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[Display omitted] • A new framework to quantify key components of municipal solid waste (MSW) residues. • Hydrothermal liquefaction (HTL) yields validate results of the proposed framework. • Biooil yields are correlated with the cellulose content of MSW residues. • MSW residue plastic fractions are recovered in HTL solids products. • HTL is suitable for high-ash content MSW residues. This paper presents and evaluates a new method for characterising municipal solid waste residues for assessing the performance of thermochemical conversion technologies to produce fuels. The method combines information from three complementary analytical techniques to estimate the quantity of key organic waste fractions and was demonstrated using two commercial waste residues: 'BRDF' and 'Floc' produced from the mechanical processing of domestic waste. Cellulose content (mostly paper and textiles) is estimated using acid hydrolysis, while thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) are combined to determine the plastics (LDPE and PET) and non-volatile fractions such as lignin of the wastes. High mass balance closures were achieved for both residues, although the nature of the non-volatile fraction was difficult to verify. Hydrothermal liquefaction (HTL) of cellulose rich BRDF (34.0% cellulose) produced much higher biooil yields than Floc (26.8% and 12.2%, respectively), with a cellulose content of only 22.4%. In both cases, most of the plastic and non-volatile waste fractions partitioned into the solid HTL product, representing a potential method for separating the plastic fractions from other waste components. Importantly, this combined waste characterization method can be used for characterization of any municipal waste residue using acid hydrolysis, TGA and FTIR data, providing accurate information about feedstock composition. It enables comparison between different waste valorisation studies of complex waste residues. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cone angle had great influence on plastic separation. • The recovery of particles with wide size distribution was studied. • The discrepancy of settlements of PET/PVC were significant. • The optimum cone angle and L/D were obtained. The cone angle of a hydrocyclone is believed to be an important parameter to affect the separation performance. For the recycling of waste plastics, this paper focused on the study of the influence of cone angles on the separation of light dispersed plastics (PET) and heavy dispersed plastics (PVC) by experiments and numerical simulations. The cone angle was changed from 3° to 28° either at given length of the cylindrical section or at fixed total length of the hydrocyclone. The separation performance varied with cone angles at given length of the cylindrical section more greatly than that at fixed total length of the hydrocyclone. Results show that particles with different sizes in mixture exhibited discrepant separation behaviors at various cone angles. There was an optimum cone angle at which the Newton efficiency peaked as 90.2%, while the purity of PET could also reach the highest. The proportion of cylindrical section could be properly small for the enhancement of Newton efficiency. [ABSTRACT FROM AUTHOR]

[Display omitted] • An effective RGB-D data acquisition platform is built. • The semi-automatic labeling method can greatly improve the labeling speed of dataset. • The models can accurately segment the contours of objects while classifying them. • The proposed model can obviously improve the detection accuracy than the RGB model. The development of urbanization has brought a large amount of construction and demolition waste (CDW), which occupy land and cause adverse ecological effects. To effectively solve the negative impact of CDW, it needs to be recycled. Accurate waste classification is key to successful waste management. However, the current waste classification methods mainly use color images to classify, which cannot meet the needs of accurate classification. This paper built an RGB-depth (RGB-D) detection platform, using a color camera and a laser line-scanning sensor to collect RGB images and depth images. In order to use RGB images and depth images for feature fusion more effectively, this paper proposed three fusion models: RGB-D concat、RGB-D Ci-add and RGB-D Ci-concat. All these models based on an instance segmentation network called mask region convolutional neural network (Mask R-CNN), which can accurately segment the contours of each object while classifying them. The experimental results show that the mAPs of the RGB-D Ci-add / concat model are 1.33% to 1.72% higher than those of the RGB model, and the classification accuracy is 1.92% ∼ 2.27% higher. In addition, all the proposed models can meet the real-time requirement of online detection. Due to the excellent comprehensive performance of the RGB-D Ci-concat model, it can be regarded as the final detection model of the robot, which can improve the sorting efficiency of CDW further. [ABSTRACT FROM AUTHOR]

• Landfill monitoring using unmanned aerial systems. • Control and management of landfills and dumpsites. • Drone technology in municipal solid waste management. The paper discusses the experience of using unmanned aerial vehicles (UAV) in the management of municipal solid waste landfills and dumpsites. Although the use of drones at waste disposal sites (WDS) has a more than ten-year history, the active application of these technologies has increased in the last 3–4 years. The paper analyzes scientific publications of 2010–2021 (July) and identifies the main WDS management task groups for which the solution of UAV can be used. It illustrates that most of the research is devoted to studying spatial and volumetric characteristics of landfills, which is connected with the practical needs. About a quarter of the publications focus on monitoring the emissions of landfill gas or its individual components, mainly methane. Issues of a comprehensive assessment of the technological and environmental safety of landfills and dumps are covered in the scientific literature fragmentarily and insufficiently. At the same time, the current level of technologies for collecting and processing remote sensing air data (UAV, sensors for aerial imagery, software for photogrammetric processing of aerial imagery data, geographic information systems (GIS)) makes it possible to identify and assess many environmental effects of landfills and dumps and to monitor compliance with the standards for the landfills operation, which could bring management of these facilities to a fundamentally different level. Promising areas of further research in the field of UAV application at WDS are indicated: development of processes for automatic interpretation of aerial imagery materials; product analysis of photogrammetric data processing in a GIS environment, etc. [ABSTRACT FROM AUTHOR]

• Smoldering and ignition temperature were determined for aged waste components. • Spontaneous ignition time of aged waste for field-scale was determined. • A correlation was established between ignition time and moisture content. • Spontaneous ignition was dependent on the heat gained at the dumpsite surface. Open municipal solid waste (MSW) dumpsites in India are significant hotspots of spontaneous fire and associated air and ground water pollution. Unscientific dumping of MSW poses a major threat to the surrounding environment and human health. One-year-old biodegradable waste components comprised of paper, cardboard, newspaper, textile, wood, grass leaves and coconut shell were analyzed for the determination of the moisture content (MC), smoldering temperature, ignition temperature, and ignition time. Principal component analysis of the old waste components revealed that cardboard, paper, newspaper and leaves are most susceptible waste components for spontaneous ignition. In contrast, MC was the most influential parameter for resulting changes in ignition temperature (0C) on ignition time (min). A numerical equation was developed to estimate the time required for the spontaneous waste ignition at MSW dumpsite. The results of the study showed that the aged waste (age ≥ 3 year) having MC below 6 % and initial surface temperature of 78 0C might smolder and ignite during the hottest time of the day in ∼ 6 and ∼ 26 days, respectively. Estimates showed that the time required for spontaneous waste ignition of aged waste is moderately dependent on waste MC (∼5–55 %), surface temperature (∼40–100 0C), monthly pattern of average high temperature (∼36.6–42.6 0C), biodegradable waste components having smoldering temperature ≤ 150 0C and ignition temperature ≤ 270 0C. The present study also showed that the occurrence of landfill fire events at MSW dumpsites is more prominent during the pre-monsoon season i.e. during the elevated temperature level. [ABSTRACT FROM AUTHOR]

Highlights • The perceptions, practices and willingness to pay for continued use of plastic bags were investigated in South Africa. • The high usage of plastic bags was primarily attributed to convenience. • Age, gender, and education level influenced consumers' willingness to pay for plastic bags. • Potential interventions for reducing plastic bag use are discussed. Abstract Single-use plastic shopping bag consumption is one of the leading causes of environmental and socio-economic problems worldwide, which has led to global calls for intervention strategies to reduce use. In South Africa, plastic bag use is still widespread despite intervention efforts based on levying taxes. Using an online questionnaire, this study examines plastic bag use practices and factors influencing use in South Africa. The results show that the majority of respondents perceived there was a plastic bag use problem in the country but still highly used plastic bags because it was convenient to do so. Factors like, gender, age, education and environmental consciousness influenced people's willingness to pay for plastic bags but the relationships were generally weak. The paper outlines which interventions might be most effective in achieving pro-environmental actions. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Traces of papers greatly affect mechanical properties and processibility of PC-PET. • PE traces, caps and rings, has less effect on moldability of PC-PET. • When processing post-consumer PETs, allow no papers within the PET waste stream. • Number of melt processing steps should be minimized when reprocessing PC-PET. Abstract In this research, post-consumer polyethylene terephthalate (PC-PET) bottles were processed and characterized. The aim was to investigate the influence of number and type of melt processing steps and the presence of contaminants on the mechanical properties and moldability of PC-PET. Results and observations of current research showed that direct processing of PC-PET by injection molding (i.e. skipping melt extrusion step) is preferable in order not to deteriorate mechanical properties especially the toughness of PC-PET. Contaminants found in PC-PET waste stream include labels and bottle cap rings made of polyethylene (PE) and paper labels. Unlike PE contaminants, paper contaminants can drastically reduce toughness of PC-PET and severely affect its moldability. Molded samples of PC-PET containing traces of papers appeared incoherent and fragmented pieces due to poor adhesion between PET and papers. The recommendation given by current research is to remove paper contaminants from PC-PET waste stream before melt processing and melt processing steps should be limited. [ABSTRACT FROM AUTHOR]

[Display omitted] • Iron-phosphorus residue (IPR) mainly consists of FePO 4 ·2H 2 O and valuable metals. • The leaching behaviors of IPR in different leaching systems were discussed. • Over 95% of Fe, Ni, Co, V, and Mo were extracted by HCl atmospheric leaching. • The mechanism of atmospheric leaching was analyzed by XRD, XPS, and FTIR. The method of extracting valuable metals from spent catalysts has been developed in recent years. In this paper, the solid waste produced in the treatment of spent catalyst was studied and named iron-phosphorus residue (IPR). IPR was composed of FePO 4 ·2H 2 O, Fe 3 (PO 4) 2 ·3H 2 O, Fe 5 (PO 4) 4 (OH) 3 ·2H 2 O, and SiO 2. Appreciable quantities of Ni, Co, V, Mo, and W were detected in IPR. Based on E-pH diagrams, different atmospheric leaching strategies were used to extract valuable components from IPR. Both the HCl and NaOH leaching are appropriate for treating IPR. An in-depth investigation on HCl atmospheric leaching showed that >95% of Fe, Ni, Co, V, and Mo, 76.9% of W, and 89.3% of P were extracted efficiently and SiO 2 was enriched into the leach residue, at leaching temperature of 90 ℃, leaching time of 180 min, initial HCl concentration of 5 mol/L and liquid to solid ratio of 8:1 mL/g. The leaching mechanism was discussed via XRD, XPS, and FTIR. An efficient and green process for the recovery of valuable components in IPR has been developed. This research achieves the sufficient extraction of valuable components in IPR and provides significant guidance for the management of similar solid waste. [ABSTRACT FROM AUTHOR]

• A novel Lotka-Volterra model describes the microbial competition in composting. • Time-varying parameter matrix reflects the variation of microbial interaction. • The influence of biological agents on the microbial competition can be analyzed. Aerobic compost is an effective method for the treatment of livestock manure, which is usually accompanied by complex interspecific competition. Describing these competitive relationships through mathematical models can help understand the interaction of microorganisms and analyze the effect of exogenous additive to regulate the composting process. The common model for analyzing competition problem is the Lotka-Volterra model. However, the fixed parameters of the Lotka-Volterra model are not suitable to reflect the dynamic variations of the competitive relationship when the environmental conditions change during composting process. Therefore, this paper establishes a novel fractional grey unequal-interval time-varying Lotka-Volterra model. Firstly, a fractional grey derivate operator is proposed on the basis of the unequal interval of composting data and historical dependence of microbial growth. Secondly, considering the influence of temperature, a time-varying parameter matrix is defined to reflect the variation of competitive relationship at different composting phases, and it is estimated by forgetting factor recursive least squares. Thirdly, the optimal coefficients are optimized by grey prediction evolution algorithm. Finally, the proposed model is employed to analyze the chicken manure composting experiment. The results show that the proposed model has lower error criteria and more accurate trend of fitting curve than the other five existing models. The parameter matrix describes the dynamical variation of microbial competitive relationship in two taxonomic levels and reveals that effect of the exogenous additive is principally reacted in the thermophilic phase and the competitive advantage is shifted from Bacteroidota to Firmicutes after treatment with the exogenous additive. [ABSTRACT FROM AUTHOR]

[Display omitted] • The harmful diamond wire saw silicon powder was leached with HCl to remove Fe. • The optimal conditions for the leaching of Fe from HCl solution were investigated. • The leaching kinetics of Fe was analyzed by heterogeneous and homogeneous model. • The Fe leaching from DWSSP fits the secondary reaction model of homogeneous model. • The work provides an important guide for preparation of high purity silicon. The diamond wire saw silicon powder (DWSSP) is considered to be a harmful to the environment because of finer particles, the large specific surface area and flammability. Removal of Fe impurity is very essential for recovering Si from DWSSP due to the large amount of Fe introduced during the silicon powder generation process. In the study, the thermodynamics of Fe leaching with HCl was analyzed and determined iron was theoretically present as ions in solution. Furthermore, the effects of different concentrations, temperatures and liquid–solid ratios on Fe leaching from HCl were investigated. The leaching rate of Fe reached 98.37% at the optimal parameters (HCl concentration of 12 wt%, leaching temperature of 333 K, liquid–solid ratio of 15 ml/g) with 100 min. The leaching kinetics of Fe in HCl was analyzed by shrinking core model and homogeneous model, respectively. The study indicated the process of leaching Fe from DWSSP conforms to the secondary reaction model of homogeneous model which coincided with the porous structure of DWSSP due to agglomeration. The apparent activation energy required (49.398 kJ/mol) in the first stage is lower than that (57.817 kJ/mol) in the second stage because of the porous structure. In conclusion, this paper provided a suitable way to purify the diamond wire saw silicon powder. This work provides an important guide for the industrial recovery and preparation of high purity silicon from DWSSP by the most environment-friendly and low-cost approach. [ABSTRACT FROM AUTHOR]

• A two-year field investigation for H 2 S emission at a large-scale landfill. • Comprehensive evaluation of H 2 S concentration and flux on the cover. • Estimation of H 2 S diffusion coefficient using developed analytical model. • Visualization of H 2 S diffusion patterns and pathways using the CALPUFF. This paper presents the study on the variation, influencing factors and diffusion regularity of hydrogen sulfide (H 2 S) concentration and surface flux on the working face and intermediate geomembrane cover of a landfill. Field investigations were conducted using static chambers at a large-scale municipal solid waste landfill in Hangzhou, China, from January 2019 to June 2021. The analytical models of H 2 S transport in the working face and intermediate cover were developed to investigate the surface flux under various conditions. The CALPUFF model was used to demonstrate the diffusion path. The H 2 S surface flux on the working face ranged from 7.1 × 10−3 to 1.7 mg/m2/h, whereas the range was found to be 1.5 × 10−4 to 0.9 mg/m2/h on the intermediate geomembrane cover. This observation indicated that the geomembrane can reduce H 2 S emissions. In addition, the H 2 S surface fluxes at the HDPE GMB seams and near the gas collecting wells were generally 1–2 orders of magnitude larger than that in the intact GMB. The analytical model estimates that the intact GMB exhibits a diffusion coefficient of H 2 S ranging from 2.7 × 10−11 to 2.2 × 10−10 m2/s. However, the diffusion coefficient increases significantly to a range of 3.3 × 10−11–9.8 × 10−7 m2/s on the GMB seams. According to CALPUFF results, only the H 2 S diffusion from the working face had areas exceeding the standard concentration. [ABSTRACT FROM AUTHOR]

• The financial and ecological viability of power from pyrolysis oil is assessed. • The process has high oil yield and power generation potential. • The project is economically feasible and profitable in China. • Power generation from the project contributes to global warming. • Consumption of power from the project reduces coal usage and global warming. The increased plastic waste generation worldwide poses ponderous issues for public health and the environment. China is the highest generator of plastic waste around the world. The current treatment process (incineration) of the increased plastic waste causes dangerous environmental consequences. Pyrolysis has recently surfaced as an ecologically friendly technique for energy and material recovery from plastic waste. The present study assesses the financial and ecological viability of power production from oil derived from the pyrolysis of mixed plastic wastes in China from 2009 to 2028. The prominent findings show that the amount of plastic waste collected in 2020 (24.16 Mt) increased by 53.19% in 2028.The pyrolysis of mixed plastic wastes during the project period yielded 359.29 Mt oil, which has a power potential of 1,060.86 GWh. The economic analysis indicated the project is viable and profitable with a positive net present value (US$8.80 million) and profitability index (1.26) greater than 1. The project has 10.6 y payback period, US$0.0752/kWh levelized cost of energy, 22.5% return on investment, and 13.0% internal rate of return. The life cycle assessment results show that conversion of mixed plastic waste to pyrolysis oil for electricity generation during the project period has a total global warming potential (GWP) of 1,311.4 kt CO 2 eq. The GWP is mainly from conversion of pyrolysis oil to electricity (73.42%), pyrolysis oil production (15.01%) and upgrading of pyrolysis oil (11.38%). The consumption of power from the project could avoid the combustion of 2,659.0 t coal, minimizing global warming by 11,278.8 kt CO 2 eq. Sensitivity analysis, which examines the influence of variation in sensitive factors on the success of the project, is presented. This paper provides scientific strategies for optimal investment and decision-making on the environmental sustainability of plastic waste-to-energy pyrolysis projects. [ABSTRACT FROM AUTHOR]

[Display omitted] • Management of organic fraction of MSW (OFMSW) and excess sludge is difficult. • Anaerobic codigestion of these two substrates in presence of bioplastic is analyzed. • Influence of bioplastics on methane production has not been evidenced. • Bioplastic biodegradation is very limited and the presence of fragments is evident. • A possible increase in phytotoxicity has been also signalized. Co-digestion of the organic fraction of municipal solid waste (OFMSW) and excess sludge has several benefits especially related to improved methane production and better process stability. In recent years, the presence of biodegradable plastics is increasingly common in OFMSW especially since, as in Italy, biodegradable bags are used for its collection. In this paper, the influence and the fate of biodegradable bags during anaerobic co-digestion of excess sludge and OFMSW are assessed. The best results in terms of methane yield (about 180 NmL/g VS) have been obtained with the 50:50 (VS basis) co-digestion of excess sludge and OFMSW with an organic loading rate of 2 kg VS /m3·d. Bioplastic degradation is very limited during the co-digestion but it does not influence methane production or digestate chemical characteristics. However, the feeding of bioplastic bags seems to induce a higher phytotoxicity and the presence of undigested fragments is anyway a problem for further treatment or direct utilization of digestate. [ABSTRACT FROM AUTHOR]

• The pyrolysis characteristics and components separation of EWTB were studied. • OER decomposition was a diffusion-controlled single-step reaction process. • Fixed-bed pyrolysis temperature range of EWTB was verified 400 ∼ 600 °C. • Bisphenol A in pyrolytic liquids could be recovered for epoxy resin synthesis. • The OER and the inorganic fiberglass were almost completely separated at 550 °C. After the peak of rapid wind power development, a large amount of wind turbine blades reach/exceed their service life due to aging or damage. These ex-service wind turbine blades (EWTB) will increase the issue of its high-efficient utilization in the future decades. Among several treatment methods, pyrolysis has been considered as a promising solution to separate inorganic fiberglass and make organic epoxy resin (OER) high-value-added converted. However, the pyrolysis mechanism, chemical composition, and fiberglass separation of EWTB have not been deeply studied. In this paper, the synthetic model compound of epoxy resin was firstly used to investigate the thermal weight loss and pyrolysis kinetics, the thermal weight loss temperature range of which was 300 ∼ 480 °C. The apparent activation energy was minimum when the conversion rate was 0.6, and the pyrolysis mechanism was determined by the Coats-Redfern method as a diffusion control. On this basis, a lab-scale fixed-bed was conducted to study fast-heating pyrolysis characteristics of EWTB. It could be analyzed that the chemicals in the pyrolytic liquid were a series of phenolics with methyl and vinyl substituted benzene rings (e.g., bisphenol A, p-isopropenyl phenol, and phenol). Bisphenol A presented a relatively high selectivity of 51.02%, which could be recycled as the main raw material for the synthesis of epoxy resins. Furthermore, clean fiberglass could be separated by combusting the residual carbon in pyrolytic solids. These results might be useful for achieving the separation and resource utilization of organic and inorganic components of EWTB. [ABSTRACT FROM AUTHOR]

• The MSW generation is related to social index, economic index and population index. • The Grey Relational Analysis method can improve the prediction performance accuracy. • The GRA-LSTM model precisely and accurately predict the MSW generation in Beijing. • Advice for urban development are proposed from the MSW source and the MSW disposal. Achieving accurate prediction of the Municipal Solid Waste (MSW) generation is essential for the sustainable development of the city. This paper selects Beijing as the research object, building a neural network model based on Grey Relational Analysis and Long and Short-Term Memory (GRA-LSTM), and choosing 14 influencing factors of MSW generation as the input indicators, to realize the effective prediction of MSW generation. Then this study obtains the landfill area in Beijing by using the aforementioned prediction results and the calculation formula of the landfill. Firstly, the GRA method is used to sort the influencing factors of the MSW generation for obtain the key influencing indexes. Secondly, the LSTM model is used to learn features of the key influencing indexes. Finally, the area of Beijing landfill is estimated by the calculation formula of landfill area. The results show that, first of all, the MAPE value of the GRA-LSTM combined model established in this paper is 7.3, and the prediction performance of this model is better than the other seven structural methods. Secondly, the area demand for landfills in Beijing shows an upward trend. At last, this paper put forward relevant suggestions to achieve sustainable urban development and deal with the increase in the MSW generation and the demand for landfills. [ABSTRACT FROM AUTHOR]

• The paper investigates the degree of social acceptance of biogas. • The determinants of citizens' perception of new biomass plants. • Two waves of surveys has handed out in order to assess an empirical strategy. • The paper provides some insights on the social acceptability of biogas. • Results assessed the biogas acceptability. The degree of social acceptance of biogas as a renewable green energy source is still somewhat disregarded. Although many initiatives have focused on the construction of new biogas plants around the world, local protests on the construction of new plants often arise. This study aims to analyse the determinants of citizens' perceptions regarding the construction of new biomass plants in their neighbouring areas. In particular, the focus is on prior knowledge of the production process of biogas as well as on other individual characteristics. The investigation is based on two repeated surveys conducted among the population living in two Italian areas where the construction of new large biogas plants were planned (the provinces of Oristano and Andria). The first survey analyses the main variables correlated with the degree of biogas acceptability particularly the biogas knowledge. The second survey (differentiated in two waves) focuses on the role of participatory processes and information campaigns undertaken by policy makers and environmental associations to increase the social acceptance of communities regarding the construction of new biogas plants. [ABSTRACT FROM AUTHOR]

[Display omitted] • The specific catalytic properties of oxygen vacancy were systematically explored. • The defect of metal oxide improved the utilization efficiency of microwave energy. • Syngas concentration in the bio-gas could reach 61.5 mol% with Fe 3 O 4 as a catalyst. • The lower heating value of light bio-oil was up to 30.45–31.21 MJ/kg. • Iron oxide provided reactive sites for CO 2 reduction to CO in microwave pyrolysis. This paper proposed to use ferric oxide (Fe 2 O 3) and ferroferric oxide (Fe 3 O 4) as catalysts with both microwave absorption and catalytic properties. Carbon dioxide (CO 2) was introduced as the reaction atmosphere to further improve the quality of biofuel produced by microwave pyrolysis of food waste (FW). The results showed the bio-gas yield and the syngas concentration (H 2 + CO) increased to 70.34 wt% and 61.50 mol%, respectively, using Fe 3 O 4 as the catalyst. The content of aliphatic hydrocarbons in bio-oil produced with the catalyst Fe 2 O 3 increased to 67.48% and the heating value reached 30.45 MJ/kg. Compared with Fe 2 O 3 catalyst, Fe 3 O 4 exhibited better microwave absorption properties and catalytic properties. Transmission electron microscopy (TEM) and Electron paramagnetic resonance (EPR) characterizations confirmed that the crystal surface of Fe 3 O 4 formed more oxygen vacancy defects and unpaired electrons. Additionally, according to the X-ray photoelectron spectroscopy (XPS) analysis, the content of lattice oxygen in Fe 3 O 4 was 14.11%, a value that was much lower than Fe 2 O 3 (38.54%). The oxygen vacancy defects not only improved the efficient utilization of microwave energy but also provided the reactive sites for the reaction between the volatile organic compounds (VOCs) and CO 2 to generate CO. This paper provides a new perspective for selecting catalysts that have both microwave absorption and catalytic properties during the microwave pyrolysis of biomass. [ABSTRACT FROM AUTHOR]

• Incinerator can be optimized without new investment by changing its operation setup. • Waste composition determines energy balance, cost and environmental impact. • Steady-state termination saves time and results reliable solutions in optimization. • Parameter sensitivity differs for economic, efficiency and environmental aspect. This paper presents a multi-objective optimization (MOO) of waste-to-energy (WtE) to investigate optimized solutions for thermal, economic, and environmental objectives. These objectives are represented by net efficiency, total cost in treating waste, and environmental impact. Integration of the environmental objective is conducted using life cycle assessment (LCA) with endpoint single score method covering direct combustion, reagent production and infrastructure, ash management, and energy recovery. Initial net efficiency of the plant was 16.27% whereas the cost and environmental impacts were 75.63 €/ton-waste and −1.21 × 108 Pt/ton-waste, respectively. A non-dominated sorting genetic algorithm (NSGA-II) is applied to maximize efficiency, minimize cost, and minimize environmental impact. Highest improvement for single objective is about 13.4%, 10.3%, and 14.8% for thermal, economic, and environmental, respectively. These improvements cannot be made at once since the objectives are conflicting. These findings highlight the significance role of decision makers in assigning weight to each objective function to obtain the optimal solution. The study also reveals different influence among decision variable, waste input, and marginal energy sources. Finally, this paper underlines the versatility of using MOO to improve WtE performance regarding the thermal, economic, and environmental aspects without requiring additional investment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Black liquor can be acidified with spent sulfuric acid to precipitate lignin. • Lignin can be used as a reducing agent in reutilization of steel waste. • Red dust, BOF scrap fines, IOF, mill scale can be used in geopolymeric material. • Replacing 30% of fly ash w/ mill scale in geopolymers increased compressive strength. Recycling wastes back into a manufacturing process, or into a separate product, is an important challenge. The primary aim of this work was to combine wastes from the steel industry, the galvanizing industry and the pulp and paper industry to form two new useful products. The steel industry generates the wastes red dust, mill scale, blast oxygen furnace slag and iron ore fines. Galvanizing industrial facilities dispose of sulfuric acid contaminated with iron. The pulp and paper industry produces the byproduct black liquor, which is high in lignin. Inserting these wastes as resources into the steel industry, or as stand-alone products, could reduce the need for virgin materials. The main methodology of the work was three-fold. First, spent sulfuric acid was used to precipitate the lignin from black liquor. Second, this lignin was combined with steel industry wastes and geopolymeric materials to make briquettes, a sustainable reducing material for steelmaking furnaces. Briquettes contained red dust, mill scale, blast oxygen furnace slag, iron ore fines and lignin precipitated from black liquor with spent sulfuric acid. Key research findings of compressive strength and weight loss testing showed the briquettes to be feasible for steel-making furnace use. Third, these steel industry wastes were investigated as a partial fly ash replacement in geopolymers. Main research findings were that compared to the control geopolymer, these geopolymer samples improved compressive strength and gave similar workability. Thus, the investigated wastes have the potential to both increase recycling in the steel industry and to improve geopolymeric products. [ABSTRACT FROM AUTHOR]

• Mercury content in the waste-derived fuels varies within a very wide range. • Co-combustion of waste-derived fuels may result in exceeding the emission limits. • Mercury content of alternative fuels should be strictly controlled. • Appropriate waste management enable the production fuels with suitable Hg content. The progressive decarbonisation of industry is leading to a reduction in coal consumption and the substitution for coal with other types of fuels, including waste-derived alternative fuels. These fuels are characterised by high variation in the content of highly toxic mercury. Co-combustion with coal can cause significant emissions, exceeding mercury emission limits. Various alternative fuels (refuse-derived fuel (RDF), waste paper, textiles, plastics, film, tires and their char, and sewage sludge) were examined for mercury content. The mercury content in analysed alternative fuels ranged from 0.4 to 92.0 µg Hg/MJ, with an average of 17.7 µg Hg/MJ. The fuels with the highest mercury content were RDFs (2.0–79.3 µg Hg/MJ) and sewage sludge (42.3–92.0 µg Hg/MJ). An acceptable amount of RDF added to hard coal which would remain within the emission limits was estimated to be 9–24% of the chemical energy in the blend. For sewage sludge, this amount was estimated to be 5–13%. For brown coal, with a much higher mercury content than hard coal, co-combustion with alternative fuels has a positive effect on reducing mercury emissions. It is possible to meet the mercury emission limits with a 95% contribution of the chemical energy coming from RDF. The blending of various types of waste supported by mild pyrolysis of high-mercury waste allows alternative fuels with relatively low mercury content to be produced. Such fuels may contribute a reduction in mercury emissions from coal-fired power plants in Poland. [ABSTRACT FROM AUTHOR]

• The hybrid mode of public service delivery poses governance problems. • The paper explores these problems in the context of waste management. • The authors conducted an in-depth qualitative study of Znojmo municipality. • The hybrid delivery of waste management is found to be successful. In the Western hemisphere, the hybridity of public service delivery is widely acknowledged to generate governance challenges arising from the mutual contestation of the competing institutional logics, such as those of the public and the private for-profit sector. The present paper explores these challenges by means of an in-depth qualitative case study of the waste management service delivery in the municipality of Znojmo, Czech Republic. Encompassing structured interviews of stakeholders and desk research, the case study was aimed at understanding the strengths and weaknesses of waste management hybridity, as well as the impact of hybridity on the relationship between innovativeness and accountability. The overall finding is that the engagement of the private for-profit sector does make this service delivery more innovative, but the useful impact of innovativeness is maximized through a hybrid arrangement. The key benefit of the hybrid arrangement is the stable intersectoral partnership allowing comprehensive control of the waste management service delivery. This benefit possibly rests on the accountability of the hybrid arrangement running on political rather than purely economic lines. Another finding was that the profit maximizing imperative was felt to constrain potential innovation, an outcome that could be prevented by the engagement of the municipality. At the same time, the hybrid mode of waste management service delivery in Znojmo is by no means free of governance challenges, such as the occasional lack of transparency and communication difficulties and disagreements among stakeholders. [ABSTRACT FROM AUTHOR]

• Origins of Al, Ca, Fe, Si, Ti, Mg, S, Na, K, and P are discussed using literature. • Ash contents and compositions of sorted SRF fractions are determined. • Contributions of material fractions to the recyclable share of SRF is investigated. • The main SRF fraction recycled in the cement kiln is the fine fraction. • The cement industry therefore offers a way to complement conventional recycling. Solid recovered fuel (SRF) ash consists of element oxides, which are valuable materials for cement manufacturers. When SRF is co-processed in the cement industry, its mineral content is incorporated into the clinker. Therefore, from a technical perspective, SRF ash is recycled. However, since recycling processes for materials that may be present in SRF exist, and since recycling goals are defined for different waste types, understanding the origin of these ash constituents and the contribution of different materials to the Recycling-index (R-index, i.e., the material-recyclable share of SRF) is important. In this work, the origins of Al, Ca, Fe, Si, Ti, Mg, Na, K, S, and P were first reviewed. Subsequently, ten SRF samples were sorted, and the ash content and composition of the sorting fractions (e.g., <10 mm, plastics, paper&cardboard) determined. Additionally, selected samples of polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), polyvinyl chloride (PVC), liquid packaging board (LPB), wood, and paper&cardboard (P&C) extracted from SRF were investigated. The results demonstrated that the materials that contributed most of the valuable oxides and ash content, and thereby to the R-index of SRF, are mixed or composite fractions, for example, the fine fraction, composites, and the sorting residues. Except for the composite LPB, no other material recovery options exist for most of these fractions. For this reason, the recycling of mixed and soiled materials or residues in the cement industry may be considered a complementary option to existing recycling processes. [ABSTRACT FROM AUTHOR]

• Cold gas efficiency of 80% for gasification of a plastic reject from recycled paper. • HCl reduction >98% with simple quench and two-stage combustion. • Gasification reduced dioxin emissions. • Automotive shredder residue fly ash = potential zinc concentrate for recycling. Oxygen blown high-temperature gasification constitutes an opportunity for chemical recycling of plastic wastes. This article summarizes the results from comparative tests of combustion and gasification of two complex plastic wastes: a plastic reject (PR) from processing recycled paper and an automotive shredder residue (ASR). Calculated gasification efficiencies corresponded to about 80% and 60%, respectively. Gasification resulted in lower yields of polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD/F) compared to direct combustion. A two-stage process, including gasification followed by syngas combustion, reduced the emissions of HCl and PCDD/F in the flue gas to <1.4% and <0.2%, respectively, compared to the levels from direct combustion of the PR feedstock. Most of the PCDD/F (>99%) was captured along with particulate matter (soot) during gasification. The contribution to the toxic concentration of PCDD/F was mainly from the PCDF congeners. Fly ash particulate matter from ASR combustion contained a significant proportion of zinc, which thus constitutes a great potential for use in zinc recycling. [ABSTRACT FROM AUTHOR]

In the USA, local governments have the primary responsibility to manage MSW. However, local governments lack the authority to explicitly shift costs or responsibility back onto the producer for specific problem wastes. A particularly problematic waste for local governments is the single-use plastic bag. In 2014, in the USA, 103.465 billion single-use plastic shopping bags were consumed. Because of their extremely low recyclability rate, plastic bags remain a significant source of land-based litter and marine debris and impair stormwater management systems. They also reduce the effectiveness of automated recycling systems. In response, local governments increasingly have adopted a variety of measures specifically intended to reduce the store-level consumption of single-use shopping bags in 5 major categories: bans, imposition of fees and taxes, establishing minimum product design of bags, requiring consumer education, and mandating retailer take-back programs. As of September 2017, there were 271 local governments in the USA with plastic bag ordinances covering 9.7% of the nation’s population. The majority (95%) of the ordinances is a ban on single-use plastic bags; 56.9% of these bans also include a mandatory fee on paper and/or reusable bags. For the fee-based ordinances, the mode is $0.10 per bag; every tax/fee ordinance allows retailers to retain some or all the collected fee. As local governments continue to increase their actions on plastic bags, 11 states have enacted laws to prohibit local governments from regulating single-use plastic bags. Because of the success with single-use bags, local governments are also enacting similar ordinances on single-use expanded polystyrene consumer products and other single-use plastic products. [ABSTRACT FROM AUTHOR]

• The shared and non-shared collection service systems are evaluated and compared. • The spatiotemporal characteristics of multiple stakeholders are considered. • A mixed-integer optimization model is established. • The shared service system is superior in economic and environmental implication. • The expansion of storage space is required to meet the future processing demand. One of the impending consequences of the rapid penetration of electric vehicles (EVs) is that a substantial amount of expired EV batteries will present an increasing waste collection and management problem, particularly in the urban context. Motivated by a lack of research on this issue, this paper comprehensively evaluates the relative benefits of shared versus non-shared collection systems, where the service outlets are not exclusive to specified automakers. Using a mixed-integer optimization model, the analysis features spatiotemporal and multiple stakeholder complexities. Based on the historical monthly EV sales data from 2016 to 2021, a representative case study of Beijing, China is conducted, including 16 district centers, 32 major automobile manufacturers, 153 collection service outlets and 4 disposal centers. The results show that a shared collection service system leads to higher profitability, higher collection rates, increased environmental benefits and improved facility utilization. Consequently, this research contributes to supply chain liberalization to foster the efficient waste management of EV batteries. With a further model extension, it can also provide decision support for the policy-making of more countries. [ABSTRACT FROM AUTHOR]

• Use of a new tool to assess waste management systems through a stage concept. • Holistic approach can evaluate 54 waste related system sub-components. • Identification of Circular Economy potentials for the city of Marrakech (Morocco). • Applicability proofed for waste management systems of the Global South. • Derivation of 33 recommendations for action to make Marrakech more circular. Waste management is essential for the safety and wellbeing of any society; it also helps to tackle global problems, such as climate change and resource scarcity. To support the evolution of waste management systems (WMSs) towards a circular economy (CE), assessment methods are applied. This paper shows, using the case of Marrakech (Morocco), how a novel holistic approach called WMS development stage concept (WMS-DSC) is applied to assess WMSs and determine measures promoting a CE. The approach enables a simplified derivation of measures that are useful to municipal decision makers and consists of five stages; stage 1 is equal to a WMS lacking essential WM elements and stage 5 describes a functioning CE. The approach was specifically designed to be transferable to other Global South cities through the categorization into these universal stages. The results from the WMS-DSC show that components related to energy recovery and waste recycling are classified in stage 1. For the latter, a slight development towards stage 2 can be assumed due to the planned activities in Marrakech. The components "collection and transport" and "prevention and reuse" are mainly in stage 2. Nevertheless, the components "governance", "sector and market" and "waste disposal" are assigned to stages 2 and 3 with a stronger trend towards stage 4. The results show that in Marrakech and Morocco, CE is still in its infancy, and with this current state, it is hard to achieve. However, 33 measures were determined to improve the WMS of Marrakech and promote a CE. [ABSTRACT FROM AUTHOR]

• Pavement biomass materials are divided into bio-oil, bio-fiber, bio-filler. • Pavement biomass materials from source to application were reviewed. • Composite modification can increase the content and utilization of bio-oil. • The latest performance research results of road biomass materials were compared. T o cope with the global climate crisis and assist in achieving the carbon neutrality, the use of biomass materials to fully or partially replace petroleum-based products and unrenewable resources is expected to become a widespread solution. Based on the analysis of the existing literature, this paper firstly classified biomass materials with potential application prospects in pavement engineering according to their application and summarized their respective preparation methods and characteristics. The pavement performance of asphalt mixtures with biomass materials was analyzed and summarized, and the economic and environmental benefits of bio-asphalt binder were evaluated. The analysis shows that pavement biomass materials with potential for practical application can be divided into three categories: bio-oil, bio-fiber, and bio-filler. Adding bio-oil to modify or extend the virgin asphalt binder can mostly improve the low temperature performance of asphalt binder. Adding styrene-butadienestyrene (SBS) or other preferable bio-components for composite modification will have a further improved effect. Most of the asphalt mixtures prepared by using bio-oil modified asphalt binders have improved the low temperature crack resistance and fatigue resistance of asphalt mixtures, but the high temperature stability and moisture resistance may decrease. As a rejuvenator, most bio-oils can restore the high and low temperature performance of aged asphalt and recycled asphalt mixture, and improve fatigue resistance. Adding bio-fiber could significantly improve the high temperature stability, low temperature crack resistance and moisture resistance of asphalt mixtures. Biochar as a bio-filler can slow down the asphalt aging process and some other bio-fillers can improve the high temperature stability and fatigue resistance of asphalt binders. Through calculation, it is found that the cost performance of bio-asphalt has the ability to surpass conventional asphalt and has economic benefits. The use of biomass materials for pavements not only reduces pollutants, but also reduces the dependence on petroleum-based products. It has significant environmental benefits and development potential. [ABSTRACT FROM AUTHOR]

• BSFL biodiesel shows lesser environmental impacts than other types of biodiesel. • BSFL valorization has 100x lesser global warming potential than sludge landfilling. • BSFL lipid content is the most sensitive factor that affects the LCA outcomes. • Sludge pre-treatment inflicts the most impact on BSFL biodiesel production. More energy is needed nowadays due to global population growth. Concurrently, sewage sludge generation has also increased steadily stemming from the inevitable urbanization. As such, black soldier fly larvae (BSFL) can be potentially deployed to solve both issues. This paper investigates the environmental sustainability of biodiesel production derived from sludge-fed BSFL feedstock. A cradle-to-gate life cycle assessment (LCA) was performed through SimaPro software utilizing the ReCiPe 2016 Midpoint (H) and Endpoint (H) methods. The entire LCA covered 3 main stages, including the thermal pre-treatment of sludge, BSFL rearing and processing, and lastly lipid extraction and biodiesel production. LCA showed that the sludge pre-treatment stage had the highest environmental impact, while BSFL rearing and processing had the least due to the suitable geographical climate. Electricity usage during the pre-treatment stage was the main contributing component, followed by chemical usage during biodiesel production. After normalizing, it was observed that land occupation, marine ecotoxicity, freshwater ecotoxicity and freshwater eutrophication were more impactful than the commonly studied global warming potential (GWP). Lipid content and biodiesel conversion efficiency were determined as the sensitive factors which could influence the LCA outcome. In comparison with other types of biodiesel, BSFL biodiesel had a milder impact in terms of climate change, land occupation, terrestrial acidification, marine and freshwater eutrophication. Furthermore, this biological reduction of sludge through BSFL valorization avoided sludge landfilling, which reduced up to 100 times GWP. Therefore, sludge-fed BSFL biodiesel production is an environmentally-sound and highly potential solution that should be investigated comprehensively. [ABSTRACT FROM AUTHOR]

• Food categories most wasted in Italy are fruit, vegetables, bread, milk and yogurt. • Larger town areas, 1 member families, and who have a low income wasted more. • Retired people and families with children wasted less. • This assessment poses the basis for a surveillance system on food waste in Italy. • Educational campaigns for specific target groups should be developed. In the present paper, the results of the first comparative assessment of household food waste in Italy are reported with a timeframe of three years coupled with an evaluation of seasonality effects. To pursue the aim of Sustainable Development Goal 12.3 to halve consumer food waste by 2030, the Italian Observatory on Food Surplus, Recovery and Waste carried out two surveys in 2021 (July and November) to characterize household food waste and to evaluate the seasonality effects. Data were collected with a validated questionnaire. For monitoring purposes, data collected in July 2021 were compared with those collected in July 2018. In three years, waste increased from 187.2 to 203.8 g per capita per week (p = 0.00). Fresh foods such as fruits and vegetables, bread, milk, yogurt, and non-alcoholic beverages, were the most wasted. In July the level of waste was higher for fruit (p = 0.00) while in November was higher for potato products (p = 0.04), pasta (p = 0.00), rice (p = 0.04), legumes (p = 0.01), and soups (p = 0.04). Data collected in July 2021 showed that retired people (p = 0.04), families with children (p = 0.01), particularly young children (9–13 years old) (p = 0.02), wasted less while who live in large town areas (p = 0.00), people with self-perceived limited monetary resources (p = 0.01) and mono-component families (p = 0.00) wasted more. The findings of the present work showed that there are specific population groups that wasted more with a gap between the intentions and the actions. The present data have a particular value posing the roots for the establishment of a food waste surveillance system in Italy. [ABSTRACT FROM AUTHOR]

• A special design of new berm reinforced with geotextile layers is reported. • Field tests conduct to show the performance of the berm with special design method. • Results explore the failure mechanism of the berm with special design method. This paper reports a case study of an extension design of an existing municipal solid waste (MSW) earth berm in Guangzhou, China. The berm has limited space for extension and was constructed during a rainy season. Due to the space constraint, the extended berm was designed with a steep slope 1.1 horizontal to 1.0 vertical (1.1 H :1.0 V). Due to the rainy season, the new extended earth berm was built with a mix of gravel and sandy clay (i.e. V gravel / V clay = 50:50). To make the new berm design satisfies the stability requirement, it has been reinforced with geotextile layers within the berm and piles at the toe of the berm. A 2D finite-element analysis has been conducted to demonstrate the rationality of the design. The performance of the new berm was monitored using field sensors, which include the vertical and lateral displacements of the berm, vertical earth pressure of the berm, and tensile strain of the geotextile layers during and after the berm construction. Numerical and field tests results show that the failure surface appears along the interface between the old berm and the horizonal displacements are mainly observed in the new berm. The results of this study proven that a steep slope berm with geotextiles reinforcement can resistant the load from extended MSW landfill, which can provide a guidance for the design and construction of the extension of MSW landfill. [ABSTRACT FROM AUTHOR]

• Monitor settlement of landfill cells with different ages using GNSS. • Settlement of a single waste lift is monitored by settlement profilers. • Effects of biodegradation on geotechnical properties of MSWs are considered. • Predicted settlement well fits that from experimental bioreactors and landfills. This paper presents the development of a new settlement model to predict the long-term settlement of municipal solid wastes (MSWs). The total settlement of the MSWs results from the direct loss of solids due to decomposition and compression due to stress variation induced by loss of solids, flow of gas and liquid and mechanical creep. The geotechnical properties of MSWs are considered as functions of degrees of biodegradation (DOB). To validate the model, two settlement profilers (2.5 years) and three geodetic monitoring networks (2 years) were installed at Mugga Lane Landfill, ACT, Australia to monitor the settlement of an MSW lift and three closed landfill cells, respectively. The settlement rates of the landfill cells with the ages of 7, 8, 14, and 8, 9 and 15 years are 0.53, 0.35, 0.06 and 0.46, 0.36, 0.05 mm/day, respectively. In addition, 5 large scale and 3 small scale bioreactors were set up in the field and laboratory to address the long-term physical, mechanical and biochemical behaviours of the MSWs under different stress levels. The predicted settlement is compared to the test results from the bioreactors, in-situ monitoring data and the settlement predicted using an existing model, which has been improved by coupling the geotechnical properties of MSWs with DOBs. The predicted settlement using the proposed model well fits the test results and monitoring data. The settlement strain is predicted to be 28.2 % during the filling stage of the landfill and 5.9 % in 5 years after the closure. [ABSTRACT FROM AUTHOR]

• Non-utilitarian factors shape individual's WTP for WMS improvements. • Environmental values are key predictors of WTP for improved WMS. • Preferences for WMS are determined by environmental and local contexts. • Socioeconomics' impact on WMS preferences through environmental values is weak. • Effective WMS policy making must be context-specific. Efficient Waste Management Systems (WMS) depend on citizens' willingness to sort waste and to cooperate for its improved provision. Thus, it is essential to understand what attributes individuals value the most and what drives WMS preference heterogeneity. In this paper, we investigate how individuals evaluate WMS attributes (e.g., the number of waste sorting categories, the introduction of textile sorting, and the frequency of collection per week) and how the local contexts, socioeconomics, and environmental values shape their preferences. For this purpose, we conducted a discrete choice experiment on a sample representative of the Italian population interviewed through an online panel survey. We collected information on individual's preferences for WMS attributes, environmental awareness, and socioeconomic characteristics. We analyzed the data using hybrid mixed choice models, which allowed us to integrate environmental awareness values into willingness to pay estimations. We found that individuals are willing to pay for waste sorting, even if this implies more effort on their part and increased storage space. In addition, we found that the extent to which individuals support WMS improvements strongly depends on their environmental values, experiences (which are shaped by their local context), and socioeconomic factors. Our results suggest that to increase recycling rates and citizen satisfaction, there is a need for context-specific WMS designs that acknowledge the observed heterogeneity of preferences. [ABSTRACT FROM AUTHOR]

Highlights: [•] Anaerobic degradation parameters of nut waste were different from other food waste. [•] Paper should be subdivided into degradable paper and refractory paper. [•] Garden waste should be divided into grass and leaves, and branches. [•] Wood should not be subdivided according to CSF. [ABSTRACT FROM AUTHOR]

• Informal sector is an integral part of waste collection and recycling system. • The informal sector should be integrated into formal waste management system. • Causal loop diagrams are developed for waste collection and recycling system. • It can be used to decide leverage points for policy implementation. • Promoting informal sector is reasonable to diversify income sources of poor people. Although the informal sector of waste collection has an important role in income diversification for the poor and contribution to waste recycling, this sector is still not recognised in any government official policies and is usually underestimated in the Mekong Delta of Vietnam. This paper employs a systems thinking approach to analyse the crucial roles of the informal sector in solid waste management (SWM) system in Vietnam. From a circular economy viewpoint, the flow diagram was built for the first time, which could integrate the actors and activities of the informal sector into a wider SWM system in Vietnam. The map focuses on analysing the contributions and activities of the informal sector, focusing on its roles and impacts on the recycling system. This paper then employed the systems thinking approach to further analyse the systematic problem of the informal sector. The analysis builds on the field survey including elements and key driving forces of the systems with 36 scrap dealers, 127 scrap buyers, and 760 households and in-depth interviews with experts in the Mekong Delta region, Vietnam. Based on the practices and experience in waste-related activities of informal sector, this sector should be integrated into the general waste management process. With the relevance of informal systems, the authorities could establish an effective waste recycling system, and improve the livelihoods and working conditions of those involved, especially the poor. [ABSTRACT FROM AUTHOR]

• Waste emissions scenarios are modelled with the rapid assessment software CCAC SWEET. • HIA for PM 2.5 and application of publicly available tool WHO AirQ+. • 94% reduction of long-term mortality due to reductions in PM 2.5 emissions in 2030. • A detailed analysis of the current situation provides suggestions for waste management policies. Despite the clear link between air pollution and health, research to investigate the relationship between municipal solid waste management and air pollution and health has not been prioritized. Such research may generate scientific information that would help reduce population exposure to air pollutants. This paper examines the case study of Accra in Ghana, a city dealing with serious waste management problems. The paper proposes a methodology to estimate the impact of waste management on urban air pollution and health. The analysis is described in the following four steps: (1) collecting data on the waste sector; (2) modeling the emissions arising from waste management; (3) transforming emissions to concentration values and (4) estimating the burdens on health. The assessment has been conducted using the CCAC SWEET tool and WHO AirQ+. The method presented can be used in different locations, depending on data availability, when analyzing the impact of and potential changes to waste sector policies. The results of this health impact assessment indicate that, based on the emissions of PM 2.5 from the waste sector in Accra, a change from the business-as-usual to more sustainable options would reduce air pollutants emissions and avert 120 premature deaths in 2030. Levels of air pollution in Accra are significant and interventions to reduce PM 2.5 exposure should be promoted. The detailed analysis of the current situation provides suggestions for waste management policies in terms of impacts on health and ideas to reconsider the waste policies in Accra. [ABSTRACT FROM AUTHOR]

• Process analysis was performed for the biodiesel production from waste cooking oil. • Analysis was performed for an innovative process based on hydrodynamic cavitation. • Several scenarios were presented which take into account the type of the feedstock. • The replacement of the virgin oil with waste oil reduces the operative costs. • Further reduction of the costs can be obtained by using the innovative process. Biodiesel production calls for innovative solutions to turn into a competitive process with a reduced environmental impact. One of the process bottlenecks stands in the immiscibility of oil and alcohol as raw materials, so mixing process largely impacts the overall process cost. This process step, if carried out by using hydrodynamic cavitation, has the possibility to become a benchmark for large scale applications. In this paper a process analysis of biodiesel production scheme is developed starting from two different feedstocks, virgin oil and waste cooking oil. At the first the traditional process scheme has been simulated, in a second simulation, the reactor for the biodiesel production is interchanged with a hydrodynamic cavitation reactor. In the paper, the comparison between the traditional and innovative process by using life cycle costing approach has been presented, thus providing indications for industrial technological implementation coming from a professional tool for process analysis. It is worth noting that the introduction of hydrodynamic cavitation reduces of about 40% the energy consumption with respect to the traditional process. As regards the total treatment costs, when using virgin oil as feedstock, they were in the range 820–830 €/t (innovative and traditional process, respectively); while starting from waste cooking oil the costs decreased of about 60%, down to 290–300 €/t (innovative and traditional process, respectively). [ABSTRACT FROM AUTHOR]

• This paper covers the coffee production process, with emphasis on by-products. • The chemical composition of generated by-products was reviewed. • The application of coffee industry by-products in polymer technology was reviewed. • Potential benefits of coffee industry by-products recycling were highlighted. • Coffee industry by-products may act as antioxidants for polymeric materials. Coffee is one of the most popular beverages in the world, and its popularity is continuously growing, which can be expressed by almost doubling production over the last three decades. Cultivation, processing, roasting, and brewing coffee are known for many years. These processes generate significant amounts of by-products since coffee bean stands for around 50% of the coffee cherry. Therefore, considering the current pro-ecological trends, it is essential to develop the utilization methods for the other 50% of the coffee cherry. Among the possibilities, much attention is drawn to polymer chemistry and technology. This industry branch may efficiently consume different types of lignocellulosic materials to use them as fillers for polymer composites or as intermediate sources of particular chemical compounds. Moreover, due to their chemical composition, coffee industry by-products may be used as additives modifying the oxidation resistance, antimicrobial, or antifungal properties of polymeric materials. These issues should be considered especially important in the case of biodegradable polymers, whose popularity is growing over the last years. This paper summarizes the literature reports related to the generation and composition of the coffee industry by-products, as well as the attempts of their incorporation into polymer technology. Moreover, potential directions of research based on the possibilities offered by the coffee industry by-products are presented. [ABSTRACT FROM AUTHOR]

• It improves the comprehension of UHSWM from the triple bottom line perspective. • The paper offers opportunities to improve UHSWM in developing countries. • The three pillars of the German solid WM system support the opportunities revealed. • "Wasteaware" benchmarks and process flow diagrams are used for ISWM comparison. • Matrix quantification score was 98% for Münster (Germany) and 50% for Macaé (Brazil). Countries worldwide strive to improve their urban household solid waste management (UHSWM) practices. While developed countries like Germany have achieved good results with different UHSWM initiatives, developing countries still struggle to be effective with their waste management (WM) policies. With an interest in learning from the German experience, this paper provides a cross-case analysis between a German and a Brazilian city that can be of practical relevance to improving UHSWM in developing countries. The paper uses "process flow diagram" (PFD) and "wasteaware benchmark indicators" for integrated sustainable waste management (ISWM). Both methods confirmed the German city as a benchmark and attested the inefficiency of the Brazilian UHSWM. The total maximum score weightage percentage of the matrix quantification difference was significant, 98% against 50%. Findings highlight viable solutions based on the three pillars of the German solid WM system: clear laws, regular public campaigns, and fee methodology. The formalization and improvement of Brazilian UHSWM require better governance to obtain additional investments. Herein, the application of the Green Dot methodology, sponsored by industry and consumers in Germany, would enable an increase of up to 318% of the values received by a typical Brazilian cooperative. This additional investment can empower a sustainable solution where the population could opt to work with recycling, either as a formal employee or as a formal entrepreneur, shedding more light on the social pillar of the triple bottom line. Moreover, it can enable improvements in technologies, and on regular public campaigns to increase education in important sustainable matters. [ABSTRACT FROM AUTHOR]

• Over 11,000 particles from commercial waste are characterised with 13 descriptors. • 5 particle size classes and 5 material fractions are considered in the investigation. • A PLS regression model is used to predict the particle size class based on a 2D-image. • First results for sensor-based screening analysis of singlified objects are presented. To optimize output streams in mechanical waste treatment plants dynamic particle size control is a promising approach. In addition to relevant actuators – such as an adjustable shredder gap width – this also requires technology for online and real-time measurements of the particle size distribution. The paper at hand presents a model in MATLAB® which extracts information about several geometric descriptors – such as diameters, lengths, areas, shape factors – from 2D images of individual particles taken by RGB cameras of pre-shredded, solid, mixed commercial waste and processes this data in a multivariate regression model using the Partial Least Squares Regression (PLSR) to predict the particle size class of each particle according to a drum screen. The investigated materials in this work are lightweight fraction, plastics, wood, paper-cardboard and residual fraction. The particle sizes are divided into classes defined by the screen cuts (in mm) 80, 60, 40, 20 and 10. The results show assignment reliability for certain materials of over 80%. Furthermore, when considering the results for determining a complete particle size distribution – for an exemplary real waste – the accuracy of the model is as good as 99% for the materials wood, 3D-plastics and residual fraction for each particle size class respectively as assignment errors partially compensate each other. [ABSTRACT FROM AUTHOR]

• All three discussed recycling types are profitable under current policy measures. • Chicken manure is more cost-effective for composting. • Pig manure is more cost-effective for energy recycling. • Without FITs, biogas power generation of livestock manure is not profitable. • RDF of rice straw is the most cost-effective. Agricultural waste can be recycled in different ways. Cost-effectiveness is important information for investment decision-making of enterprises and policy-making of government to choose a profitable way to recycle agricultural waste. Therefore, this paper aims to present a cost-benefit analysis to assess and compare the cost-effectiveness between feasible recycling methods, and further propose cost-effective ways for recycling agricultural waste in Taiwan. Three recycling types of agricultural wastes, namely, composting, biogas power generation and biomass fuel are selected for cost-benefit analysis based on related regulations and policy supports of agricultural waste management in Taiwan. Primary data collected by sampling surveys conducted in 2018 supplemented by secondary data from national statistics are used for this study. Study results show that all three recycling types of agricultural wastes discussed in this study are profitable under corresponding economic conditions in 2018 with benefit/cost ratio greater than 1 and positive net present value; as expected, the cost-effectiveness of agricultural waste recycling varies depending on the recycling types, composition of input materials, and economic scales. Mixing chicken manure with other agricultural wastes for composting and using rice straw to make biomass fuel rods are estimated to have higher cost-effectiveness; livestock farms with small farming scale have relatively low biogas energy recovery efficiency; the cost-effectiveness of biogas power generation highly depends on fixed-in tariffs (FITs). Results imply that policy support for establishing co-processing centers of agricultural waste and differentiated FITs would be good measures to stimulate recycling efficiency of agricultural waste in Taiwan. [ABSTRACT FROM AUTHOR]

• Around 1.4 million sales transaction data of 25 years were used in this study. • In 1991–2015, sale-related renovation waste could reach up to 4.46 MT. • A self-reporting levy is proposed to refine the waste and policing cost estimate. • More informed market forces may help address latent renovation-inducing factors. Using data of 1.4 million non-aggregate, publicly available, private residential property resale transactions for Hong Kong from 1991 to 2015, this paper addresses a public policy question raised by Demsetz from a Coasian angle. It estimates the impact of a less explored but ecologically problematic realm of renovation waste upon change of ownership of property units in a highly commodified property market. The estimate shows the extent and possibly high cost of the government in addressing negative externalities. Informed by the findings, this paper puts forward the recommendation of a prepaid lump sum waste monitoring levy, which is reimbursable upon self-reporting of waste generation. The collected information, when made open to the public, may help market forces to address poor building quality which causes legitimate major renovations and encourage better workmanship for future edifices. [ABSTRACT FROM AUTHOR]

• Poultry carcass parts were stabilized during 30 days of thermophilic composting. • Mass loss was nearly 100% for hearts and livers and 30–40% for skin parts. • Dimethyl disulfide (DMDS) and trisulfide (DMTS) contributed 81–88% of VOC fluxes. • Odor was dominated by methanethiol, DMDS, benzaldehyde, pentanoic acid and NH 3. • DMDS/DMTS ratio above 10–13 may indicate sufficient carcass stabilization. Short-term on-site composting of poultry carcasses and broiler litter (BL) is considered as a feasible technology for pathogen elimination during events of mass mortality in poultry houses. However, factors related to mass losses and physical transformation of the poultry carcass, and associated emissions of volatile organic compounds (VOCs) and odors, have not been thoroughly evaluated. This study aims to characterize the degradation of separated carcass parts co-composted with BL and the associated air emissions during 30 days of enclosed composting at 50 °C with constant aeration. The study was carried out in lab-scale simulators using five mixtures containing feathers, rib bones, skins, breast muscles, and hearts and livers, prepared at a 1:2 volumetric ratio (carcass:BL). Dry mass losses reached 59.5, 41.1, 60.8 and 103.5% (based on weight) or 48.4, 29.6, 49.7, and 94.8% (based on CO 2 -C and NH 3 -N emissions), for rib bones, skins, breast muscles, and hearts and livers, respectively. Visually, most of the carcass parts were degraded, and the typical carcass odor had disappeared by the end of the 30 days. Out of 24 VOCs, dimethyl disulfide (DMDS) and dimethyl trisulfide (DMTS) contributed 80.7–88.3% of the total VOC flux, considering the partial contribution of each part to the emissions involved with the whole carcass. DMDS, DMTS, benzaldehyde, methanethiol, pentanoic acid, and NH 3 , contributed 90.5–97.9% of the odor activity values during composting. DMDS/DMTS ratio is suggested as a potential biomarker of stabilization and readiness of the compost for transportation toward further treatment or safe burial. [ABSTRACT FROM AUTHOR]

• This paper investigated 10 different Chinese cities. • It investigated current status of C&D waste management in China. • Eight major challenges limiting the promotion of waste management were found. • Recommendations were provided for the policy makers. China produced a large amount of construction and demolition (C&D) waste, owing to the rapid development of construction industry. Although a set of policies and regulations are being drafted in China for promoting C&D waste recycling, execution of these policies in practice seems to be far from effective. Currently, approximately 75% of Chinese cities are still surrounded by large volumes of C&D waste. Therefore, identification of challenges in the development of C&D waste management, specially recycling, is essential. This paper employs site visits to 10 recycling plants in 10 Chinese cities (Shanghai, Hangzhou, Suzhou, Chongqing, Chengdu, Xi'an, Changsha, Shenzhen, Nanjing, and Zhoukou) and interviews with 25 industry practitioners for examining the challenges. Eight challenges are identified: (1) unstable source of C&D waste for recycling, (2) absence of subsidies for recycling activities and high cost for land use, (3) insufficient attention paid to design for waste minimisation, (4) absence of regulations on on-site sorting, (5) unregulated landfill activities, (6) a lack of coordination among different government administration departments, (7) a lack of accurate estimation of waste quantity and distribution, and (8) a lack of an effective waste tracing system. Recommendations to address these challenges are presented. The results of this study are expected to aid policy makers in formulation of proper C&D waste management in China and provide a useful reference for researchers who are interested in C&D waste recycling industry. [ABSTRACT FROM AUTHOR]

• LCA provides a much improved holistic view of waste management. • LCA helps understanding waste flows and potential environmental impacts. • There is still a need to use LCA models in integrated waste management. • LCA is expected to play a role in six areas of waste management in the future. Life cycle assessment (LCA) has been used in waste management for the last two decades and hundreds of journal papers have been published. The use of LCA in waste management has provided a much-improved holistic view of waste management including waste flows and potential environmental impacts. Although much knowledge has been obtained from LCA studies, there is still a need to use LCA models in integrated waste management. This paper describes six areas where LCA is expected to play a role in waste management in the future: 1) understanding an existing waste management system; 2) improving existing waste management systems; 3) comparing alternative technologies/ technology performance; 4) technology development/prospective technologies; 5) policy development/strategic development; and 6) reporting. Illustrative examples are provided for each application area. [ABSTRACT FROM AUTHOR]

The public awareness of the quality of environment stimulates the endeavor to safe polymeric materials and their degradation products. The aim of the forensic engineering case study presented in this paper is to evaluate the aging process of commercial oxo-degradable polyethylene bag under real industrial composting conditions and in distilled water at 70 °C, for comparison. Partial degradation of the investigated material was monitored by changes in molecular weight, thermal properties and Keto Carbonyl Bond Index and Vinyl Bond Index, which were calculated from the FTIR spectra. The results indicate that such an oxo-degradable product offered in markets degrades slowly under industrial composting conditions. Even fragmentation is slow, and it is dubious that biological mineralization of this material would occur within a year under industrial composting conditions. The slow degradation and fragmentation is most likely due to partially crosslinking after long time of degradation, which results in the limitation of low molecular weight residues for assimilation. The work suggests that these materials should not be labeled as biodegradable, and should be further analyzed in order to avoid the spread of persistent artificial materials in nature. [ABSTRACT FROM AUTHOR]

Abstract: Commercial institutions have many factors to consider when implementing an effective recycling program. This study examined the effectiveness of three different types of recycling bins on recycling accuracy by determining the percent weight of recyclable material placed in the recycling bins, comparing the percent weight of recyclable material by type of container used, and examining whether a change in signage increased recycling accuracy. Data were collected over 6weeks totaling 30days from 3 different recycling bin types at a Midwest University medical center. Five bin locations for each bin type were used. Bags from these bins were collected, sorted into recyclable and non-recyclable material, and weighed. The percent recyclable material was calculated using these weights. Common contaminates found in the bins were napkins and paper towels, plastic food wrapping, plastic bags, and coffee cups. The results showed a significant difference in percent recyclable material between bin types and bin locations. Bin type 2 was found to have one bin location to be statistically different (p =0.048), which may have been due to lack of a trash bin next to the recycling bin in that location. Bin type 3 had significantly lower percent recyclable material (p <0.001), which may have been due to lack of a trash bin next to the recycling bin and increased contamination due to the combination of commingled and paper into one bag. There was no significant change in percent recyclable material in recycling bins post signage change. These results suggest a signage change may not be an effective way, when used alone, to increase recycling compliance and accuracy. This study showed two or three-compartment bins located next to a trash bin may be the best bin type for recycling accuracy. [Copyright &y& Elsevier]

Abstract: The reuse and recycling of waste materials are now sincerely considered to be an integral part of solid waste management in many parts of the world. In this context, a vast number of options ranging from small scale decentralized to larger scale centralized plants have been adopted. This study aimed at investigating the waste reuse schemes in Khulna city located in the southern part of Bangladesh and ranked third largest city in the country. The shops for reusable material (SRM) were mostly situated around railway, waterway, and truck station markets which provided easy transportation to further locations. For the reuses of waste materials and products, a chain system was found to collect reusable wastes under a total number of 310 identified SRM with 859 persons directly or indirectly involved in the scheme. This was a decentralized waste management system with self sufficient (autonomous) management. According to mass balance, about 38.52tonsd−1 solid wastes were reused in Khulna city area, accounting for 7.65% of the total generated wastes. This study revealed that apparently a silent, systematic, smooth, and clean reuse chain has been established in Khulna city area under private initiatives, whose sustainability was confirmed over the years in the country without any official or formal funds. However, proper adjustment between the higher and lower chain in the materials flow path, as well as personal hygiene training for the workers, would further improve the achievements of the established reuse scheme. [Copyright &y& Elsevier]

• Drying shrinkage of alkali-activated material (AAM) is related to mesopore volume. • Na 2 SO 4 crystals act as expansive agents and aggregates reducing drying shrinkage. • Air pollution-controlled residue (20 %) applied to AAM is safe for the environment. Recycling air pollution-controlled residues (APCR) generated from sewage sludge incinerators can be used for waste management, but the leaching of potentially toxic heavy metals from APCR poses environmental and human health issues. The present paper describes a procedure using APCR to produce alkali-activated materials and thereby realize their disposal. The effect of APCR on the compressive strength and drying shrinkage of the alkali-activated slag/glass powder was investigated. The pore structure characteristics were analyzed for clarifying its relationship with drying shrinkage. The results indicated that the drying shrinkage of the alkali-activated material was related to the mesopore volume. The drying shrinkage was slightly increased after the incorporation of the 10 % APCR, which was likely attributed to the high volume of mesopores compared to the 20 % APCR that lowered the drying shrinkage and compressive strength. This decrease in drying shrinkage was due to the recrystallization of sodium sulfate in the pore solution that can act as expansive agents and aggregates. The growth stress of the crystalline sodium sulfate within the matrix can offset the tension stress caused by the water loss. In addition, leaching studies using the SW-846 Method 1311 showed that recycling APCR into the alkali-activated system did not present a toxicity leaching risk or release unacceptable concentrations of heavy metals. The incorporation of waste APCR and waste glass can make AAMs a very promising and safe environmental technology. [ABSTRACT FROM AUTHOR]

[Display omitted] • A strategy for converting biowaste into sugars and biopesticides is evaluated at a prototype scale. • Bacillus thuringiensis biopesticide is produced from the solid residue after enzymatic hydrolysis of biowaste. • 1 kg of dry biowaste is converted into 338 g of sugars and 2.35 × 1011 Bacillus thuringiensis spores. • Effective pH control during SSF was achieved using high-buffering cosubstrates. • Microbial community analysis showed a selective effect during the fermentation process. Alternative production processes using waste are necessary to preserve non-renewable resources and prevent scarcity of materials for future generations. Biowaste, the organic fraction of municipal solid waste, is abundant and easily available. It can be fractionated into building blocks for which fermentative processes can be designed. By using solid-state fermentation, this paper proposes a method of valorizing biowaste's residual solid fraction after enzymatic hydrolysis. In a 22 L bioreactor, two digestates from anaerobic digestion processes were evaluated as cosubstrates to modify the acidic pH of the solid residue after enzymatic hydrolysis and promote the growth of the bacterial biopesticide producer Bacillus thuringiensis. Regardless of the cosubstrate used, the final microbial populations were similar indicating microbial specialization. The final product contained 4 × 108 spores per gram of dry matter and also crystal proteins of Bacillus thuringiensis var israelensis , which have insecticidal activity against pests. This method allows for the sustainable use of all materials liberated during the enzymatic hydrolysis of biowaste, including residual solids. [ABSTRACT FROM AUTHOR]