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The effects of synthetic fertilizer and nutrient leaching are causing serious problems impacting soil function and its fertility. Mitigation of nutrient leaching and use of chemical fertilizer is crucial as fertile land adds up sustainability to climate changes. Biochar produced from agricultural bio-waste and municipal solid waste has been used for crop production and when applied in combination with organic nutrients may support mitigation of nutrient loss and adverse effects of chemical fertilizers. Different types of biochar and their application for soil enhancement have been observed, pine needle and sewage sludge derived low-temperature biochar along with compost, organic fertilizer in the form of manure and microalgal biomass may interact with soil chemistry and plant growth to impact nutrient loss and compensate the hazardous effect of chemical fertilizer, but it has not been investigated yet. This present study elaborates application of sewage sludge and pine needle biochar produced at 400 °C in an application rate of 5 % w/w and 10 t h-1 in combination with compost, manure and microalgal biomasses of Closteriopsis acicularis (BM1) and Tetradesmus nygaardi (BM2) on the growth of Chickpea (Cicer arietinum) and Fenugreek (Trigonella foenum-graecum) crop assessed in a pot experiment over a two crop (Chickpea - Fenugreek) cycle in Pakistan. Results depict that the pine needle biochar with additives has increased plant height by 104.1 ± 2.76 cm and fresh biomass by 49.9 ± 1.02 g, buffered the soil pH to 6.5 for optimum growth of crops and enhance carbon retention by 36 %. This study highlights the valorization of sewage sludge and pine needle into biochar and the effect of biochar augmentation, its impact on soil nutrients and plant biomass enhancement. The greener approach also mitigates and helps in the sustainable management of solid wastes.

Rapid determination of moisture content plays an important role in guiding the recycling, treatment and disposal of solid waste, as the moisture content of solid waste directly affects the leachate generation, microbial activities, pollutants leaching and energy consumption during thermal treatment. Traditional moisture content measurement methods are time-consuming, cumbersome and destructive to samples. Therefore, a rapid and nondestructive method for determining the moisture content of solid waste has become a key technology. In this work, an attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and multiple machine learning methods was developed to predict the moisture content of multi-source solid waste (textile, paper, leather and wood waste). A combined model was proposed for moisture content regression prediction, and the applicability of 20 combinations of five spectral preprocessing methods and four regression algorithms were discussed to further improve the modeling accuracy. Furthermore, the prediction result based on the water-band spectra was compared with the prediction result based on the full-band spectra. The result showed that the combination model can efficiently predict the moisture content of multi-source solid waste, and the R

The occurrence of temperatures in municipal solid waste (MSW) landfills in excess of 55 °C is a problem that has gained much attention in the solid waste industry, both domestically and globally. Facilities which frequently experience such temperatures are termed Elevated Temperature Landfills (ETLFs). Ash, both MSW incinerator ash (MSWIA) and coal combustion ash (CCA), when co-disposed with unburned MSW, can provide constituents which are able to partake in abiotic exothermic reactions that may develop or sustain elevated temperatures. These reactions include hydration and carbonation, as well as the oxidation and corrosion of metals commonly found in ash. In this study, sixteen ash samples from across the U.S. were characterized by using X-ray diffraction (XRD), X-ray fluorescence (XRF), and scanning electron microscopy coupled with X-ray energy dispersive spectroscopy (SEM/XEDS) to identify complex mineral and glassy phases enriched in calcium, silicon, aluminum, and iron. The high-temperature incineration of MSW and coal feedstocks, along with weathering processes impacting these ashes, yield a heterogenous material capable of generating appreciable heat given the right conditions. Additionally, a simple model was developed and, using ash compositions obtained via XEDS, a value termed relative heat potential (RHP) was estimated for each sample. Results show that CCAs may be expected to generate roughly 15 % more heat than MSWIAs when deposited in landfills due to their greater aluminum content.

Soil-like material (SLM) mined from municipal solid waste (MSW) landfills can be used as nursery cultivation soil, landfill cover, and as a building material. However, SLM utilization is restrained by heavy metal (HM) contents whose speciation and migration are influenced by their dissolved organic matter (DOM) content. Therefore, the properties of aged refuse and the correlation between DOM and HM forms were studied using samples from different types of MSW landfills. The dominant components of aged refuse were SLM (18.80%-83.51%) and plastics (11.17%-65.51%). The moisture, organic matter, and pH ranged from 29.55% to 57.92%, 15.70%-57.68%, and 7.84-8.51, respectively. The Zn content was highest (455.48-1379.27 mg/kg) in the SLM, followed by Cu (96.29-428.90 mg/kg), Cr (49.10-236.21 mg/kg), Pb (53.52-222.71 mg/kg), and Ni (20.92-39.10 mg/kg). The SLM cannot be used for agriculture because the HM contamination exceeds the multiple of 0.07-7.99. Zinc in the acid-soluble state and reducible state had the highest mobility in SLM. However, Cu and Pb, mainly in the oxidizable state, and Cr and Ni, in the oxidizable and residual states, were relatively stable. In the sanitary and simple MSW landfills, the average proportion of protein-like materials decreased from 84.44% to 82.61% and from 65.58% to 55.94%, respectively, as the landfill depth increased. Both the acid-soluble and oxidizable HM states and all forms of Zn in the SLM were significantly positively correlated with tyrosine-like materials (r = 0.58*-0.87**). Protein-like materials may enhance the mobility of HMs.

The effects of sewage sludge phosphorus (P) content on heavy metal behavior during co-incineration of sewage sludge and municipal solid waste (MSW) were evaluated. Thermogravimetric differential thermal analysis revealed that MSW incineration was mainly caused by organic matter and fixed carbon, while sewage sludge incineration was caused by volatile matter. During co-incineration, the peak weight loss at 460 °C shifted to slightly higher temperatures and the sludge ratio increased, indicating that interaction effects during co-incineration delayed pyrolysis and polymer/fixed carbon incineration. The residual heavy metal ratios after mono-incineration of sewage sludge were higher than those after MSW mono-incineration. The Cl content of MSW (0.757%) was much higher than that of sewage sludge (0.068%), which resulted in the conversion of heavy metals into metal chlorides and then volatilized during MSW mono-incineration. A synergistic effect of co-incineration was evident for Cu, but not for lead (Pb) or cadmium (Cd). X-ray absorption fine structure (XAFS) measurement revealed that Cu in MSW ash was in the form of CuO(s), but was Cu

Clinical procedures in a Nuclear Medicine Department produce radioactive liquid and solid waste. Regarding waste release into the environment from an authorised hospital, it is mandatory to verify the compliance with European Directive 2013/59/EURATOM, adopted by the Italian Government via the Legislative Decree 101/2020.Different activity release pathways into the environment from Trieste Nuclear Medicine Department have been analysed: liquid waste from patients' excreta discharged by sewage treatment system into the sea, and atmospheric releases following solid waste incineration. Reference models, provided by NCRP and IAEA guidelines, have been implemented to assess the impact of the discharged radioactivity for coastal waters and atmospheric transport conditions. Finally, an accidental fire event occurring in Radiopharmacy Laboratories has been simulated by HotSpot software.Advanced screening models give an effective dose to population of 5.3 · 10The total annual effective doses estimated to representative person, due to both Nuclear Medicine authorised clinical practices and in case of an accidental fire event, are in compliance with regulatory stipulations provided by Directives.

A new co-processing mode of waste liquid from anaerobic fermentation of organic wastes and municipal solid waste incineration fly ash (MSWI-FA) dechlorination is reported in this paper. Taking acetic acid, the most common organic acid in anaerobic fermentation systems, as the representative of anaerobic fermentation organic acids, the improvement of the dechlorination effect and the mechanism of washing MSWI-FA with low concentrations of organic acid lotion were explored. The chlorine content of MSWI-FA was reduced to 0.82% after the optimal process washing pretreatment. Three anaerobic fermentation waste liquids (AFWLs) were used to verify that the chlorine content of MSWI-FA could be reduced to less than 1%, and the dechlorination effect of brewery wastewater, which reduced the chlorine content of MSWI-FA to 0.91%, was the best at this. The influence of the washing process on MSWI-FA pyrolysis was reflected in the whole process. The release of chloride decreased and the weight loss was mainly due to the release of CO

Mixed municipal solid waste (MSW) may be pre-treated in a mechanical-biological treatment (MBT) plant to produce an exiting stream with improved combustible characteristics. The process also produces a second waste stream, which is generally separated on a size basis by industrial sieving equipment. It contains fractions with a high moisture content such as residual food waste, soiled paper and cardboard, and small fragments of other materials. Samples of this stream, collected at an existing plant, were characterized and processed by hydrothermal carbonization (HTC) at laboratory scale, at various temperatures (180, 200 and 220 °C), reaction times (1, 4 and 8 h) and solid to water ratios (0.15 and 0.07). The primary energy balance, on a hypothetical industrial scale, was performed. In brief, the results confirmed that the produced hydrochar was a brittle, hydrophobic, solid carbonaceous product which gave a better combustion performance as the residence time of the HTC process was increased. Moreover, the dewaterability of the carbonized waste was greatly improved when compared to raw, wet samples. The results of the primary energy balance confirmed that the energy contained in the produced hydrochar was higher than the energy consumption for the process itself, under all the HTC working conditions. The energy consumed in the process was in the range of 40-70 % of the energy content of the produced hydrochar.

Microbes are the drivers for disposing of organic solid waste (OSW) during composting. Moreover, humus is a multipurpose biological macromolecule synthesized by microorganisms during composting. Here, we investigated the humification degree (HD), and the humus content was assessed in terms of the bacterial community. Microbial sequencing and bioinformatics approaches were combined to analyze the biological characteristics of 105 composting samples. The bacterial communities were useful indicators for making predictions and even correctly determined the categories of OSWs with 94% accuracy. Furthermore, the bacterial genera screened were designated as a bacterial code. The bacterial codes can also provide a better prediction of HD. Our results suggested that the bacteria code is a reliable biological method to assess HD effectively. Bacterial codes can be used as ecological and biological indicators to evaluate the quality of composting of different materials.

In Material Recovery Facilities (MRFs), recyclable municipal solid waste is turned into a precious commodity. However, effective recycling relies on effective waste sorting, which is still a challenge to sustainable development of our society. To help the operations improve and optimise their process, this paper describes PortiK, a solution for automatic waste analysis. Based on image analysis and object recognition, it allows for continuous, real-time, non-intrusive measurements of mass composition of waste streams. The end-to-end solution is detailed with all the steps necessary for the system to operate, from hardware specifications and data collection to supervisory information obtained by deep learning and statistical analysis. The overall system was tested and validated in an operational environment in a material recovery facility. PortiK monitored an aluminium can stream to estimate its purity. Aluminium cans were detected with 91.2% precision and 90.3% recall, respectively, resulting in an underestimation of the number of cans by less than 1%. Regarding contaminants (i.e. other types of waste), precision and recall were 80.2% and 78.4%, respectively, giving an 2.2% underestimation. Based on five sample analyses where pieces of waste were counted and weighed per batch, the detection results were used to estimate purity and its confidence level. The estimation error was calculated to be within ±7% after 5 minutes of monitoring and ±5% after 8 hours. These results have demonstrated the feasibility and the relevance of the proposed solution for online quality control of aluminium can stream.

There is an increasing awareness that effective waste management is essential for transitioning towards a circular economy and achieving sustainable development goals. Scholars have studied inter-municipal cooperation (IMC) as a governance solution with the potential to generate economies of scale and reduce financial costs in waste management. However, previous research has not yet focused on measuring the effectiveness of different types of cooperation on social and environmental outcomes. We analyse the effect of different types of IMC, ranging from indirect to collaborative, on Integrated Solid Waste Management (ISWM) indicators. Our embedded qualitative case study in the emerging metropolitan region of Cuenca-Azogues (Ecuador) found that municipalities that invested in more complex cooperation types achieved better integrated waste management performance, particularly on final disposal, citizen participation, inclusion of recyclers and environmental sustainability.

Various types of solid recovered fuels (SRFs) were investigated, then the waste was chemically leached and co-fired with coal and sewage sludge. Ashes with different properties and oxide compositions were used to explain the influence of various ash components (mainly sodium, potassium and calcium) on the Ash Fusion Temperatures (AFTs). Oxide compositions and empirical indices were determined and the effect of these data on the measured AFTs was investigated. An attempt to explain the effects of specific oxides on SRF melting temperatures using FactSage thermodynamic equilibrium software is presented. Thermodynamic equilibrium calculations are also used to predict the onset temperature of the molten phase, the percentage of molten phase at different combustion temperatures, and the possible solid phases that may exist at different temperatures. The mechanism of transformation of the inorganic substance of SRF turned out to be more complex than that of the mineral substance of coal, which resulted from the variable composition of the SRF. The character of temperature changes of the studied wastes after leaching in water and acetic acid in most cases is similar to the courses determined experimentally. For all investigated ashes from obtained the leaching of SRF wastes, the melting temperature decreases with the applied leaching. Potassium and sodium are the key elements causig the formation of low-melting silicates. Depending on the type of waste and leaching agent the lower the value of the B/A and α indices and the CaO content in ash, the lower the shrinkage temperature of the ash.

We investigated a novel processing technique of municipal solid waste incineration (MSWI) ashes. By using two thermodynamic driving forces - a strong alkaline activator and a compaction pressure, the otherwise relatively nonreactive MSWI ashes could form strong solids, with relatively high flexural and compressive strengths. The produced material was dense, with a low defect density. The effects of the compaction pressure range, the alkaline activator amount, and the MSWI fly ash to bottom ash ratio were examined. We also used 5 wt% class-C fly ash, 5 wt% class-F fly ash, and/or 1 wt% epoxy as additives. This study may open a door to advanced MSWI ash upcycling approaches, useful to environmental preservation and sustainability.

Currently, landfill is the most common, economical, and convenient method for municipal solid waste (MSW) disposal in countries around the world. MSW has a complex composition and special engineering characteristics, which lead to a very complex settlement mechanism in MSW landfills. This article reviews the description of this settlement mechanism in the existing literature and classifies it into stress-related mechanisms, biodegradation processes of organic substances, water-related mechanisms and physical and chemical processes of inorganic components. Based on the settlement mechanism, the influencing factors of landfill settlement were analysed, including the composition of MSW, physical parameters, environmental factors, and the operation mode of the landfill. Some practical engineering suggestions are obtained by analysing the influencing factors of MSW landfill settlement. Four commonmethods for studying the settlement of MSW landfills are presented, including laboratory experiments, in-situ settlement monitoring, theoretical analysis, and numerical simulation. We classified the existing settlement models into six categories: a soil mechanics, rheological, empirical, biodegradation, constitutive, and multiphase coupling models. Advantages and disadvantages of the different models and their applicability are compared and analysed. Moreover, limitations in the modelling process of MSW landfill settlement and future research directions are discussed.

In China, the impact of waste disposal facilities is always a cause of concern for the government and the public. Laogang Municipal Waste Disposal Area (LMDA), Shanghai, one of the largest municipal waste disposal areas in the world was selected as case in this study, and it was attempted to analyze the changes in the surface water quality, and map the impacted area by LMDA on surrounding streams from its operation period of 1993-2017. The results showed that, during the whole period, only biochemical oxygen demand (BOD

With the implementation of municipal solid wastes (MSW) source segregation collection policy, the combustible waste components are suitable for pyrolysis treatment to recover value-added energy such as gas or oil. In this research, the volatile compounds from MSW pyrolysis were reformed by the char obtained from the same process and the high-temperature flue gas (HTFG) of 1200 °C was supplying as heating resource and gasifying agent in a tailor-made experimental set-up. The final yields and properties of the syngas, char, and oil after reforming were investigated. Experimental studies showed that the composition of HTFG had a significant influence on the products. As the HTFG being CO

Dexing City is an important mining city in China, abounding in copper ore, lead ore, zinc ore, and other metal resources, and there are two large open-pit mines in its territory, Dexing Copper Mine and Yinshan Mine. The two open-pit mines have been expanding their mining production scale since 2005, with frequent mining activities; and the expansion of the pits and the discharge of solid waste will undoubtedly increase the land use and cause the destruction of vegetation. Therefore, we plan to visualize the change in vegetation cover in Dexing City from 2005 to 2020 and the expansion of the two open-pit mines by calculating changes of the Fractional Vegetation Cover (FVC) in the mining area using remote sensing technology. In this study, we calculated the FVC of Dexing City in 2005, 2010, 2015 and 2020 using data from NASA Landsat Database via ENVI image analysis software, plotted the FVC reclassified maps via ArcGIS, and conducted field investigations in the mining areas of Dexing City. In this way, we can visualize the spatial and temporal changes of vegetation cover in Dexing City from 2005 to 2020, and appreciate the situation of mining expansion and its solid waste discharge in Dexing City. The results of this study showed that the vegetation cover of Dexing City remained stable from 2005 to 2020, as the expansion of mining scale and mine pits was accompanied by active environmental management and land reclamation, setting a positive example for other mining cities.

The environmental risk of heavy metals in hazardous municipal solid waste incineration fly ash (FA) is one of the most important concerns for its safely treating and disposing. This study investigated the stabilization behavior of heavy metals in FA using coal fly ash (CFA) as an additive via hydrothermal treatment. The effects of water washing pre-treatment and FA/CFA ratio on leaching behavior, speciation evolution, and risk assessment of heavy metals were studied. The results showed that 96.6-98.0 % of Cl can be effectively removed by water washing pre-treatment and hydrothermal treatment. Most heavy metals (Cr, Cu, Ni, Pb and Zn) (91.5 %) were stabilized in the hydrothermal product, rather than transferred to liquid phase. Tobermorite can be synthesized by adjusting Ca/Si ratio with the addition of CFA. The heavy metals were transferred into more stable residue fractions with increasing CFA addition, which resulted in the significant reduction of leaching concentrations and risk assessment code (RAC) of heavy metals. Among, the product with 30% CFA exhibited the most superior performance with the lowest leaching concentrations of heavy metals and RAC was at no risk level (1). In addition, the economic performance of hydrothermal treatment exhibited a potential advantage by comparing with FA-to-cement, FA-to-glass slags and FA-to-chelating agentcement solidification/stabilization. Therefore, the hydrothermal treatment coupled with water washing pre-treatment would be a promising method for the detoxification of FA, as well as synergistic treatment of FA and CFA.

Due to rapid economic development and urbanisation, emerging megacities with dense populations have witnessed a significant increase in waste generation. Megacities face challenges in developing sustainable waste management systems. Considerable heterogeneity exists across megacities in management strategies. The two selected emerging megacities, Singapore (a city-state) and Shanghai, have similar developmental characteristics, but their waste management modes differ strikingly. This study assessed the two modes in terms of management strategies, environmental effects, economic costs, and social outcomes. Environmental footprint analysis and cost quantification were employed for the assessment based on public data. The research results would permit a deeper understanding of the long-term sustainability of each mode while considering the feasibility of implementation across different contexts. It was found that the waste management system in Singapore had a relatively lower environmental impact than Shanghai before Shanghai's new waste segregation and recycling policy in 2019. However, when the effect of fossil fuel substitution is taken into account, the environmental burden in Shanghai can be lowered more substantially than the one in Singapore. Although Shanghai had more economic burden for the waste segregation at source, it tended to implement the circular economy principles (e.g., reduce, reuse, and recycling) better and improve its sense of community significantly. Based on the practical experiences from the two representative megacities, suggestions for better waste management practices were provided for Singapore, Shanghai, and other emerging megacities with similar circumstances. In addition, challenges and opportunities related to household waste segregation and recycling were identified to guide future practices in emerging megacities.

The efficient strategy for waste conversion and resource recovery is of great interest in the sustainable bioeconomy context. This work reports on the catalytic upcycling of waste corrugated cardboard (WCC) into lactic acid using lanthanide triflates catalysts. WCC, a primary contributor to municipal solid wastes, has been viewed as a feedstock for producing a wide range of renewable products. Hydrothermal conversion of WCC was carried out in the presence of several lanthanide triflates. The reaction with erbium(III) triflate (Er(OTf)

Large amount of gelatin can be extracted from the solid waste in leather industry. The advanced application of such gelatin is always desired by the leather industry, but remains challenging. Considering the urgent requirement of biodegradable plastic film, in this study, the gelatin extracted from waste skin scrap in the leather industry was used to fabricate a waste gelatin-based film with a high gelatin content, excellent mechanical performance, and autonomous biodegradability in natural soil. The film was prepared by introducing covalent bonds and metal-ligand bonds to the gelatin matrix. These covalent bonds, metal-ligand bonds, and inherent hydrogen bonds in the gelatin matrix serve as multiple sacrificial bonds for effective energy dissipation giving the waste gelatin-based film excellent mechanical parameters with the highest fracture stress of ≈ 32 MPa, maximum fracture strain of ≈1.25 mm/mm, and a high Young's modulus of ≈ 471 MPa, which are significantly higher than those of the original gelatin film (fracture stress ≈ 4 MPa, fracture strain ≈ 0.70 mm/mm, and Young's modulus ≈ 22 MPa). Owing to the water resistance of covalent bonds and metal-ligand bonds existed in gelatin matrix, the gelatin film possesses good water resistance. Additionally, after use, the fabricated film can completely biodegrade in natural soil in approximately 7 weeks. This strategy not only provides a valuable recycling solution for the gelatin from the unwelcome solid waste of the leather industry, but it also broadens the range of ecofriendly and cost effective biodegradable films available.

Material recovery facilities (MFRs) play an important role in today's waste management systems to maximize recycling efficiency for several waste materials. These facilities face multiple challenges, often due to a poor understanding of the mechanisms occurring within the sorting equipment. Improving modeling techniques of these unit operations appear to be a promising opportunity to mitigates these challenges. Mechanical sorting efficiency of municipal solid waste is often predicted from simple transfer coefficients, which are obtained for a specific set of operating conditions of the sorting equipment and sorting sequence configuration. When these transfer coefficients are used in situations that are different to those in which they were obtained, poor predictions can be expected. To overcome these limitations, a new predictive tool, based on the integration of mechanistic models and transfer coefficients, is presented. Mechanistic models are developed only for the most influential unit operations in a MRF, in order to predict their sorting efficiency based on the physical phenomena occurring. Integration of these models with the use of transfer coefficients for the other unit operations allows the entire predictive tool to remain as simple as possible while providing high prediction accuracy and flexibility. The use of the tool is validated with a real case study of a material recovery facility. Results indicate a good prediction of the mass flows of the facility. Moreover, a new modeling technique is proposed for the representation of a ballistic separator based on the shape factor of the waste items.

Controlled Ecological Life Support System (CELSS) is a closed artificial ecosystem which can regenerate oxygen, food, water and other substances for crew survival in long-term space missions. Solid organic waste is a vital resource pool for material reuse and recycling in CELSS. In this study, solid wastes including wheat straw and food waste were disposed via aerobic composting under functional microbial agent inoculation. Compared to tests with a commercial microbial agent addition and without exogenous microorganisms, system performance was promoted by the self-developed microbial agent significantly which exhibited the highest composting temperature (67.4 ± 1.5 °C) and longest thermophilic period (7 days). And treatment with self-developed microbial agent showed the highest values in volatile solid reduction, C/N reduction, germination index (124.83 ± 13.25%) and total available nutrient content (47.45 ± 1.69 g/kg), which suggested the feasibility of compost product to be used for crop cultivation. Moreover, shifts of microbial community in phylum and genus levels were observed. Microbial agent augmentation led to high quality and safe compost product after a short composting period (30 days) without leaching, which suggested an efficient way to promote the recycling and recovery of solid waste in CELSS.

Fly ash produced from incineration of municipal solid wastes (MSW) contains heavy metals, such as Cd and Pb, that make this material difficult to manage and dispose of safely. Because the composition of fly ash is similar to cement raw meal, partial replacement of raw meal with fly ash may be a feasible way to reduce the health and environmental hazards of the ash, provided that the heavy metals can be effectively stabilized in the solid phase. This research employs proprietary thermochemical software to simulate the thermodynamic behavior and single-step fixation of Cd and Pb in industrial cement kilns. The effect of Cd, Pb and Cl loadings on the fixation and/or evaporation of Cd and Pb during the sintering process is analyzed using data from industrial cement kilns. A simplified model is created based on elemental mass balance to evaluate multi-step fixation of Cd and Pb with cement kiln dust recycle.The results indicate that Cd forms Cd(OH)

The use of bio-plastic-based packaging as an alternative to conventional plastic packaging is increasing. Among the plethora of different bio-based plastics, the most relevant ones are those that, at the end of their life, can be treated with the organic fraction of municipal solid waste. Even in these cases, their impact on the waste processing and recycling is not always positive. This study aim to assess on a laboratory scale the influence on combined anaerobic digestion and composting industrial processes of a bio-based plastic film, namely cellulose acetate (CA), in pure and modified (additions of additive) forms. CA films were mixed with organic waste and subjected to: (i) anaerobic digestion; (ii) active composting and (iii) two stages of curing composting. Anaerobic digestion and composting were monitored through methane yield and oxygen uptake respectively; additionally, the bio-plastics degree of disintegration was assessed during all the processes. The final disintegration of pure and modified CA was 73.82% and 54.66%, respectively. Anaerobic digestion contributes to the disintegration of the material, while aerobic treatment appears to be nearly ineffective, especially for modified CA. The presence of cellulose acetate during anaerobic digestion of food waste increased the methane yield by about 4.5%. Bioassay confirmed the absence of possible toxic effects on the final compost from the bio-plastic treatment. Although bio-based materials are not the only solution to plastic pollution, the findings confirm the need to upgrade the organic waste treatment plants and the necessity to revise the requirements for the use of compost in agriculture.

The enormous discharge of industrial waste seriously hinders the sustainable development of cities. However, most studies only involve a single or limited category of industrial pollutants, ignoring the environmental pressure caused by multiple resources and environmental factors. This paper combines input-output analysis and ecological network analysis to construct an industrial waste metabolic input-output (IWMIO) model, which explores the industrial waste discharge and discharge relationships among different sectors in Jiangsu Province from the three aspects of industrial wastewater, industrial waste gas, and industrial solid waste. The results show that the indirect discharge of industrial waste is greater than the direct discharge in the industrial waste metabolism system. TI (Tertiary industry), CI (Chemical industry), SPM (Smelting and pressing of metals), and PSEH (Production and supply of electricity and heat) dominate the industrial waste metabolism system. In addition, MWC (Mining and washing of coal), MNMP (Manufacture of non-metallic mineral products), SPM (Smelting and pressing of metals) have more mutualism and competition relationships with other sectors, so the control of industrial waste discharge in these sectors contributes to achieving emission reduction targets. Based on the research results, this paper proposes corresponding policy recommendations such as considering both direct and indirect emissions of sectors when formulating waste reduction policies and developing pertinent industrial waste reduction programs based on the characteristics of the identified sectors. The results of this paper are helpful to identify the dependence and influence relationships of various sectors in the industrial waste metabolism system, promote industrial waste discharge control, and provide theoretical support for the adjustment of industrial structure and the formulation of related policies in Jiangsu Province.

Banana wastes can be valorised in bioethanol due to its high content in cellulose (more than 30% of total on a dry basis) and hemicelluloses (25% of total). Large amount of these wastes is generated during the banana cultivation and harvesting stage. This study proposes the use of, beside conventional acid sulphuric, different organic acids (tartaric, oxalic and citric) during acid pretreatment step, to suppress the unwanted compounds formation and improve bioethanol production. Instead, bioethanol production generates a solid waste flow that is managed in an anaerobic digestion plant, obtaining biogas, to be converted into energy, and digestate, considered as a potential biofertiliser. Life cycle assessment methodology is used to analyse the environmental profiles of four valorisation scenarios to produce bioethanol from banana peel waste. According to the results, reported per kilogram of bioethanol, the citric acid-based scenario has the worst environmental profile due to the background processes involved in the acid production (around 55% for most impact categories). Conversely, the oxalic acid-based scenario has the best environmental profile, with a decrease of around 20% and 35%, depending on the impact category, compared to the citric acid scenario. The energy requirements production (mostly thermal energy) is the main hotspot in numerous subsystems regardless of the scenario (ranging from 30% to 50% depending on the impact category). Therefore, the use of renewable energy sources to satisfy energy requirements combined with an energy optimisation of the valorisation strategies through the reuse of some internal steams, is proposed as improvement activities This research has been partially supported by the SENSE project granted by FEDER/Spanish Ministry of Science, Innovation and Universities, Spanish National Research Agency (CTQ2016-75136-P) and by the project Enhancing diversity in Mediterranean cereal farming systems (CerealMed) funded by PRIMA Programme and FEDER/Ministry of Science and Innovation – Spanish National Research Agency (PCI2020-111978). B. Santiago thanks to the Spanish Ministry of Science, Innovation and Universities for financial support (Grant reference BES-2017-081715). The authors belong to the Galician Competitive Research Group GRC 2013-032 and to CRETUS Strategic Partnership (AGRUP2015/02). All these programmes are co-funded by Xunta de Galicia and FEDER (EU) SI

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.

Research and practice on concrete incorporating solid wastes have found many advocates in recent years. Despite significant advancements, the connecting link between the performance of concrete incorporating solid wastes and its environmental impacts is not fully captured. The current review article aims to address the dependency between concrete performance and the potential environmental impacts of concrete made with solid wastes. A systematic review of previous life cycle assessment (LCA) publications was performed with a focus on outlining the importance of including mechanical and durability properties of such type of concrete in obtaining robust LCA results. The data on four types of solid wastes, including construction and demolition waste, municipal solid waste incineration, tire rubber, and polyethylene terephthalate, were reviewed. Research gaps and future opportunities were discussed to advance the knowledge of concrete incorporating these solid wastes. Finally, recommendations were proposed to provide a guideline for construction materials stakeholders to develop a robust comparative LCA of the concrete, particularly that made with solid wastes.

The environmental risk assessment and the factors influencing heavy metals (HM) in the soil at the municipal solid waste landfill sites (MSWLs) were studied by literature review, field survey, and statistical methods. The results indicated that the dominant HM contamination in the soil at the MSWLs was caused by chromium (Cr) with the Nemero index values (PI) from 22.7 to 44.3 and zinc (Zn) with the PI from 0.7 to 9.8. There were significant differences in the Cr, mercury (Hg), lead (Pb), Zn, and arsenic (As) concentrations between soil samples from sanitary and non-sanitary landfills (NSLs) where HM contamination (PI = 10.9) was more obvious. As (CRA

To properly manage municipal solid waste (MSW) and meet the country's biogas target, it is necessary for the government to prioritize their support to areas/provinces that have high resource potential. Therefore, this work designed a holistic approach for nationwide area-based organic MSW to biogas potential estimation. The total biogas power potential was ranged from 999 MW in 2021 to 1,652 MW in 2037. Moreover, priority setting on area-based biogas implementation was proposed, based on its resource potential to efficiently promote such technology. To achieve current biogas target of the country, the study identified 28% of national area coverage as priorities for actual execution, which could offset averagely 3% per year. To support design and planning purposes, an area with around 45,000 capita is recommended for developing 1 MW of MSW to biogas power plant using anaerobic digestion technology. The methodology development from this research revealed the link between resource potential and area-based prioritization framework that could be adopted in any growing economies to couple waste management with renewable energy production.

In light of the adoption of recent global policies and strategies for a more sustainable food waste management system and a greater control of environmental impacts, this study describes a circular bioeconomy plant model, currently operating in South Italy, for treatment and enhancement of organic fraction of municipal solid waste. The key basis for plant activity is dry anaerobic digestion of separately collected organic fraction of municipal solid waste (SC-OFMSW) followed by digestate composting process. Biomethane for use in the transport sector is obtained by biogas cleaning and upgrading, while high-quality compost for organic farming is produced by digestate composting. Plant activities are completed by the transformation of part of the produced waste into refuse derived fuel (RDF) to be allocated to waste-to-energy plants and the treatment of odour emissions which allows the recovery of ammonium sulphate as a fertilizer. A rooftop photovoltaic system supplies most of electric energy needed by the plant. For plant activities relative to 2020, carbon footprint was equal to -112 kg CO

The unprecedented population increase brings several consequences to the environment, including the rise of urbanization levels and municipal solid waste (MSW) production - one expects that it may reach 3.4 billion tons per year by 2050. This paper contributes to the debate of efficiency measurement of MSW utilities management using the Portuguese case study. Our objectives are twofold. First, we assess the efficiency levels of municipalities in MSW collection through the Data Envelopment Analysis model, choosing total costs, staff, and vehicles as inputs, and the quantity of MSW collected (selective and refuse waste) as outputs. The efficiency results point to an average inefficiency level of about 35% and potential cost savings of over €96 million yearly. Second, by using a set of fifteen performance indicators monitored by the regulatory agency, we evaluate their relationship with the efficiency of MSW utilities, through the order-m model. Our results suggest that, in opposition to the management model, the rural/urban nature of councils helps explain part of the inefficiency. In general, the conditional-to-unconditional efficiency ratios reached values statistically different from 1, meaning that those indicators help explaining their efficiency distribution and the benchmarks profile, and need to be considered in future performance analyses. Remarkable and influential indicators include the accessibility to the service (average ratio = 0.95), the recycling rate (0.94), the monetization of the vehicle fleet (0.92), the pollution resulting from greenhouse gas emissions of waste collection vehicles (0.81), and council size measured by the population or the number of households (0.47).

The study presents research focused on factors influencing performance in municipal solid waste management (MSWM) at the level of individual municipalities in the Czech Republic. Czech municipalities possess a specific municipal structure that is characteristic of high fragmentation, in which municipalities spatially resemble conglomerates. In spite of their typically small size, they cling to their own independence and are thus willing to assume full responsibilities in MSWM. In recognition that expenditure on MSWM is the primary concern to municipalities and that there are secondary environmental interests in waste separation, four alternative models of waste management service production are considered for a sample of 470 Czech municipalities that capture performance from different standpoints. Performance in MSWM is assessed by dint of data envelopment analysis (DEA). Full frontiers are employed simultaneously with order-m partial frontiers and resulting unconditional-to-conditional scores are investigated for the influence of twelve contextual factors describing operating conditions of MSWM. The analysis accounts for the fact that in this case the twelve contextual factors are found non-separable from the process underpinning the provision of MSWM. It is revealed that performance in MSWM improves with the availability of recycling consolidation facilities, but programs inciting waste separation or green waste collection do not bring about the anticipated effect. The findings are instrumental in planning of MSWM and equip municipalities with policy advice that is useful in improving performance in MSWM and subsequently in reaching ever stricter environmental targets requested over time at both national and international levels translated to a municipal level.

Openmunicipal 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 (

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.

In light of China's rising environmental governance focus on household waste recycling, this article analyses a novel recyclable waste recovery scheme, Ant Recovery, in Changchun, Jilin Province. In contrast to other recyclable waste collection systems, Ant Recovery emerged as a bottom-up venture established by members of the informal recycling sector in cooperation with the local recycling association. To assess the scheme's performance, the analysis uses field research data obtained over 21 days of observatory and questionnaire surveys at one of Ant Recovery's mobile collection points. Based on data from 1,501 documented recyclable waste transactions, the analysis indicates a median recovery rate of 438.4 kg/hour at the surveyed recovery station. Extended to the entire scheme's network in Changchun, the figure extrapolates to 2,034.6 metric tons/day, which approximates to roughly 94% of waste recyclables generated by the city's households. These achievements essentially result from two factors: (1) A beneficial policy environment established by central and local regulations and (2) AR's operational compatibility with daily routines and profit orientation of waste recyclable delivering stakeholders. In comparison to many other recycling systems in China, the alternative model in Changchun appears to be indigenous with little requirement for novel organisational structures or high capital/ overhead costs.

High-solid anaerobic digestion of the very small particle fraction of mechanically-sorted organic fraction of municipal solid waste (OFMSW) was examined in mesophilic digestion tests in a conventional laboratory (0.013 m3) and a pilot (0.300 m3) reactor. The non-biodegradable and recalcitrant molecules together with the low protein and starch contents of the small-particles of OFMSW limited the methane generation potential of substrate. In the conventional AD system, methane yields remained low at 0.139 m3kgVS-1 due to formation of a non-reacting layer on digestate surface, which restricted utilization of the available in OFMSW digestible organics. The absence of surface solid crust in the pilot unit favoured consumption of a greater proportion of volatile solids of the OFMSW. Dry AD was remarkably stable over the entire period and negligibly effected by the toxic H2S yields. Methane generation (0.167 m3kgVS-1) was increased 1.2-fold compared to the conventional system due to a better mixing of substrate and microorganisms achieved inside the pilot reactor, which led to an increase of the digested volatile organics. Digestate presented low stability and high heavy metal content, both of which restrain its implementation as soil conditioner or fertilizer in agriculture. A secondary co-digestion treatment may be required for the neutralization of digestate.

Mechanical sorting plays a pivotal role in current municipal solid waste management systems for resource recovery. However, material recovery facilities, generally face several challenges in meeting quality standards for multiple waste fractions. Improving these facilities requires a better understanding of municipal solid waste physical characteristics, since they are directly targeted by mechanical sorting unit operations. Three waste physical properties (bulk density, particle size and shape factor) were characterized for several recyclable materials. Narrow ranges of densities were observed for similar waste materials, while the particle size distributions were found to vary widely. Statistical parameters were determined for these two properties. A novel approach, based on the void fraction of a waste item, is proposed to quantify the shape factor. Potential applications of the characterization results for improving mechanical sorting are demonstrated through the analysis of the recovery of corrugated cardboards and multilayer cardboards in a material recovery facility.

Present study characterizes municipal solid waste incineration bottom ash (MIBA) from three incineration plants in Delhi with an intent to serve the dual objectives: a) assessing the disposal/reuse options for Delhi MIBA, b) evaluating variability in results across the countries (including India) and assessing if is significant enough to influence the fate of MIBA of varied origin. A review on leaching studies of MIBA (50 research papers) was conducted which aided in achieving both the objectives. Delhi MIBA samples were analysed for chemical composition. The two commonly adopted leaching tests i.e., TCLP and EN 12457–2, were conducted and the results were checked against regulatory threshold levels (RTLs) to achieve the first objective. Leaching concentration of the contaminants was compared with the compiled literature and RTLs to accomplish the second objective. The compendium of literature most importantly revealed the physicochemical parameters which are pivotal in determining the fate of MIBA but have been missing from many studies. Ten such parameters were identified: Cr, Cu, Mo, Sb, Cl - , SO 4 2- , Cd, Pb, Ni and Zn and are referred as contaminants of concern (CoCs). Delhi MIBA was found suitable for disposal to non-hazardous waste landfills and unsuitable for unrestricted reuse. CoCs identified in Delhi MIBA were identical to those observed in literature (except Cd, Pb and Zn). The variability in leaching concentration of CoCs, observed from comparative assessment of results, spanned nearly 2 to 3 log 10 magnitudes for Cu, Cr, Pb, Sb and Zn while 1 to 2 log 10 magnitudes for Mo, Cl - and SO 4 2- .

Municipal solid waste incineration (MSWI) fly ash disposal is an urgent task with some technical bottlenecks. In this study, a novel pressure-assisted sintering method was employed to treat the MSWI fly ash. A series of pressure-assisted sintering experiments were carried out by varying mechanical pressures and sintering temperatures, and their properties of compressive strength, density and heavy metals leaching behavior were determined to screen out the optimal conditions. Instrumental analysis of XRF, SEM, XRD and TEM-EDX and calculation kinetics were conducted to explore the enhancement mechanism of pressure-assisted sintering. With the help of mechanical pressure, a high-strength ceramic product was produced from MSWI fly ash sintered at a low temperature (400 °C), which never occurred in the conventional low-temperature sintering process. Maximum compressive strength of 218.30 ± 4.08 MPa was obtained at 400 °C and 100 MPa, which was much higher than conventional construction materials of brick and cement. In addition, the leaching concentrations of heavy metals obtained from pressure-assisted sintering process were lower than the standard limitation. The SEM and XRD results revealed that the increased mechanical properties and the decreased heavy metals leaching concentration were mainly attributed to the increased density and crystalline degree. The kinetics calculation results indicated that the sintering activation energy was much lower than the sintering process without pressure, suggesting surface diffusion and grain boundary diffusion were main sintering mechanisms in the pressure-assisted sintering process. These findings proved that pressure-assisted sintering could be a promising method to treat fly ash together with producing high-value building materials.

In recent years, concerns about the increasing generation of municipal solid waste, together with related health and environmental issues and regulatory changes, have motivated significant alterations in the provision of waste management services, such as the introduction of selective collection (by type of waste). However, these changes may impact on service costs and/or efficiency. The present study was undertaken to analyse the efficiency of the waste management service in Spain, using data from 283 municipalities for the period 2005–2015. The analysis consists of two phases: first, the application of panel data order-m frontiers, that allows to obtain a homogeneous estimation of efficiency based on the input–output relationship at the production process (Surroca et al., 2016), and second, the use of bootstrapped truncated regression, considering different municipal sizes. The results obtained show that cost efficiency is increased with selective collection and by certain political and socio-economic factors of the local governments, concretely with the government by a progressive party, coalition governments, a greater financial independence, a greater tourist and industrial activity and a greater proportion of women and of foreign-born residents in the municipality. We also show that municipal direct provision is the least efficient management form for this service. The main contribution made by this study is to examine the influence of different elements of service output (i.e., selection by type of waste vs. non-selection) on cost efficiency.

The aim of the study was to assess the effects of high concentrations (10 % w/w, data projected for 2030) of commercial bioplastics, i.e. starch based shopping bags (SBSB) and polylactic acid (PLA) tableware, in the organic fraction of municipal solid wastes (MSW) on compost quality obtained by pilot-scale dry mesophilic anaerobic digestion and subsequent composting of the digestate. After the biological processes, 48.1 % total solids (TS) of SBSB and 15 % TS of PLA degraded, resulting in a high bioplastics content (about 18 % TS) in compost. Subsequent compost incubation in soils indicated that bioplastics degraded by pseudo-zero order kinetics (0.014 and 0.010 mg C cm−2 d-1 for SBSB and PLA, respectively), i.e. complete degradation was expected in 1.6 years (SBSB) and 7.2 years (PLA), confirming the intrinsic biodegradability of bioplastics. Nevertheless, enhancing the rate and amount of bioplastics degradation during waste management represents a goal to decrease the amount of bioplastics reaching the environment.

Rapid population and economic growth, changes in consumption pattern etc. have become major contributing factors to severe municipal solid waste generation globally. Thus, various methods are being employed to manage the incessant municipal solid waste generation for a sustainable solid waste management and one of the viable approaches is the recycling option. The main objective of this paper is to determine the cost benefit analysis of setting up a recycling facility for the processing of various wastes for use as raw materials by industries. The cost benefit analysis was carried out based on historic data obtained from the municipality and some recent waste composition data. The overall analysis was done using Excel software. From the Excel software analysis, Internal Rate of Return on investment was 42%, Internal Rate of Return on equity was 98% and Net Present Value was R 63, 420,000 (USD$ 4646225.33). In ascertaining the result obtained from the Microsoft Excel, three data analysis and technical computing software (MATLAB, Python, and R-Studio) were employed. This was necessary to compare and validate the cost-benefit indicators (Net Present Value and Internal Rate of Return). Besides, evaluating the performance of each software with regards to the cost-benefit evaluation is ideal for a recycling plant like this to establish the feasibility of the project. Moreover, sensitivity analysis was conducted, and a breakeven point of 211 tons of waste was obtained. In addition, the total benefit of recycling was valued and was given as R 486,008,582.85 (USD$ 35605572.16). From the overall analysis, it was observed that the IRR and Net Present Value were alike, about 677 potential jobs could be created on the project and the Net Present Value > 0. Based on the overall analysis, it was concluded that the project is viable.

As part of the global effort to achieve the Sustainable Development Goals (SDGs), countries are attempting to minimize landfilling, and instead, promote recycling. The percentage of household waste collected for recycling and mass (metric tonnes) of recyclable material collected by municipalities have been defined as indicators to measure progress. However, by 2019, data were available for only 70 of the 193 United Nations' member states and most of the data accounts for countries in the Global North. Presented here are the first national, and locally disaggregated municipal recycling data from Chile. Between 2013 and 2017, less than 0.8 per cent of total household waste was separatedly collected for recycling. An econometric model is used to analyse factors influencing local-level separate collection among municipalities that have a recycling service. The variance of separate collection rates is explained by education, total residual waste sent to landfills, duration of recycling services, composting, percentage of urban population, and by regional disparities.

Since the 1980′s, some Mexican municipalities have subcontracted waste collection services to private companies, with an eye on increasing the efficiency of this service. However, the impact of private management on the Mexican waste sector performance has not been evaluated. In this study, the efficiency of waste collection in Mexico was analyzed to test the hypothesis that private companies are more efficient at waste collection than municipal governments. A two stage double bootstrap Data Envelopment Analysis (DEA) was applied to a sample of 1,626 municipalities. In the first stage, unbiased efficiency scores were calculated, and in the second stage, these scores were regressed against a set of environmental covariates which were thought to affect efficiency, including a dummy variable to identify the municipalities where waste is collected by a private company. Results suggest that private waste collection companies are more efficient than municipal governments. Other environmental variables such as population density, average household income, and tourism were also found to affect waste collection efficiency. The analysis also indicates that curbside collection is associated with a higher efficiency, while separate collection of waste is negatively correlated to efficiency.

To elucidate the mechanism driving selective autophagy of protein aggregates, or "aggrephagy," Ma et al. (2022) identify chaperonin TRiC subunit CCT2 as a receptor that specifically promotes the clearance of solid aggregates, but not liquid-like condensates, in a ubiquitin-independent manner.

Gasification of wet municipal solid waste (MSW) coupled with in-situ CO2 capture is an attractive option for MSW disposal, allowing chemical and energy recovery. In this study, the Ni-CaO based catalysts were prepared with waste marble powder (WMP) as an alternative to CaO and promoted by different transition metals (i.e., Fe, Cu, Co and Zn). The bimetallic catalysts were prepared by the impregnation method and characterized by different analytical techniques. The catalyst performance for wet MSW gasification was evaluated in a fixed-bed reactor at optimized conditions (850 °C and 50% moisture content of MSW). The results revealed that the addition of Ni-WMP catalyst greatly enhanced the dry gas yield (DGY), H2 yield, carbon conversion efficiency (CCE) and reduced the tar content from 0.73 to 1.16 N.m3/kg, 212 to 509 mL/g, 61.70% to 76.40% and 9.11 to 3.9 wt%, respectively, compared to without catalyst. In contrast to the Ni-WMP catalyst, the transition metal promoted catalysts showed higher catalytic activity towards H2 yield (549–629 mL/g), DGY (1.19–1.30 N.m3/kg), and lower tar content (3.45–2.93 wt%). The results revealed that Co promoted bimetallic catalyst performed better than Fe, Cu and Zn promoted catalysts. The tar content produced was also analyzed via GC–MS (gas chromatography-mass spectrometry) to understand the effect of different catalysts on tar composition. According to experimental results, the bimetallic promoted catalysts can be ranked as Ni-Co-WMP > Ni-Cu-WMP > Ni-Fe-WMP > Ni-Zn-WMP based on H2 yield and tar removal.

The physical and mechanical properties of waste ground were examined at 14 locations across 4 inert waste landfills in Japan with the goal of establishing a safe and cost-effective design methodology specific to inert waste landfills. Composition analysis, basic physical properties, angle of repose, CASPOL impact value tests, and in situ direct shear tests were conducted. Inert wastes were comprised of three main components: fibrous, granular, and soil-like content, and their compositions varied between 3.6–54%, 13–45%, and 43–74%, respectively. As the fibrous content and age after reclamation increased, the water content increased but the percentage air voids decreased. The impact value (Ia), which is an indicator of the bearing capacity, increased as the dry density increased. For all locations, the angle of repose after avalanche (αa) was found between 34 and 44°. In direct shear tests, the cohesion (c) and internal angle of friction (φ) ranged from 2 to 21 kN/m2 and 22–59°, respectively. The shear stresses obtained from these c and φ values were higher than those for the municipal solid wastes, particularly for landfills with fibrous fractions ranging 14–31% under a normal stress of 25.55 kN/m2. c increased and φ decreased as the dry density increased. The correlation calculated for c and φ with Ia for inert waste landfill were c = 4.10Ia − 21.32 and φ = −4.61Ia + 82.37. Finally, the utilization of the results obtained in this study is discussed in three design stages: planning, landfilling, and future expansion.

This paper reports the first known comprehensive survey of combustion operating conditions across the wide range of municipal waste-to-energy facilities in the U.S. The survey was conducted in a step-wise fashion. Once the population of 188 units operating at over 70 facilities was defined, this population was stratified by distinguishing characteristics of combustion technology. Stratum-level estimates for operating conditions were determined from data collected in the survey. These stratum-level values were weighted by corresponding design capacity share and combined to infer national-level operating parameter estimates representative of the overall population. Survey results show that typical municipal waste-to-energy combustion operating conditions in the U.S. are (1) furnace temperature above 1160 °C, (2) gas residence time above 2.4 s, (3) exit gas concentrations of nearly 10% for oxygen (dry basis), and (4) over 16% for moisture. These operating parameter values can serve as benchmarks for laboratory-scale studies representative of municipal waste-to-energy combustion as typically practiced in the U.S.