the various practices employed in post-fermentation broth treatment and management, shedding light on current methodologies, and highlighting areas for future advancement, particularly towards achieving zero liquid discharge from hydrogen fermentation processes. • Scale up of biohydrogen as clean and green energy source hindered by technical, economic and environmental factors. • Post-fermentation broth from biohydrogen production poses ecological ramifications. • Manging the broth while adding value to waste need of the hour. • Pathways for simultaneous effluent management and adding economic value to the waste overviewed. [ABSTRACT FROM AUTHOR]

In the study, the solid solubility limits of Cr3+ in the CaAl 12-x Cr x O 19 phase and leachability of any Cr6+ safety were investigated. Analytical tools and leaching experiments were used to investigate the Al3+ substitution in hibonite (CaAl 12 O 19) structure by Cr3+. The results showed that at Al:Cr=9:3, all the generated phases were chrome-hibonite (Ca 1.06 Cr 2.87 Al 9.07 O 18.99) and were also supported by the XPS and Cr6+ leaching experiments results. However, when proportion of Cr in system increases to Al:Cr=7:5, the primary phases are Ca 1.09 Cr 3.92 Al 8.01 O 18.98 and alumina-chrome solid solution (Al 0.77 Cr 1.22 O 3) along with a small amount of wuboraite solid-solution (CaAl 2±x Cr 2±x O 7 , a Cr3+ phase) and chrome-hauyne (Ca 4 Al 6 CrO 16 , a Cr6+ phase). At Al:Cr=7:5, distilled water and 0.1 mol/L HCl leach around 1.9 mg/L Cr6+, but HCl showed relatively faster leaching of Cr6+ than water and below the Chinese national standard of waste disposal of 3 mg/L. The maximum solid-solubility limit of Cr3+ in CaAl 12-x Cr x O 19 could be considered as x =3.9. [ABSTRACT FROM AUTHOR]

• The impact of managing textile waste generated in the EU was 7 Mt CO 2 eq. in 2019. • Policy interventions can redirect waste flows in and outside of the EU. • Interventions in waste management can reduce sector-wide impacts by up to 18%. • Investments required at present are 7–33 billion EUR compared to the status quo. • Without addressing production & consumption, sustainability goals are hard to meet. With increasing textile consumption and limited sorting and recycling capacities, the EU faces major challenges in terms of managing its textile waste. This study investigates the environmental and socio-economic impacts of explorative policy scenarios for a more sustainable textile waste management system in Europe. These scenarios differ substantially in the amounts of textile waste generated and separately collected, closed-loop recycling capacities and textile waste exports. Our results show that sustainable textile waste management remains highly relevant for the sector. Still, without addressing in parallel prevention of textile waste generation via production and consumption patterns, a climate-neutral and circular textiles sector will be hard to achieve. Interventions in the waste management of textiles could reduce global warming impacts by up to 22.3 Mt CO 2 per year, which translates to an 18% sector-wide impact by 2035. Depending on the intervention(s), the estimated required investment at present amounts to between 7 and 33 billion EUR. The study provides a valuable starting point for evidence-based decisions on future textile policymaking in Europe. [ABSTRACT FROM AUTHOR]

• Hazardous HCW represents a 26.5 % of waste generated in dental clinics in this study. • Biological waste was the most generated hazardous waste group. • Incineration emerges as the primary treatment method for hazardous HCW. • Non-hazardous waste, destined for landfills, exhibits low recycling rates (2.4 %). • Challenges include mainly inadequate segregation practices and limited recycling. Healthcare waste management is a critical aspect of public health and environmental protection, particularly in establishments such as dental clinics. This study examined the dental clinic waste (DCW) management processes in clinics within the city of Belo Horizonte, Brazil. Utilizing data from Healthcare Waste Management Plans (HCWMP) provided by the Urban Cleaning Superintendence, the study investigated waste generation, segregation, storage, collection, treatment, and final disposal practices. The results revealed that hazardous DCW represented a significant portion (26.5 %) of waste generated in dental clinics, exceeding the World Health Organization's recommended threshold. Biological waste (22.9 %), mainly consisting of cotton, gauze, and gloves contaminated with blood or body fluids, was the most generated hazardous waste group, followed by chemical (2.2 %) and sharps waste (1.3 %). Incineration was the predominant treatment method for hazardous DCW, raising concerns about environmental impacts and greenhouse gas emissions. Non-hazardous waste, primarily destined for landfills, had limited recycling rates (2.4 %), emphasizing the need for improved waste management strategies to minimize environmental impacts and increase circular economy. Challenges in DCW management included inadequate segregation practices, limited recycling initiatives, and incomplete HCWMPs lacking descriptions of waste management beyond establishment boundaries. Addressing these challenges requires comprehensive training programs, strengthened regulations, and increased environmental awareness among healthcare professionals. In conclusion, improving DCW management in dental clinics is crucial for mitigating occupational and environmental risks. Collective efforts are needed to enhance waste segregation, promote recycling, and ensure compliance with regulations, ultimately safeguarding public health and the environment. [ABSTRACT FROM AUTHOR]

• Case study feasibility of real-time computer vision-based scrap metal separation. • Analysis of neural network architectures for recognition of forbidden scrap. • Proposal of a neural classifier analyzing a non-standardized stream of metal scrap. • Dataset augmentation for improved model robustness of a neural classifier. • Eliminating human in the detection of prohibited objects in copper-based scrap. Highly efficient industrial sorting lines require fast and reliable classification methods. Various types of sensors are used to measure the features of an object to determine which output class it belongs to. One technique involves the use of an RGB camera and a machine learning classifier. The paper is focused on protecting the sorting process against prohibited and dangerous items potentially present in the sorted material that pose a threat to the sorting process or the subsequent metallurgical process. To achieve this, a convolutional neural network classifier was applied under real-life conditions to detect forbidden elements in copper-based metal scrap. A laboratory stand simulating the working conditions in a high-speed scrap sorting line was prepared. Using this custom stand, training and test sets for machine learning were gathered and labeled. An image preprocessing algorithm was designed to increase the robustness of the resulting forbidden element detector system. The performance of multiple neural network architectures and data set augmentations was analyzed. The highest accuracy of 98.03% and F1-score of 97.16% were achieved with a DenseNet-based classifier. The results of this paper show the feasibility of using the presented solution on a high-speed industrial line. [ABSTRACT FROM AUTHOR]

[Display omitted] • Controlled irrigation reduced net global warming potential (net GWP) by 16–220%. • Hydrochar addition decreased greenhouse gas emission by 10–41% compared to straw addition. • Hydrochar and straw addition increased net ecosystem carbon budget (NECB) by 21–34%. • Hydrochar + controlled irrigation reduced greenhouse gas emission while increased NECB. Hydrochar is proposed as a climate-friendly organic fertilizer, but its potential impact on greenhouse gas (GHG) emissions in paddy cultivation is not fully understood. This two-year study compared the impact of exogenous organic carbon (EOC) application (rice straw and hydrochar) on GHG emissions, the net ecosystem carbon budget (NECB), net global warming potential (net GWP), and GHG emission intensity (GHGI) in a rice pot experiment using either flooding irrigation (FI) or controlled irrigation (CI). Compared with FI, CI increased ecosystem respiration by 23 – 44 % and N 2 O emissions by 85 – 137 % but decreased CH 4 emissions by 30 – 58 % (p < 0.05). Since CH 4 contributed more to net GWP than N 2 O, CI reduced net GWP by 16 – 220 %. EOC amendment increased crop yield by 5 – 9 % (p < 0.05). Compared with CK, hydrochar application increased initial GHG emission, net GWP and GHGI in the first year, while in the second year, there was no significant difference in net GWP and GHGI between CI–hydrochar and CK. Compared with straw addition, hydrochar amendment reduced net GWP and GHGI by 20 – 66 % and 21 – 66 %; and exhibited a lower net CO 2 emission when considering the energy input during the hydrochar production. These findings suggest that integrated CI-hydrochar practices would be a sustainable and eco-friendly way for organic waste management in rice production as it holds potential to enhance the NECB and SOC sequestration of rice production, while also offsetting the extra carbon emissions from organic inputs. [ABSTRACT FROM AUTHOR]

• The paper explores the role of AI in sorting solid waste in service building. • The developed virtual assistant supports verbal and visual input from users. • The developed virtual assistant provides immediate directions based on policies. • The developed virtual assistant permits facility manger to track sorting behaviour. • Using a virtual assistant can increase occupants engagement in waste sorting plans. 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. [ABSTRACT FROM AUTHOR]

Food waste raises severe concerns all around the globe. Thus, several researchers employed various food waste additives in the earthen matrix to improve their performance, decrease energy consumption, and efficient waste management. Therefore, this study evaluates the Tea Waste (T.W.) additive in producing unfired clay brick by adding different ratios in the brick clay mixtures 2.5 %, 5 %, 7.5 %, and 10 % of the weight. Samples were prepared and dried under natural laboratory conditions at 20o C for 7 days until weight and shrinkage stabilization, followed by oven-dried for 48 h at 60 oC. Several tests were performed to examine the physical and mechanical characteristics of the samples, including flexural strength, density, compressive strength, linear shrinkage, capillary water absorption, thermal conductivity, and the U.P.V. The results demonstrated that porosity and shrinkage slightly increased. While density, flexural strength, and compressive strength values decrease. In addition, the thermal conductivity increased depending on the T.W. content. In addition, samples containing 2.5 % and 5 % of T.W. give better compressive strength results above 3.5 MPa, which is the least limit required according to the Indian standards IS 1077, while T.W. additive of 7.5 % and 10 % did not fulfill the standard's strength requirement and therefore could be used for isolation only due to the increased amount of porosity that improves the thermal conductivity. The results indicated that samples with suitable mechanical and physical properties could achieve a suitable amount of T.W. it is recomenned that the porous structure of the clay brick body impacted the clay brick's properties and can be an effective alternative to porosity makers for lightweight insulating brick production. [ABSTRACT FROM AUTHOR]

This paper presents a detailed review of the plasma gasification process for waste disposal. Due to Shifting economies and consumerism culture, ample change can be seen across the globe in the form of rapid industrialisation and burgeoning urbanisation, which results in a massive increase in waste generation. Plasma gasification technology is an emerging solution for processing a wide range of waste making it a highly sustainable, efficient, and ecologically sound process. This literature review discusses the feasibility of the plasma gasification method and its superiority over other conventional waste disposal techniques. A comprehensive analysis of different methods of plasma generation for gasification is done in this literature review. The review paper presents a detailed coverup of the entire process of plasma gasification and post-processes. The article discusses the notable advancement, current scenario, and possibilities in plasma gasification methodology in terms of the design of plasma torch, modelling of gasifiers, generation of syngas, and power production. It provides an overview of advanced simulation tools helpful in the analysis of the Waste-to-Energy (WtE) process. This literature review aims to provide an overview of the recent advances in plasma gasification, highlighting the technical aspects, environmental benefits, and economic viability of the technology. It also reviews the latest research and developments in plasma gasification and discusses the challenges and limitations of the technology, as well as the future prospects and potential applications. • Plasma gasification methodology for waste treatment is discussed in detail. • Prominent thermal and non-thermal practices are discussed and compared in this literature review. • Selective use of plasma gas for enhanced efficiency and optimised gas yield/composition. • Hybrid systems offer versatility in processing diverse feedstocks and can achieve higher energy efficiencies. • Plasma-catalysis approach with NTP shows desirable syngas yield. [ABSTRACT FROM AUTHOR]

Higher cost of production and functioning efficiency are the two most important aspects of cellulolytic enzymes, as they directly affect the bioconversion of cellulosic waste into fermentable sugars. Thus, the current study aims to investigate the production of cellulolytic enzymes from low-cost waste biomass for use in the sustainable hydrolysis of biomass to yield fermentable sugars. Since coconut waste is a major contributor to biodegradable waste, two different parts of coconut, including the hard shell of coconut (CS) and the fibers of the shell (FS), have been used for enzyme production as feedstock. Further, enzyme production has been carried out on co-fermentative and acid-pretreated coconut substrates (CS and FS) at different quantities using mixed bacterial cultures. Following this, a crude enzyme with a maximum 20 U/gds FPA, 62 U/gds BGL, and 167 U/gds EG has been produced by mixed Bacillus cultures under co-fermentation of 0.5 % acid-pretreated CS and FS substrates at a quantity of 5:5 (g:g) at 35 °C and pH 5.0. The crude enzyme showed its thermal stability for 16 h at 50 °C and released ~34 g/L of sugars from the hydrolysis of untreated FS biomass in 24 h. This work may have significant applications in the area of biomass-based biorefining as well as waste management. [ABSTRACT FROM AUTHOR]

Poor clinical waste management and its effect on the environment is an increasingly recognised concern for global healthcare systems. Approximately two thirds of waste produced in healthcare is from the operating theatre. In the Republic of Ireland, an estimated 580,977 tonnes of hazardous waste was produced in 2019. The cost of incineration of this hazardous waste is approximately €2,125 per tonne and €935 per tonne for sterilisation. Pollution from incineration is substantial and harmful. A literature review was performed on the topic of hospital waste management, specifically looking at the Republic of Ireland. A comparison could then be drawn between Ireland, Europe and the United States of America. Observation of our current operating theatre environment and practices were carried out. An increased focus towards sustainability and reusable equipment means that there is potentially a decreased amount of waste for disposal, but an increase in the process of sterilisation. Approximately 66% of healthcare related waste is inappropriately contaminated, meaning that significant savings are possible if correct segregation and recycling were to occur. An increase in the amount of bins, identification labels above bins and education of staff results in an increased likelihood of successful segregation of waste. Clear and concise hospital guidelines of what is considered hazardous versus non-hazardous waste will decrease the amount of inappropriately disposed items. • Operating theatres account for approximately 70% of healthcare waste. • Increased use of reusable materials and equipment in the operating theatre. • The incineration cost of hazardous waste is approximately €2,125 per tonne. • Sterilisation cost of hazardous material is approximately €935 per tonne. • Increased labels and education of staff can reduce inappropriate waste disposal. [ABSTRACT FROM AUTHOR]

As hospitals strive to reduce their environmental footprint, there is an ongoing debate over the environmental implications of reusable versus disposable linens in operating rooms (ORs). This research aimed to compare the environmental impact of reusable versus single-use OR bed covers and lift sheets using life cycle assessment (LCA) methodology. LCA is an established tool with rigorous methodology that uses science-based processes to measure environmental impact. This study compared the impacts of three independent system scenarios at a single large academic hospital: reusable bed covers with 50 laundry cycles and subsequent landfill disposal (System 1), single-use bed covers with waste landfill disposal (System 2), and single-use bed covers with waste disposal using incineration (System 3). The total carbon footprint of System 1 for 50 uses was 19.83 ​kg carbon dioxide equivalents (CO 2 -eq). System 2 generated 64.99 ​kg CO 2 -eq. For System 3, the total carbon footprint was 108.98 ​kg CO 2 -eq. The raw material extraction for all the material to produce an equivalent 50 single-use OR bed cover kits was tenfold more carbon-intensive than the reusable bed cover. Laundering one reusable OR bed cover 50 times was more carbon intensive (12.12 ​kg CO2-eq) than landfill disposal of 50 single-use OR bed covers (2.52 ​kg CO2-eq). Our analysis demonstrates that one reusable fabric-based OR bed cover laundered 50 times, despite the carbon and water-intensive laundering process, exhibits a markedly lower carbon footprint than its single-use counterparts. The net difference is 45.16 ​kg CO2-eq, equivalent to driving 115 miles in an average gasoline-powered passenger vehicle. This stark contrast underscores the efficacy of adopting reusable solutions to mitigate environmental impact within healthcare facilities. • Life cycle assessments are a data-driven approach to facilitate healthcare sustainability • A reusable bed cover laundered 50x has a lower carbon footprint than single-use ones • Surgical equipment choices by surgeons can affect the environment [ABSTRACT FROM AUTHOR]

Decarbonizing the building sector to achieve sustainable development goals (SDGs) is a complex issue that poses significant challenges to the scientific community. In this context, the current paper aims to assess the viability of employing incinerated by-products as a sustainable mineral resource to produce sustainable geopolymers. To this end, the study focuses on the formulation of geopolymer binders using fly ash with various proportions (ranging from 0 % to 50 %) of metakaolin (MK), investigating their physico-mechanical, microstructural analysis as well as their sealing capacity. The results indicate that incorporating 30 % MK not only preserves good workability but also significantly improves mechanical strength, ensuring long-term durability by increasing bulk density and concurrently reducing water absorption and harmful porosity. Moreover, the results of the Toxicity Characteristic Leaching Procedure (TCLP) demonstrated that the released contaminants remained within the regulatory limits established by the USEPA. The geopolymer binder developed exhibited a significant reduction of 77.23 % and 57.92 % in terms of carbon dioxide equivalent (CO 2 -e) emissions and energy demand compared to conventional cement. This study introduces a novel approach to promoting a circular economy within the building sector. [Display omitted] [ABSTRACT FROM AUTHOR]

Batteries are one of many types of solid waste. Once utilized, they are considered and categorized as 'hazardous waste' since they can cause major problems if unlawfully disposed of. The synthesis of ZnO nanoparticles using eco-friendly methods and their application in photocatalysis is crucial due to the environmental and economic benefits of recycling Zn plates from waste batteries. This innovative approach not only offers a sustainable solution for waste management but also presents an opportunity to harness the photocatalytic properties of ZnO nanoparticles for various environmental remediation applications, thereby contributing to the advancement of green nanotechnology and sustainable development. This study aims to address environmental concerns associated with battery waste and water pollution by proposing a sustainable and innovative approach. The focus is on recycling zinc plates from discarded batteries and synthesizing zinc oxide (ZnO) nanoparticles using eco-friendly methods. In this study, ZnO nanoparticles were synthesized on the Zn plates isolated from waste batteries by reacting the plates in the presence of hydrogen peroxide. SEM and EDS were used to characterize the final ZnO-coated Zn plate. The presence of ZnO nanoparticles with small spherical forms and modest diameter variation on the Zn plate was confirmed by SEM data. Furthermore, the photocatalytic treatment of azo dyes with the obtained ZnO-coated Zn plates was examined. The investigation yielded degradation rates of 72.7% and 57.4% for Remazol Brillant Blue R (RBBR) and Basic Red 18 (BR 18), respectively. Results demonstrate the potential of the ZnO-coated Zn plates as effective photocatalysts, highlighting their role in promoting sustainability in both waste management and water treatment. This work contributes to advancing eco-friendly technologies and underscores the importance of sustainable practices in addressing contemporary environmental challenges. [Display omitted] • Zn plates were recycled from waste batteries and utilized in water treatment. • ZnO nanoparticles were synthesized on the surface of Zn plates using eco-friendly methods. • The photocatalytical activity of nano ZnO-coated plates was excellent. • The catalyst can be easily separated from the system after the procedure. • RBBR and BR 18 dyes were degraded by 72.7% and 57.4%, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • Large datasets of U and UP are constructed with 1526 and 743 fuel samples. • The effect of C, H, and O atomic ratios on HHV is investigated by ternary plots. • HHV of any type of waste and fuel is estimated by artificial neural networks. • Hyperparameter optimization is carried out to obtain best performing ANN models. • Ultimate analysis data is observed to be sufficient for HHV estimation of fuels. 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 R2 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. [ABSTRACT FROM AUTHOR]

[Display omitted] • A broad variety of radionuclides and elements were determined in SSA, APC and DFB. • Mobility of wide spectrum of elements in studied waste was examined. • Relatively high activity of 226Ra in SSA and DFB samples was observed. • The content of majority of elements in samples decrease in samples: SSA > DFB > APC. • High mobility of metalloids and low mobility of metals in SSA and DFB was observed. The research was aimed at providing new knowledge in the field of chemical characteristics of solid waste generated in the process of combustion of sewage sludge in fluidized bed furnaces. The research material consisted of disposed fluidized beds (DFB), sewage sludge ash (SSA) and air pollution control residues (APC) from three Polish installations for the thermal treatment of sewage sludge. Natural radionuclides as well as anthropogenic isotope 137Cs were determined in the tested materials and the migration of a wide spectrum of trace elements to various waste fractions generated in the process of sewage sludge combustion was examined. It was observed that both radioisotopes and most of the trace elements determined accumulate in SSA and DFB, while the APC fraction contains a much smaller amount of them. The exceptions are mercury and selenium, whose volatile compounds migrate to the exhaust gas dedusting system and accumulate in the APC fraction (up to 40 mg/kg and 13 mg/kg, respectively). A potential threat from the 226Ra isotope in SSA is identified in the context of the management of this waste in the production of building materials because the typical activity of 226Ra in SSA collected from areas with very low Ra content in natural environment exceeds 1.5–6 times the activity of this isotope in conventional cement mixtures. When managing SSA and DFB, special attention should be paid to the content of metalloids such as As, B and Se, due to the high content of mobile forms of these elements in the mentioned materials. [ABSTRACT FROM AUTHOR]

• Analysis of the importance of the social impact of e-waste in African countries. • Presentation of the S-LCA methodology. • Presentation of the Social Hotspot Analysis of e-waste in Ghana and Nigeria. • Definition of a possible setoff indicators for assessing the Social impact of e-waste with site specific data. The transition towards a circular economy, which has emerged as a promising approach to achieving sustainable development and which involves the reuse of e-waste, may cause significant social impacts on vulnerable groups if it is not addressed in a proper manner. The European Union has established a clear circular economy plan with particular attention on e-waste treatment. However, a considerable amount of e-waste still ends up outside Europe, mainly in African Countries. Social Life Cycle Assessment (S-LCA) has been recognized as a valid methodology to assess the social impacts caused by products or services to stakeholders involved along the life cycle perspective. Most S-LCA studies are conducted in the formal sector; however, informal sectors constitute a crucial element of the economy in emerging and developing countries. In particular, formal waste management practices are complemented by the informal sector in Indonesia, African and Latin American countries. The informal sector represents an important support element. Few studies have been conducted on the social impacts of the e-waste sector and even fewer have been implemented following the guidelines of Social Life Cycle Assessment for Products and Organizations. However, we are still far from a complete overview of the social impacts in the e-waste sector, in particular for developing countries. Knowing that most e-waste through illegal exportation ends up in African countries, a social hotspot analysis has been conducted on the electronic sector in African countries, focusing on Nigeria and Ghana, which are the most affected. The study also identifies a set of indicators needed to assess the social performance of e-waste in Nigeria and Ghana. [ABSTRACT FROM AUTHOR]

• AI improves infectious waste management. • Ensemble model exceeds 97.81% accuracy. • Reinforcement learning optimizes classification. • Geometric augmentation boosts model robustness. • Study addresses urgent urban waste challenges. This research paper focuses on effective infectious municipal waste management in urban settings, highlighting a dearth of dedicated research in this domain. Unlike general or specific waste types, infectious waste poses distinct health and environmental risks. Leveraging advanced artificial intelligence techniques, we prioritize infectious waste categorization and optimization, integrating metaheuristics into optimization methods to create a robust dual-ensemble framework. Our model, the "Enhanced Artificial Intelligence for Infectious Municipal Waste Classification System," combines ensemble image segmentation methods and diverse convolutional neural network models. Innovative geometric image augmentation enhances model robustness, diversifies training data, and improves accuracy across waste types. A pivotal aspect is the integration of a reinforcement learning-differential evolution algorithm as a decision fusion strategy, optimizing classification by harmonizing outputs from ensemble methods and convolutional neural network models. Computational results, using a newly collected dataset, demonstrate our model's accuracy exceeding 96.54% while using the existing solid waste dataset we achieve the accuracy of 97.81%, outperforming advanced approaches by margins ranging from 2.02% to 8.80%. This research significantly advances sustainable waste management, showcasing artificial intelligence's transformative potential in addressing intricate waste challenges. It establishes a foundational framework prioritizing efficiency, effectiveness, and sustainability for future waste management solutions. Acknowledging the importance of diverse datasets, customization for urban contexts, and practical integration into existing infrastructures, our work contributes to the broader discourse on the role of artificial intelligence in evolving waste management practices. [ABSTRACT FROM AUTHOR]

• Excessive penalty rates may be crime-encouraging in illegal waste disposal. • Optimal sanctioning systems must necessarily account for corruption practices. • Experimental evidence shows that fines may feed corruption in waste disposal. Corruption is known to be one of the real life situations which may jeopardize the effectiveness of fines in deterring crime. We present a model of 'crime with corruption' by which both the dilution of crime deterrence due to corruption, as well as the possibility of crime encouraging fines, are formally highlighted. More importantly, by running an experiment on a subject pool of students for the case of illegal waste disposal, we provide experimental evidence on the validity of our theoretical predictions. We find that increasing fine rate may become crime encouraging, or at least ineffective, beyond a context-specific fine threshold. From a policy perspective, we suggest that the optimal design of a crime-deterring sanctioning system must simultaneously account for both corruption practices and anti-corruption policies. [ABSTRACT FROM AUTHOR]

Smouldering has recently been developed as a cost effective and energy efficient technology for challenging wastes. These systems are often used to eliminate environmental liabilities, and only minimal work has explored their use for generating useful by-products. This study addressed this research gap and demonstrated that applied smouldering systems can be tuned to favour hydrogen production. Calcium oxide and steam were added to the smouldering system, which completely treated woody biomass and coal tar, while producing hydrogen. The maximum hydrogen concentration achieved in the smouldering system was 33.7%, resulting in a net energy positive syngas. Results suggest that both heterogenous gasification and the water gas shift were key mechanisms behind hydrogen formation. These results indicate that smouldering systems can be used as a new method to sustainably produce hydrogen-rich syngas from challenging wastes. [Display omitted] • Experimental study produced up to 34% H 2 from smouldering combustion. • Experiments used different fuels, porous media, steam, and CaO amendments. • New methodology to drive net-energy-positive H 2 -rich syngas from smouldering. • Optimum steam/carbon ratio was found to be between 2 and 3 to maximize H 2 yield. • Heterogenous gasification and the water gas shift were key H 2 production mechanisms. [ABSTRACT FROM AUTHOR]

• A model is developed to assess the effectiveness of CDWM on a city scale. • Performance levels and weaknesses in CDWM practices of the GBA are identified. • Differences of CDWM across GBA cities are revealed through empirical study. The growing generation of construction and demolition waste (CDW) has emerged as a prominent challenge on global environmental agendas. However, the effectiveness of CDW management (CDWM) strategies varies among cities. Existing literature predominantly evaluates the effectiveness of CDWM at the project level, offering a localized perspective that fails to capture a city's comprehensive CDWM profile. This localized focus has certain limitations. To fill this gap in city-scale evaluations, this study introduces a novel model for assessing CDWM effectiveness at the municipal level. An empirical investigation was conducted across 11 cities within the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) to operationalize this model. The model defines five distinct levels of CDWM effectiveness. Findings indicate that Hong Kong consistently achieves the highest level (level I), while the majority of cities fall within levels III and IV. This pattern suggests that CDWM effectiveness in the GBA is moderately developed, with uneven progress in CDW management outcomes and supporting systems. Essentially, there is a lack of synchronous development of CDWM results and guarantee systems. The proposed evaluation model enriches existing CDWM research field and offers a framework that may inform future studies in other countries. [ABSTRACT FROM AUTHOR]

• This study proposes a model to consider quality degradation in glass recycling. • The model is based on technical quality substitutability and market applicability. • The model was applied to a case study on glass waste treatment. • Accounting for quality degradation, only 83% of cullet can replaces raw materials. • The decrease of recycling benefits was of 13–23% for the examined impact categories. The sustainability assessment of waste management systems requires tools capable of evaluating material quality degradation during recycling. Existing research has predominantly focused on the development of substitutability models for plastics, leaving a gap in addressing other materials like glass. Glass is commonly regarded as endlessly recyclable, even though its actual recyclability depends on several crucial factors, such as colour and pollutant contamination. Many Life Cycle Assessment (LCA) studies in this field assume a one-to-one substitution coefficient, neglecting material deterioration and inaccurately representing real-world scenarios. This study proposes and assesses a substitutability model for glass, aiming to measure the replacement extent between virgin materials and recycled crushed glass (cullet). The methodology is based on two key factors: technical quality substitutability, considering impurities and colour contaminations in cullet, and market applicability, accounting for market demand. Once formulated, the model was applied to a European case study on glass waste treatment. Two scenarios were considered: one assuming complete substitution between cullet and raw materials, the other incorporating quality degradation. Findings indicate that, accounting for quality degradation, only 83% of cullet effectively replaces raw materials, resulting in a decrease of the benefit associated with recycling of 13–23% for the different examined impact categories, compared to complete replacement assumption. This underscores the importance of considering quality deterioration in glass recycling impact assessments. [ABSTRACT FROM AUTHOR]

• Review of life cycle assessment papers on textile waste management and practices. • In integrated textile waste management systems, reuse should be prioritised. • Longer service life and good use phase practices give lower environmental impacts. • Many variables influence the impact assessment of textiles reuse and recycling. • Data about people attitude towards textiles circularity could support LCA studies. To understand which are the best strategies for textile waste management and to analyse the effects on the environment of applying circular economy practices to textile products, a review of 45 publications where life cycle assessment (LCA) is applied to these topics has been carried out. The separate collection of textiles, followed by reuse and recycling brings relevant environmental benefits, with impacts related to reuse resulting lower than those of recycling. At the opposite, when mixed municipal solid waste is addressed to energy recovery, the textile fraction is the second most impacting on climate change, right after plastics, while for landfill disposal impacts textiles directly follow the more biodegradable fractions. Textiles manufacturing using recycled fibres generally gives lower impacts than using virgin ones, with a few exceptions in some impact categories for cotton and polyester. The circular practices with the lowest impacts are those that ensure the extension of the textiles service life. Another aim of this review is to identify the main variables affecting the life cycle impact assessment (LCIA). These resulted to be the yield and material demand of recycling processes, the use phase variables, the assumptions on virgin production replaced by reuse or recycling, the substitution factor in reuse, and transportation data in business models based on sharing. Thus, in LCA modelling, great attention should be paid to these variables. Future research should address these aspects, to acquire more relevant data, based on industrial-scale processes and on people habits towards the circular economy strategies applied to textiles. [ABSTRACT FROM AUTHOR]

Addressing the critical issues of Electronic waste (E-waste) with its low recycling and environmental impacts, this study highlights the necessity for efficient waste management and energy recovery. Leveraging petroleum coke's rich carbon content, co-gasification presents a viable method to transform E-waste into syngas. Using response surface methodology (RSM), the research analyzes various E-waste and petroleum coke blends, focusing on how gasification temperatures and pressures affect cold gas efficiency (CGE). Results highlight that the 25% printed circuit board (PCB) socket blend achieves an optimal CGE of 66.03% at 1,171.27°C and 1.95 bar via RSM and attains 64.10% CGE at 1,150°C and 1 bar as per the equilibrium model, in contrast to the 75% blend's CGE of 49.96% at 1,256°C and 1.57 bar, and 47% at 1,250°C and 1 bar. These findings reveal significant optimization opportunities in co-gasification processes, providing key insights for efficient E-waste handling and syngas generation. [ABSTRACT FROM AUTHOR]

Disposal and harmless utilization of coal-based solid waste, industrial sludge, and other bulk industrial solid waste is a sustainable and economical approach. In this study, coal gangue and printing and dyeing sludge were recycled to reconstruct high-strength ceramsite using a simple and scalable method. The high silica and alumina contents in coal gangue provided a foundation for ceramsite preparation, and the iron oxide in the printing and dyeing sludge could reduce the sintering temperature. The optimal synthesis conditions were as follows: Coal gangue: printing and dyeing sludge = 40:60; sawdust content of 9mass%; sintering temperature of 1175 °C for 15 min; and preheating temperature of 400 °C for 10 min. The designed ceramsite exhibited high compressive strength of 27.26 MPa, low 1-h water absorption of 1.26%, and bulk and apparent densities of 998 and 1597 kg/m3, respectively; thus, it was categorized as high-strength ceramsite. In determining the modelling mechanism during the sintering process, the silicon and aluminum distributions on the ceramsite surface obtained under the optimal preparation conditions was highly consistent, forming a silicoaluminate that supported the ceramsite strength. Sawdust addition increased the pore structure of the ceramsite. The heavy metals contained in the raw materials were well-immobilized in the ceramsite, indicating that the prepared ceramsites were free from secondary contaminants. Use of bulk solid waste to prepare high-strength ceramsites is a feasible resourceful and harmless utilization method, which is of great significance for bulk solid waste disposal and reuse. [Display omitted] • Coal gangue and printing and dyeing sludge were synergistic disposed. • High-strength ceramsite with high performance was prepared. • Preparation conditions for the optimum performance of ceramsites were obtained. • High-strength ceramsite has minimal secondary pollution to the environment. [ABSTRACT FROM AUTHOR]

• Agent-based modelling is a powerful tool for evaluating the impact of the circular economy (CE). • Agent-based CE literature is fragmented and lacks a comprehensive framework. • Our systemic review finds three main themes in the literature. • We develop an integrated framework for agent-based model that complements general equilibrium models. • Our insights contribute to the theory and open future avenues of research. Circular Economy (CE) is a popular topic for governments and businesses around the world; yet, only a few comprehensive and economy-wide frameworks exist, and the consequences of the CE on economic systems stay unclear. With this systematic review, we put under scrutiny the existing contributions to Circular Economy (CE) that apply the Agent-based modelling methodology. There is an open gap in the CE literature regarding the use of ABM. The research question that guides this systematic review concerns the potential benefit of ABM for CE and how to use this methodology in the context of CE. We put in evidence three thematic areas, two agents and one process, namely producers , i.e. firms and industrial systems, consumers , i.e. households and waste disposal, and the diffusion of innovation. We infer that the former three thematic strands of literature can be further synthetized together to form a general model of the Circular Economy. This development is crucial to properly evaluate how the agent's heterogeneity affects the diffusion and the consequences of the adoption of CE practices on the economy. Research has widely applied ABM simulations to consider the impact of heterogeneity amongst individuals and their behavioural interactions on the evolution of complex systems, yet very little did it systematically about CE. Our results complement those of Computable General Equilibrium models. The review provides an interpretative framework, suggests valuable future research directions within the new comprehensive thematic area, and contributes to the theoretical and managerial discussion on agent-based modelling in the circular economy. [ABSTRACT FROM AUTHOR]

[Display omitted] • First study regarding MP pollution in plastic recycling facilities in Türkiye. • Plastic recycling facilities are discharging reaches up to 58,468 MP/L. • Low density and lower sized MPs can sink with the adsorbed pollution in washing unit. • OpenSpecy increased the hit qualities of polymers in identification of MPs. There is little knowledge about microplastic (MP) pollution in plastic recycling facility (PRF) wastewater. In this study, MPs in the wastewaters of four PRFs located in Türkiye were characterized for size, shape, color, and polymer types after sieving from 5,000 µm to the lowest 75 µm with seven sieves. The wet peroxide oxidation procedure was applied before attenuated total reflectance fourier transform infrared spectroscopy analysis for polymer identification. Polyethylene, and polypropylene were the dominant (75 % of total count) MP types within 22 polymer types. Average hit qualities of polymers increased from 69 % to above 84 % for the device software (OPUS) and open software (OpenSpecy). The abundance of MPs was determined as 53,987 MPs/L and 0.8 g MP/L for mixed PRFs 7,582 MPs/L and 4.6 g/L for the LDPE recycling facility, and 2,196 MPs/L and 0.06 g MPs/L for the granulation cooling water by count and weight, respectively. Small-sized MPs are found in the bottom sample much more than the surface and effluent samples in the washing tank. This indicated that MPs adsorbed the pollutants settled in the washing tank due to adsorbed pollution/biofilm. A maximum of 4.6 kg MP/ton of plastic recycled can be discharged as MPs that can be recovered. Considering the plastics recycling capacity, discharged MPs in these PRFs are possibly above 30,000 tons. [ABSTRACT FROM AUTHOR]

• A green multi-objective waste collection problem is modeled. • The amount of waste demand for each customer is stochastic. • A multi-objective optimization algorithm based on machine learning is proposed. • A case study is done for a real waste collection problem in a certain area of Beijing. Most of the existing municipal waste management (MWM) systems focus on the optimization of the waste disposal center locations and waste collection paths, which can be modeled based on the location-routing problem (LRP). This study models a green MWM system by a three-objective location-routing problem to achieve equilibrium among the total cost, carbon emission, and residential satisfaction. The amount of waste demand for each customer is considered as an independent discrete random variable following a normal distribution. The multi-objectives and non-deterministic characteristics make this problem more intractable than the traditional LRP. A multi-objective optimization algorithm based on decision tree classifier is proposed for solving this problem. The decision tree classifier learns from previous searching experience, and then guides the following evolution process to avoid blind searching. The experimental results show that the proposed algorithm has high competitiveness compared with other state-of-art methods. A case study is also conducted for a real waste collection problem in a certain area of Beijing. The proposed method adopts efficient location-routing strategies to balance the total cost, carbon emissions, and distance between residential areas and waste disposal centers. [ABSTRACT FROM AUTHOR]

• Human occupational exposures to phthalates are of great concern. • Waste management employees were significantly exposed to phthalate esters. • DEHP exposure among compost and processing groups can pose a definite risk. Humans are at risk of exposure to phthalates due to the widespread use of plasticized plastics, and one of the major concerns is occupational exposure. The present study investigated occupational exposure to phthalates at one of the greatest solid waste management sites in the second-largest country in the Middle East. Carcinogenic and non-carcinogenic health risks were assessed by human biomonitoring (HBM). The concentration of phthalate esters was determined using gas chromatography-mass spectrometry (GC–MS), and the daily intake (DI) of phthalate was calculated based on the adjusted urinary creatinine concentrations. Moreover, carcinogenic and non-carcinogenic risks were assessed. Monte Carlo simulations were performed for uncertainty and sensitivity analysis. The highest concentration recorded was 130.80 µg/g creatinine for mono-ethyl phthalate (MEP) among the composting group, while the lowest concentration was 0.49 µg/g creatinine for Monobenzyl phthalate (MBzP) among the office group. All estimates of daily intake were below the reference concentration, and differences between the DI at site sections were statistically significant (p < 0.05). The non-carcinogenic risk level was negligible. The excess lifetime cancer risk (ELCR) values corresponding to di-(2-ethylhexyl) phthalate (DEHP) exposure were 2.07E-04 among the composting group and 2.07E−04 among the processing group, posing a definite risk. The carcinogenic risk value among the office group was in a possible risk category with ELCR values of 9.75 E−05. The on-site workers of waste management sites can be highly exposed to phthalates, and their health risk is considerable. Appropriate measures and interventions should be considered to reduce occupational exposure to phthalates. [ABSTRACT FROM AUTHOR]

• Food waste ground by food waste disposers is easier to block pipes. • Liquid bridge force is the internal cause of deposits to aggregate. • Diameter of aggregations is positively correlated with adhesion on pipes. • Reducing particle size or choosing CI or HDPE pipes may reduce blockage. Food waste disposers (FWDs) streamline kitchen waste management and facilitate waste classification, whether they would increase the potential of blockage in kitchen drainage system is still unknown. This study conducted a theoretical analysis of the interactive forces between fat, oil, and grease (FOG) deposits and their aggregation on pipe walls. The study involved grading food waste particles processed by FWDs using sieving and weighing techniques to determine the mean weight diameter (MWD) of various aggregations. A full-scale experimental system, implemented in a 60-m high test tower, simulated blockages in horizontal pipes of high-rise buildings. The effect of pipeline materials and particle sizes on blockage were examined by measuring the adhesion of deposits on horizontal pipes. Energy dispersive spectrometer (EDS) analysis suggested that liquid bridge force is a primary factor in aggregate formation. Hand-cut particles formed aggregates with the highest MWD value. Particle size analysis revealed that sizes ranging from 2.36 to 4.75 mm, 1.18–2.36 mm, and 0.60–1.18 mm constituted over 80 % of particles ground by FWDs, with an average size of 2.16 mm. Results of full-scale experiment indicate particle diameters, friction coefficients and lipophilic coefficient significantly affected the propensity of these aggregates to adhere to pipes. Notably, particles processed by FWDs tended to cause blockages more frequently than hand-cut particles. These findings elucidate the deposition mechanism of FOG deposits and offer strategies to reduce blockages in kitchen drainage systems, such as reducing current grinding particle size by 18 % to 1.77 mm or selecting pipes like cast iron and high-density polyethylene. [ABSTRACT FROM AUTHOR]

Ceramic concretes, with their exceptional durability and ability to incorporate a high percentage of heavy metal oxides, are of critical importance for nuclear radiation facilities, offering superior radiation attenuation characteristics essential for long-term safety and protection. This study presents a detailed evaluation of the gamma-ray shielding properties of various concrete composites, including Standard Concrete and Heavy Concretes (HC series), with densities ranging from 1.94 g/cm3 to 4.54 g/cm3. Utilizing computational methods, we analyzed several gamma-ray and neutron shielding parameters such as mass attenuation coefficients, linear attenuation coefficients, half and tenth value layers, mean free paths, exposure build-up factors, effective atomic number (Z eff), effective electron density (N eff), fast neutron effective removal cross-section (Σ R), and photon transmission factors (TFs). Our research reveals that the shielding efficacy of concrete is intrinsically linked to its density and elemental composition, with higher densities and the incorporation of heavy elements leading to enhanced attenuation capabilities. Among the concretes studied, Limonite with Steel Punch LS-a, which contains 74.53% Fe in its structure, exhibited the lowest transmission factors (TFs) across all tested thicknesses and energy levels (0.662, 1.1732, and 1.3325 MeV), indicating its superior photon attenuation potential. It can be concluded that the concrete samples with a higher Fe (iron) content in their structure demonstrate clear superiority in gamma-ray attenuation properties. [ABSTRACT FROM AUTHOR]

Low production costs and a potential feedstock supply make lignocellulosic ethanol (bioethanol) an important source of advanced biofuels. The physical and chemical preparation of this kind of lignocellulosic feedstock led to a high ethanol yield. In order to increase the yield of fermentable sugars, pretreatment is an essential process step that alters the lignocellulosic structure and improves its accessibility for the expensive hydrolytic enzymes. In this context, the chemical composition of sugarcane trash (dry leaves, green leaves, and tops) and jatropha (shell and seed cake) was determined to be mainly cellulose, hemicellulose, and lignin. Hydrogen peroxide and sodium hydroxide were applied in an attempt to facilitate the solubilization of lignin and hemicelluloses in five agrowastes. The extraction of hydrogen peroxide was much better than that of sodium hydroxide. A comparative study was done using SEM, EDXA, and FTIR to evaluate the difference between the two methods. The pretreated wastes were subjected to saccharification by commercial cellulases (30 IU/g substrate). The obtained glucose was fortified with nutrients and fermented statically by Saccharomyces cerevisiae F-307 for bioethanol production. The results revealed the bioethanol yields were 325.4, 310.8, 282.9, 302.4 and 264.0 mg ethanol/g treated agrowastes from green leaves of sugarcane, jatropha deolied seed cake, tops sugarcane, dry leaves of sugarcane, and jatropha shell, respectively. This study emphasizes the value of lignocellulosic agricultural waste as a resource for the production of biofuels as well as the significance of the extraction process. • The chemical composition of sugar cane trash was determined to be mainly cellulose, hemicellulose, and lignin. • Hydrogen peroxide was the most suitable for the pretreatment of different cellulose types. • The pretreatment wastes were subjected to a fermentation procedure after being saccharified by cellulase. • All pretreated wastes recorded high ethanol yields to different degrees. [ABSTRACT FROM AUTHOR]

• Six types of campus fallen leaves were collected to produce biochar at 300 °C. • Adsorption capacity of leaf biochars for Pb vary from 31 to 209 mg/g. • Intraparticle diffusion controlled the adsorption kinetics of Pb onto PB. • 27% of total adsorbed Pb existed as the exchangeable fraction on PB. • Hydrocerussite and cerussite contributed to the great acid soluble Pb on YDB. Realizing campus sustainability requires the environmental-friendly and economical treatment of tremendous fallen leaves. Producing fallen leaf biochar at a low temperature is a candidate approach. In this study, six common types of fallen leaves on the campus were pyrolyzed at 300 °C. The obtained biochars were characterized and the adsorption mechanisms of lead (Pb) by the fallen leaf biochars were investigated. The adsorption capacity of leaf biochar for Pb was relatively high, up to 209 mg/g (Yulania denudata leaf biochar). Adsorption of Pb onto active sites was the rate-limiting step for most leaf biochars. But for Platanus leaf biochar, intraparticle diffusion of Pb2+ dominated owing to the lowest adsorption capacity. However, the highest exchangeable Pb fraction (27%) indicated its potential for removing aqueous Pb2+. Ginkgo and Prunus cerasifera leaf biochar immobilized Pb by surface complexation and precipitation as lead oxalate. Hence, they were suitable for soil heavy metal remediation. This study shed the light on the sustainable utilization of campus fallen leaves and the application of fallen leaf biochars in heavy metal remediation. [Display omitted] [ABSTRACT FROM AUTHOR]

• Biohythane from two-stage anaerobic digestion (TSAD) of food waste (FW) is reviewed. • Main principle and influence factors of the TSAD of FW are identified. • Main strategies for enhancing biohythane from TSAD of FW are summarized. • Future research directions for biohythane from TSAD of FW are proposed. The biotransformation of food waste (FW) to bioenergy has attracted considerable research attention as a means to address the energy crisis and waste disposal problems. To this end, a promising technique is two-stage anaerobic digestion (TSAD), in which the FW is transformed to biohythane, a gaseous mixture of biomethane and biohydrogen. This review summarises the main characteristics of FW and describes the basic principle of TSAD. Moreover, the factors influencing the TSAD performance are identified, and an overview of the research status; economic aspects; and strategies such as pre-treatment, co-digestion, and regulation of microbial consortia to increase the biohythane yield from TSAD is provided. Additionally, the challenges and future considerations associated with the treatment of FW by TSAD are highlighted. This paper can provide valuable reference for the improvement and widespread implementation of TSAD-based FW treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

• Interaction of plastic and scrap tyre during co-pyrolysis is plastic-specific. • Mixing PP or LDPE with tyre can promote aliphatic hydrocarbon and suppress PAHs. • Mixing PS with tyre can suppress PAHs and enhance MAs production, especially BTEX. • 75 wt% LDPE or PS with tyre at 600 °C yields sulphur-free pyrolytic oil. • Tyre char can promote cracking reactions in LDPE thermal degradation. Fast co-pyrolysis offers a sustainable solution for upcycling polymer waste, including scrap tyre and plastics. Previous studies primarily focused on slow heating rates, neglecting synergistic mechanisms and sulphur transformation in co-pyrolysis with tyre. This research explored fast co-pyrolysis of scrap tyre with polypropylene (PP), low-density polyethylene (LDPE), and polystyrene (PS) to understand synergistic effects and sulphur transformation mechanisms. A pronounced synergy was observed between scrap tyre and plastics, with the nature of the synergy being plastic-type dependent. Remarkably, blending 75 wt% PS or LDPE with tyre effectively eliminated sulphur-bearing compounds in the liquid product. This reduction in sulphur content can substantially mitigate the release of hazardous materials into the environment, emphasizing the environmental significance of co-pyrolysis. The synergy between PP or LDPE and tyre amplified the production of lighter hydrocarbons, while PS's interaction led to the creation of monocyclic aromatics. These findings offer insights into the intricate chemistry of scrap tyre and plastic interactions and highlight the potential of co-pyrolysis in waste management. By converting potential pollutants into valuable products, this method can significantly reduce the release of hazardous materials into the environment. [ABSTRACT FROM AUTHOR]

• A methodology that defines and ranks KPIs encompassing the entire FSC. • A KPIs co-creation process involving experts and FSC stakeholders. • A new criteria (SMART +) that incorporates the digitization capability of KPIs. • An index that assesses the readiness of FSCs to implement FLW prevention strategies. The impact of food loss and waste (FLW) generation on food supply chains' (FSC) sustainability represents a challenge embodied in the Sustainable Development Goal (SDG) 12.3. This problem requires a methodology to measure such an impact in a rigorous, holistic, and standardized way that can be applied to any FSC. This paper aims to develop and validate a single index to assess the readiness of FSCs to implement FLW prevention strategies and measure their impact: the so-called FOODRUS index. The co-creation methodology followed incorporates experts and FSC stakeholders feedback. The index has been validated in 3 FSCs: The Slovak pilot scored 74.35%, the Spanish pilot reached 68.79%, and the Danish pilot was rated 61.14%. Its calculation, eased by the FOODRUS index self-assessment tool (described in the Appendix), allows quick diagnosis of the FSC capability to implement FLW prevention strategies considering both the knowledge provided by experts and the experience of the FSC stakeholders that participated in its co-creation process. In this way the FSC can assess its FLW prevention performance at a strategic and management level, with the aim of improving its sustainability impact. [ABSTRACT FROM AUTHOR]

• A novel method to conduct waste characterization for RDF3 production application. • Detect and classify single and multi-family waste using video data. • Smart Sight uses computer vision for frame extraction & enhancement. • Solution's waste estimates compared with lab results, showing high accuracy. A material recovery facility (MRF) can transform municipal solid waste (MSW) into a valued commodity called refuse-derived fuel (RDF) as a promising solution to waste-to-energy conversion. The quality of the produced RDF significantly relies on the composition of in-feed waste and waste characterization method applied for auditing purposes, a process that is both time-consuming and fraught with potential hazards. This study focuses to enhance the workflow of the waste characterization process at an MRF. A solution named Smart Sight is proposed to detect and classify waste based on videos recorded after processing MSW through a mechanical sorting line consisting of bag breakers and trommel screens. A comprehensive dataset is created encompassing thirteen mixed waste classes from single and multi-family streams. The dataset is preprocessed with motion compensation techniques and frame differencing methods to extract and refine valuable frames. A one-stage YOLO detector model is then trained over the dataset. The experimental results show that the proposed method works efficiently at detecting and classifying waste objects in indoor MRF environments. Accuracy, precision, recall, and F1 score related to the proposed solution are found to be 0.70, 0.762, 0.69 and 0.72, respectively, with a mAP@0.5 of 0.716. The proposed approach is validated using data collected from local MRF by comparing the estimated waste composition values of the proposed solution with laboratory results obtained through current standardized industrial practices. Comparison reveals that waste characterization estimation obtained is consistent with the laboratory results, inferring that Smart-Sight is a viable tool for estimating waste composition. [ABSTRACT FROM AUTHOR]

• Waste from public spaces is currently predominantly collected as mixed waste. • The composition of public waste differs from household waste. • High proportions of recyclable materials and packaging waste were identified. • The case city's annual public waste generation is around 100 tonnes. Waste from public places like parks, pedestrian zones or sidewalks is a visible yet unexploited waste stream. Publications and information on the amounts and makeup of this waste flow are very scarce. To evaluate the resource potential and enable waste management planning, this study aims to assess the quality and quantity of public waste in a detailed waste characterisation campaign. For the first time, an analysis at this level of detail was conducted in a medium-sized town (25,000 inhabitants) in Austria. The sampling campaign included the whole town area. In total, almost 1000 kg of waste was sorted in up to 88 different fractions, which allows the detailed composition of, for example, packaging waste and single-use plastics to be delineated. We found that the amount of waste collected in public street bins is approximately 2.6 % of the total mixed municipal solid waste, resulting in 4.1 kg of public waste per inhabitant annually. The vast majority of this waste is currently collected as mixed waste. The results indicate a high share (52 %) of recyclable materials (glass, metal, paper and lightweight packaging) in mixed public waste, most of which is packaging (44 % of total waste). Other large shares include dog feces (18 % of total waste) and biogenic waste (17 % of total waste). The results lay the foundation for further investigations into, for example, exploiting recycling potential or evaluating possible improvements in separate waste collection in public spaces. Further, the collected data serve as an essential knowledge basis for policymakers and local authorities. [ABSTRACT FROM AUTHOR]

• The recycling potential of waste wood could increase when knowing its composition. • The best recycling option is defined dividing waste wood into three categories. • To this aim three different classification models were developed and compared. • Results suggest the best setting for getting good classification accuracy. • Near Infrared Spectroscopy can be used as a tool for waste wood real-time sorting. Recycling of post-consumer waste wood material is becoming an increasingly appealing alternative to disposal. However, its huge heterogeneity is calling for an assessment of the material characteristics in order to define the best recycling option and intended reuse. In fact, waste wood comes into a variety of uses/types of wood, along with several levels of contamination, and it can be divided into different categories based on its composition and quality grade. This study provides the measurement of more than a hundred waste wood samples and their characterisation using a hand-held NIR spectrophotometer. Three classification methods, i.e. K-nearest Neighbours (KNN), Principal Component Analysis – Linear Discriminant Analysis (PCA-LDA) and PCA-KNN, have been compared to develop models for the sorting of waste wood in quality categories according to the best-suited reuse. In addition, the classification performance has been investigated as a function of the number of the spectral measurements of the sample and as the average of the spectral measurements. The results showed that PCA-KNN performs better than the other classification methods, especially when the material is ground to 5 cm of particle size and the spectral measurements are averaged across replicates (classification accuracy: 90.9 %). NIR spectroscopy, coupled with chemometrics, turned out to be a promising tool for the real-time sorting of waste wood material, ensuring a more accurate and sustainable waste wood management. Obtaining real-time information about the quality and characteristics of waste wood material translates into a decision of the best recycling option, increasing its recycling potential. [ABSTRACT FROM AUTHOR]

• Generalized Kelvin-Voigt model was able to simulate waste settlement. • Increase in stiffness with applied stress in GKV springs captured field observations. • Coupled temperature and settlement field data are essential for model validation. • Waste disposal under freezing temperatures delays waste stabilization. In Northern climates, waste placed curbside the evening before waste collection can lead to partially frozen waste at placement, which delays biodegradation and biodegradation-induced settlement. A 12-year settlement dataset collected during the filling and post-closure phases at a landfill in Québec, Canada was analyzed. The dataset showed a delay in biodegradation-induced settlement due to the first three waste lifts being placed in the winter months and exhibited an increase in the settlement rate at later times when the waste temperatures increased to values that support biodegradation. The field data also demonstrated that the stiffness of MSW increased in response to confined stress as subsequent waste lifts were added. A thermal–mechanical-biological (TMB) model was developed, in COMSOL Multiphysics, to simulate the settlement dataset. TMB integrates a Generalized Kelvin-Voigt (GKV) model, simulating instantaneous and mechanical creep settlements, with a biodegradation-induced settlement model that relates heat/gas generation with time to biodegradation-induced settlement. The thermal model simulates heat transfer through conduction and includes a biodegradation heat generation source term. The GKV stiffness parameters are expressed as a function of the applied stress to account for waste compressibility effects on mechanical response, which is consistent with field data and the research literature. The paper focuses solely on the MSW settlement field data and model predictions, with thermal response analysis presented in a separate publication. The TMB model effectively predicted waste behaviour, including resistance to compressibility under higher stress and the delay in waste settlement for waste placed in winter. The temperature and settlement data provide a valuable dataset to validate different models that can be used to predict waste settlement in cold regions. [ABSTRACT FROM AUTHOR]